C-Motion - 3D Motion Analysis Software

Research Papers - Analysis Techniques used in Visual3D and studies using Visual3D

Books

Citation for Visual3D calculations or processes

Uses or References to Visual3D (or Move3D)

Foot studies or research papers

Back or spine studies

Biomechanics - kinematics, kinetics, methods, algorithms, modeling

Marker sets and placement papers

Gait or lower body related papers

Biomechanics and robotic devices

Lab calibration or CalTester related papers

Submit Your Own Article Here...

Books:

Chapman AE "Biomechanical Analysis of Fundamental Human Movements"

2008 - Human Kinetics

Unlike previous biomechanics texts that have taken a mechanical concept and identified activities in which the concept is implicated, Biomechanical Analysis of Fundamental Human Movements takes a contrary approach by focusing on the activities and then identifying the biomechanical concepts that best facilitate understanding of those activities. Superbly illustrated with more than 140 figures depicting the critical points of biomechanical analysis, this two-color text is an invaluable tool for those pursuing the study of advanced quantitative biomechanics. It presents a clear introduction to the principles that underlie all human motion and provides a complete study of fundamental human movements and their components.

Reference

Richards J "Biomechanics in Clinics and Research: An interactive teaching and learning course"

2008 - Elsevier

This title is directed primarily towards health care professionals outside of the United States. It is a unique resource, which combines an exceptional online course with a practical and accessible book. The course is thoroughly integrated with the text and the many high-quality animations, interactive tests and clear explanations will enable you to gain a confident understanding of the clinical aspects of biomechanics.

Reference

Helliwell, Woodburn, Redmond, Turner, Davys "The Foot and Ankle in Rheumatoid Arthritis"

2008 - Elsevier

Comprehensive and accessible, this unique book emphasizes a practical and evidence-based approach to the foot and ankle in rheumatoid arthritis. Information is concise, up to date, and well illustrated. The team of authors consists of rheumatologists and podiatrists based at the highly respected Foot and Ankle Studies in Rheumatology (FASTER) programme, with contributors including both surgeons and orthotists. A companion DVD contains many video clips of examination and injection techniques and gait analyses, additional downloadable images, assessment tools and an interactive injection resource.

Reference

Robertson G., Caldwell G., Hamill J., Kamen G.,Whittlesey S. "Research Methods in Biomechanics"

2004 - Human Kinetics

This text provides a firm foundation in the biomechanical methods and tools necessary for quantifying human movements. Research Methods in Biomechanics is an invaluable resource for developing and seasoned researchers wishing to hone their skills and learn new techniques in the collection, analysis, and interpretation of data. The reference shows how the laws of motion are applied to complex human movements. The text demonstrates how to combine segments to obtain limb or total-body measures. All the material is presented in such a way that you need only basic knowledge of Newtonian mechanics and vector algebra to benefit.

Reference

Hamill J, Knutzen K "Biomechanical Basis of Human Movement"

2003 - Lippincott Williams & Wilkins; 2 edition

This introductory text in biomechanics integrates basic anatomy, physics, calculus, and physiology for the study of human movement. Organized into three parts (Foundations of Human Movement, Functional Anatomy, and Mechanical Analysis of Human Movement), this text is considered to be a \"higher\" level biomechanics book as it can be used in both upper level undergraduate and graduate courses. NEW TO THIS EDITION: New coverage of physical activity and bone formation, osteoarthritis, osteoporosis, factors influencing force and velocity development in the muscle, and the effect of training on muscle activation New and updated illustrations include applications from ergonomics, orthopedics, and exercise (supplemented with references from the current biomechanics literature)

Reference

Citation for Visual3D calculations or processes:

Merican AM, Amis AA "Iliotibial band tension affects patellofemoral and tibiofemoral kinematics"

2009 - Journal of Biomechanics Volume 42, Issue 10, 22 July 2009, Pages 1539-1546

The iliotibial band (ITB) has an important role in knee mechanics and tightness can cause patellofemoral maltracking. This study investigated the effects of increasing ITB tension on knee kinematics. Nine fresh-frozen cadaveric knees had the components of the quadriceps loaded with 175 N. A Polaris optical tracking system was used to acquire joint kinematics during extension from 100° to 0° flexion. This was repeated after the following ITB loads: 30, 60 and 90 N. There was no change with 30 N load for patellar translation. On average, at 60 and 90 N, the patella translated laterally by 0.8 and 1.4 mm in the mid flexion range compared to the ITB unloaded condition. The patella became more laterally tilted with increasing ITB loads by 0.7°, 1.2° and 1.5° for 30, 60 and 90 N, respectively. There were comparable increases in patellar lateral rotation (distal patella moves laterally) towards the end of the flexion cycle. Increased external rotation of the tibia occurred from early flexion onwards and was maximal between 60° and 75° flexion. The increase was 5.2°, 9.5° and 13° in this range for 30, 60 and 90 N, respectively. Increased tibial abduction with ITB loads was not observed. The combination of increased patellar lateral translation and tilt suggests increased lateral cartilage pressure. Additionally, the increased tibial external rotation would increase the Q angle. The clinical consequences and their relationship to lateral retinacular releases may be examined, now that the effects of a tight ITB are known.

Tucker CA, Bagley A, Wesdock K, Church C, Henley J, Masiello G "Kinematic Modeling of the Shoulder Complex in Tetraplegia"

2008 - Topics in Spinal Cord Injury Rehabilitation, Volume 13, Number 4 / Spring 2008 - Contemporary Perspectives of Upper Limb Management

In comparison to other joints in the human body, the shoulder complex is particularly reliant on the coordination of active muscle forces to generate both movement and stability during activities using the upper extremities. The resultant imbalance of muscle forces across the shoulder, coupled with the increased reliance on the shoulder for functional mobility, puts the individual with tetraplegia at great risk for developing shoulder pathology. The ability to quantify the movement of the shoulder, and in particular the sequence of shoulder complex movement components within functional tasks, can provide information to better inform clinical and surgical decision making. In this article, we will discuss the impact of tetraplegia on shoulder biomechanics and function, provide an overview of general principles and current status of kinematic modeling of the shoulder complex, and describe emerging applications of quantitative motion analysis of the shoulder complex.

Hidler J, Wisman W, Neckel N "Kinematic trajectories while walking within the Lokomat robotic gait-orthosis"

2008 - Clinical Biomechanics 23 (2008) 1251-1259

Background One of the most popular robot assisted rehabilitation devices used is the Lokomat. Unfortunately, not much is known about the behaviors exhibited by subjects in this device. The goal of this study was to evaluate the kinematic patterns of individuals walking inside the Lokomat compared to those demonstrated on a treadmill. Methods Six healthy subjects walked on a treadmill and inside the Lokomat while the motions of the subject and Lokomat were tracked. Joint angles and linear motion were determined for Lokomat and treadmill walking. We also evaluated the variability of the patterns, and the repeatability of measuring techniques. Findings The overall kinematics in the Lokomat are similar to those on a treadmill, however there was significantly more hip and ankle extension, and greater hip and ankle range of motion in the Lokomat (P < 0.05). Additionally, the linear movement of joints was reduced in the Lokomat. Subjects tested on repeated sessions presented consistent kinematics, demonstrating the ability to consistently setup and test subjects. Interpretation The reduced degrees of freedom in the Lokomat are believed to be the reason for the specific kinematic differences. We found that despite being firmly attached to the device there was still subject movement relative to the Lokomat. This led to variability in the patterns, where subjects altered their gait pattern from step to step. These results are clinically important as a variable step pattern has been shown to be a more effective gait training strategy than one which forces the same kinematic pattern in successive steps.

Goulermas JY, Howard D, Nester CJ, Jones RE, Ren L "Regression Techniques for the Prediction of Lower Limb Kinematics."

2005 - Journal of Biomechanical Engineering, Volume 127, Issue 6, pp. 1020-1024

Cappello, A., Cappozzo, A., La Palombara, P.F., Lucchetti, L., Leardini, A. "Multiple anatomical landmark calibration for optimal bone pose estimation."

1997 - Human Movement Science. 16: 259-274

Kepple, T. Siegel , K., & Stanhope, S. "The use of two foot-floor models to examine the role of the ankle plantar flexors in the forward acceleration of normal gait."

1997 - Gait and Posture, 5, 172-173

Siegel KL, Kepple TM, Caldwell GE "Improved agreement of foot segmental power and rate of energy change during gait: Inclusion of distal power terms and use of three-dimensional models."

1996 - Journal of Biomechanics 29(6):823-827

Traditional models used to calculate foot segmental power have yielded poor agreement between foot power and the rate of energy change during the stance phase of gait and limited the applicability of foot segmental power analyses to swing phase only. The purpose of this study was to improve the agreement of foot segemental power and rate of energy change by using more inclusive models to calculate foot segmental power and energy. The gait of 15 adult subjects was studied and models were used to calculate foot segmental power that included either the proximal terms only (Model P, the most common method in the literature) or both proximal and distal terms (Model PD, a mathematically complete model). Power and energy terms were computed in to ways, from sagittal plane vector components only (two-dimensional condition) and from complete three-dimensional components (three-dimensional condition). Results revealed that the more inclusive the model, the higher the agreement of foot power and rate of energy change. During stance phase, Model P produced poor agreement (rc = 0.108) for both two-dimensional and three-dimensional conditions, Model PD-2D yielded higher agreement (rc = 0.645), and Model PD-3D exhibited nearly perfect agreement (rc = 0.956). The advantages of a segmental power analysis include the ability to identify the mechanisms of energy transfer into and out of the foot during movement. The results of this study suggest that foot power analyses are valid when using Model PD-3D to describe foot function during locomotion.

Buczek FL, Kepple TM, Lohmann Siegel K., Stanhope SJ "Effect of one, three, and six degree-of-freedom modeling upon joint powers at the normal knee."

1994 - Proceedings of the Second World Congress on Biomechanics, 151

Kepple TM, Arnold AS, Stanhope SJ, Siegel KL "Measurement of musculoskeletal motion from surface landmarks: A three-dimensional computer graphics approach."

1994 - Journal of Biomechanics 27(3):365-371

Buczek FL, Kepple TM, Siegel KL, Stanhope SJ. "Translational and Rotational Joint Power Terms in a Six Degree-of-Freedom Model of the Normal Ankle Complex."

1994 - Journal of Biomechanics 27(12):1447-1457

Buczek F., Siegel K., Kepple T., Stanhope S. "Ground reaction force signal processing in joint power calculations."

1991 - Proceedings of the Seventh Annual East Coast Gait Laboratory Conference

Stanhope SJ, Kepple TM, McGuire DA, Roman NL. "A Kinematic-Based Technique for Event Time Determination During Gait."

1990 - Medical and Biological Engineering and Computing 28:355-360

Visual3D provides an automated determination of events within motion data. An event is defined as a user defined significant occurrence during data collections. Examples of events are: heel strike, mid- stance, foot off during gait, signals generated by analog device associated with bells, buzzers, lights, potentiometers and foot switches, and events based on kinematic data such as mid-swing or mid- stance.

Kepple T., Stanhope S. A "A Video based, six degree of freedom approach for analyzing human motion."

1989 - Proceedings of the Fifth Annual East Coast Gait Laboratories Conference

Kepple T., Stanhope S., Rich A. "The presentation and evaluation of a video based, six degree-of-freedom approach for analyzing human motion"

1988 - Proceedings of the Annual IEEE Engineering in Medicine and Biology Society

Antonsson EK "A three-dimensional kinematic acquisition and intersegmental dynamic analysis system for human motion. "

1982 - Ph.D dissertation, Massachusetts Institute of Technology.

NOTE: This was the seminal work that started Tom Kepple on the path of MOVE3D.

Uses or References to Visual3D (or Move3D):

Palmieri-Smith RM, Kreinbrink J, Ashton-Miller JA, and Wojtys EM "Association of Quadriceps and Hamstrings Cocontraction Patterns With Knee Joint Loading"

2009 - Journal of Athletic Training 2009;44(3):256–263

CONTEXT: Sex differences in neuromuscular control of the lower extremity have been identified as a potential cause for the greater incidence of anterior cruciate ligament (ACL) injuries in female athletes compared with male athletes. Women tend to land in greater knee valgus with higher abduction loads than men. Because knee abduction loads increase ACL strain, the inability to minimize these loads may lead to ACL failure. OBJECTIVE: To investigate the activation patterns of the quadriceps and hamstrings muscles with respect to the peak knee abduction moment. DESIGN: Cross-sectional study. SETTING: Neuromuscular research laboratory. PATIENTS OR OTHER PARTICIPANTS: Twenty-one recreationally active adults (11 women, 10 men). MAIN OUTCOME MEASURE(S): Volunteers performed 3 trials of a 100-cm forward hop. During the hop task, we recorded surface electromyographic data from the medial and lateral hamstrings and quadriceps and recorded lower extremity kinematics and kinetics. Lateral and medial quadriceps-to-hamstrings (QratioH) cocontraction indices, the ratio of medial-to-lateral QratioH cocontraction, normalized root mean square electromyographic data for medial and lateral quadriceps and hamstrings, and peak knee abduction moment were calculated and used in data analyses. RESULTS: Overall cocontraction was lower in women than in men, whereas activation was lower in the medial than in the lateral musculature in both sexes (P < .05). The medial QratioH cocontraction index (R(2) = 0.792) accounted for a significant portion of the variance in the peak knee abduction moment in women (P = .001). Women demonstrated less activation in the vastus medialis than in the vastus lateralis (P = .49) and less activation in the medial hamstrings than in the lateral hamstrings (P = .01). CONCLUSIONS: Medial-to-lateral QratioH cocontraction appears to be unbalanced in women, which may limit their ability to resist abduction loads. Because higher abduction loads increase strain on the ACL, restoring medial-to-lateral QratioH cocontraction balance in women may help reduce ACL injury risk.

Reference

Drewniak E, Jay G, Fleming B, Crisco J "Comparison of two methods for calculating the frictional properties of articular cartilage using a simple pendulum and intact mouse knee joints"

2009 - Journal of Biomechanics, Volume 42, Issue 12, Pages 1996-1999

In attempts to better understand the etiology of osteoarthritis, a debilitating joint disease that results in the degeneration of articular cartilage (AC) in synovial joints, researchers have focused on joint tribology, the study of joint friction, lubrication, and wear. Several different approaches have been used to investigate the frictional properties of articular cartilage. In this study, we examined two analysis methods for calculating the coefficient of friction (μ) using a simple pendulum system and BL6 murine knee joints (n=10) as the fulcrum. A Stanton linear decay model (Lin μ) and an exponential model that accounts for viscous damping (Exp μ) were fit to the decaying pendulum oscillations. Root mean square error (RMSE), asymptotic standard error (ASE), and coefficient of variation (CV) were calculated to evaluate the fit and measurement precision of each model. This investigation demonstrated that while Lin μ was more repeatable, based on CV (5.0% for Lin μ; 18% for Exp μ), Exp μ provided a better fitting model, based on RMSE (0.165° for Exp μ; 0.391° for Lin μ) and ASE (0.033 for Exp μ; 0.185 for Lin μ), and had a significantly lower coefficient of friction value (0.022±0.007 for Exp μ; 0.042±0.016 for Lin μ) (p=0.001). This study details the use of a simple pendulum for examining cartilage properties in situ that will have applications investigating cartilage mechanics in a variety of species. The Exp μ model provided a more accurate fit to the experimental data for predicting the frictional properties of intact joints in pendulum systems.

O'Connor K, Bottum MC "Differences in Cutting Knee Mechanics Based on Principal Components Analysis"

2009 - Medicine & Science in Sports & Exercise: April 2009 - Volume 41 - Issue 4 - pp 867-878

Purpose: The increased number of women participating in sports has led to a higher knee injury rate in women compared with men. Analysis of injury risk is limited to identification of discrete-dependent variables, but analysis of the entire waveform using principal components analysis (PCA) may provide greater insight. The purpose of this study was to examine gender differences in cutting knee mechanics using PCA and to compare these findings to those based on traditional discrete measures. Methods: Sixteen male and 17 female recreational athletes were recruited to perform unanticipated run and cutting tasks. Three-dimensional joint dynamics were recorded, and discrete variables were extracted. PCA analyses were also performed on the angle and moment waveforms in all three planes. The PCA used an eigenvalue analysis on the data covariance matrix. Gender differences in the principal component (PC) scores generated by the PCA were assessed using a MANOVA (P < 0.05). Results: On the basis of the discrete variables, flexion range of motion for females was less than for males. From the PCA analysis, females were less internally rotated during late stance and exhibited a relatively greater peak adduction moment that was not apparent in the original time series. This peak moment correlated with a greater abduction oscillation during early stance. There was also less variability for females in the sagittal and frontal plane moment PC. Conclusions: The PCA analysis did not significantly detect the decreased flexion, but PCA did reveal gender differences in movement patterns and variability that were not apparent in the discrete variables. The results of this study demonstrate the potential of PCA to provide deeper understand of movement dynamics that may help in detecting injury risk factors.

Merican AM, Amis AA "Iliotibial band tension affects patellofemoral and tibiofemoral kinematics"

2009 - Journal of Biomechanics Volume 42, Issue 10, 22 July 2009, Pages 1539-1546

The iliotibial band (ITB) has an important role in knee mechanics and tightness can cause patellofemoral maltracking. This study investigated the effects of increasing ITB tension on knee kinematics. Nine fresh-frozen cadaveric knees had the components of the quadriceps loaded with 175 N. A Polaris optical tracking system was used to acquire joint kinematics during extension from 100° to 0° flexion. This was repeated after the following ITB loads: 30, 60 and 90 N. There was no change with 30 N load for patellar translation. On average, at 60 and 90 N, the patella translated laterally by 0.8 and 1.4 mm in the mid flexion range compared to the ITB unloaded condition. The patella became more laterally tilted with increasing ITB loads by 0.7°, 1.2° and 1.5° for 30, 60 and 90 N, respectively. There were comparable increases in patellar lateral rotation (distal patella moves laterally) towards the end of the flexion cycle. Increased external rotation of the tibia occurred from early flexion onwards and was maximal between 60° and 75° flexion. The increase was 5.2°, 9.5° and 13° in this range for 30, 60 and 90 N, respectively. Increased tibial abduction with ITB loads was not observed. The combination of increased patellar lateral translation and tilt suggests increased lateral cartilage pressure. Additionally, the increased tibial external rotation would increase the Q angle. The clinical consequences and their relationship to lateral retinacular releases may be examined, now that the effects of a tight ITB are known.

Schmitt LC, Rudolph KS "Muscle stabilization strategies in people with medial knee osteoarthritis: The effect of instability"

2008 - Journal of Orthopaedic Research Journal of Orthopaedic Research Volume 26 Issue 9, Pages 1180 - 1185

The sensation of knee instability (shifting, buckling. and giving way) is common in people with medial knee osteoarthritis (OA). Its influence on knee stabilization strategies is unknown. This study investigated the influence of knee instability on muscle activation during walking when knee stability was challenged. Twenty people with medial knee OA participated and were grouped as OA Stable (OAS) (n = 10) and OA Unstable (OAU) (n = 10) based on self-reported knee instability during daily activities. Quadriceps strength, passive knee laxity, and varus alignment were assessed and related to knee instability and muscle cocontraction during walking when the support surface translated laterally. Few differences in knee joint kinematics between the groups were seen; however, there were pronounced differences in muscle activation. The OAU group used greater medial muscle cocontraction before, during, and following the lateral translation. Self-reported knee instability predicted medial muscle cocontraction, but medial laxity and limb alignment did not. The higher muscle cocontraction used by the OAU subjects appears to be an ineffective strategy to stabilize the knee. Instability and high cocontraction can be detrimental to joint integrity, and should be the focus of future research.

Goldberg EJ, Requejo PS, Fowler EG "The effect of direct measurement versus cadaver estimates of anthropometry in the calculation of joint moments during above-knee prosthetic gait in pediatrics"

2008 - Journal of Biomechanics 41 (2008) 695-800

Joint reaction forces, moments and powers are important in interpreting gait mechanics and compensatory strategies used by patients walking with above-knee prostheses. Segmental anthropometrics, required to calculate joint moments, are often estimated using data from cadaver studies. However, these values may not be accurate for patients following amputation as prostheses are composed of nonbiologic material. The purpose of this study was to compare joint moments using anthropometrics calculated from cadaver studies versus direct measurements of the residual limb and prosthesis for children with an above-knee amputation. Gait data were collected for four subjects with above-knee prostheses walking at preferred and fast speeds. Joint moments were computed using anthropometrics from cadaver studies and direct measurements for each subject. The difference between these two methods primarily affected the inertia couple (Ia term) and the inertial effect due to gravity, which comprised a greater percentage of the total joint moment during swing as compared to stance. Peak hip and knee flexor and extensor moments during swing were significantly greater when calculated using cadaver data (po0.05). These differences were greater while walking fast as compared to slow speeds. A significant difference was not found between these two methods for peak hip and knee moments during stance. A significant difference was found for peak ankle joint moments during stance, but the magnitude was not clinically important. These results support the use of direct measurements of anthropometry when examining above-knee prosthetic gait, particularly during swing.

Farrokhi S, Pollard CD, Souza RB, Chen YJ, Reischl S, Powers CM. "Trunk position influences the kinematics, kinetics, and muscle activity of the lead lower extremity during the forward lunge exercise."

2008 - J Orthop Sports Phys Ther. 2008 Jul;38(7):403-9. Epub 2008 Apr 15

STUDY DESIGN: Experimental laboratory study. OBJECTIVES: To examine how a change in trunk position influences the kinematics, kinetics, and muscle activity of the lead lower extremity during the forward lunge exercise. BACKGROUND: Altering the position of the trunk during the forward lunge exercise is thought to affect the muscular actions of the lead lower extremity. However, no studies have compared the biomechanical differences between the traditional forward lunge and its variations. METHODS AND MEASURES: Ten healthy adults (5 males, 5 females; mean age +/- SD, 26.7 +/- 3.2 years) participated. Lower extremity kinematics, kinetics, and surface electromyographic (EMG) data were obtained while subjects performed 3 lunge exercises: normal lunge with the trunk erect (NL), lunge with the trunk forward (LTF), and lunge with trunk extension (LTE). A 1-way analysis of variance with repeated measures was used to compare lower extremity kinematics, joint impulse (area under the moment-time curve), and normalized EMG (highest 1-second window of activity for selected lower extremity muscles) among the 3 lunge conditions. RESULTS: During the LTF condition, significant increases were noted in peak hip flexion angle, hip extensor and ankle plantar flexor impulse, as well as gluteus maximus and biceps femoris EMG (P<.015) when compared to the NL condition. During the LTE condition, a significant increase was noted in peak ankle dorsiflexion and a significant decrease was noted in peak hip flexion angle (P<.015) compared to the NL condition. CONCLUSIONS: Performing a lunge with the trunk forward increased the hip extensor impulse and the recruitment of the hip extensors. In contrast, performing a forward lunge with the trunk extended did not alter joint impulse or activation of the lower extremity musculature. LEVEL OF EVIDENCE: Therapy, level 5.

Siegel KL, Kepple TM, Stanhope SJ "A case study of gait compensations for hip muscle weakness in idiopathic inflammatory myopathy."

2007 - Clin Biomech (Bristol, Avon). 2007 Mar;22(3):319-26

BACKGROUND: The purpose of this case series was to quantify different strategies used to compensate in gait for hip muscle weakness. METHODS: An instrumented gait analysis was performed of three females diagnosed with idiopathic inflammatory myopathies and compared to a healthy unimpaired subject. Lower extremity joint moments obtained from the gait analysis were used to drive an induced acceleration model which determined each moment\\\'s contribution to upright support, forward progression, and hip joint acceleration. FINDINGS: Results showed that after midstance, the ankle plantar flexors normally provide upright support and forward progression while producing hip extension acceleration. In normal gait, the hip flexors eccentrically resist hip extension, but the hip flexor muscles of the impaired subjects (S1-3) were too weak to control extension. Instead S1-3 altered joint positions and muscle function to produce forward progression while minimizing hip extension acceleration. S1 increased knee flexion angle to decrease the hip extension effect of the ankle plantar flexors. S2 and S3 used either a knee flexor moment or gravity to produce forward progression, which had the advantage of accelerating the hip into flexion rather than extension, and decreased the demand on the hip flexors. INTERPRETATION: Results showed how gait compensations for hip muscle weakness can produce independent (i.e. successful) ambulation, although at a reduced speed as compared to normal gait. Knowledge of these successful strategies can assist the rehabilitation of patients with hip muscle weakness who are unable to ambulate and potentially be used to reduce their disability.

Ramsey DK, Briem K, Axe MJ, and Snyder-Mackler L "A Mechanical Theory for the Effectiveness of Bracing for Medial Compartment Osteoarthritis of the Knee."

2007 - The Journal of Bone and Joint Surgery (American) 89:2398-2407

Rudolph KS, Schmitt LC, and Lewek MD "Age-Related Changes in Strength, Joint Laxity, and Walking Patterns: Are They Related to Knee Osteoarthritis?"

2007 - PHYS THER, Vol. 87, No. 11, 1422-1432

Background and Purpose Aging is associated with musculoskeletal changes and altered walking patterns. These changes are common in people with knee osteoarthritis (OA) and may precipitate the development of OA. We examined age-related changes in musculoskeletal structures and walking patterns to better understand the relationship between aging and knee OA. Methods Forty-four individuals without OA (15 younger, 15 middle-aged, 14 older adults) and 15 individuals with medial knee OA participated. Knee laxity, quadriceps femoris muscle strength (force-generating capacity), and gait were assessed. Results Medial laxity was greater in the OA group, but there were no differences between the middle-aged and older control groups. Quadriceps femoris strength was less in the older control group and in the OA group. During the stance phase of walking, the OA group demonstrated less knee flexion and greater knee adduction, but there were no differences in knee motion among the control groups. During walking, the older control group exhibited greater quadriceps femoris muscle activity and the OA group used greater muscle co-contraction. Discussion and Conclusion Although weaker, the older control group did not use truncated motion or higher co-contraction. The maintenance of movement patterns that were similar to the subjects in the young control group may have helped to prevent development of knee OA. Further investigation is warranted regarding age-related musculoskeletal changes and their influence on the development of knee OA.

Lee SJ, and Hidler J "Biomechanics of Overground Versus Treadmill Walking In Healthy Individuals."

2007 - Journal of Applied Physiology

The goal of this study was to compare treadmill walking with overground walking in healthy subjects with no known gait disorders. Nineteen subjects were tested, where each subject walked on a split-belt instrumented treadmill as well as over a smooth, flat surface. Comparisons between walking conditions were made for temporal gait parameters such as step length and cadence, leg kinematics, joint moments and powers, and muscle activity. Overall, very few differences were found in temporal gait parameters or leg kinematics between treadmill and overground walking. Conversely, sagittal plane joint moments were found to be quite different, where during treadmill walking trials, subjects demonstrated less dorsiflexor moments, less knee extensor moments, and greater hip extensor moments. Joint powers in the sagittal plane were found to be similar at the ankle but quite different at the knee and hip joints. Differences in muscle activity were observed between the two walking modalities, particularly in the tibialis anterior throughout stance, and in the hamstrings, vastus medialis and adductor longus during swing. While differences were observed in muscle activation patterns, joint moments and joint powers between the two walking modalities, the overall patterns in these behaviors were quite similar. From a therapeutic perspective, this suggests that training individuals with neurological injuries on a treadmill appears to be justified.

Tokuno CD, Carpenter MG, Thorstensson A, Garland SJ, and Cresswell AG "Control of the triceps surae during the postural sway of quiet standing."

2007 - Acta Physiologica, Volume 191 Issue 3 Page 229-236

Segers V, Aerts P, Lenoir M, De Clercq, D "Dynamics of the body centre of mass during actual acceleration across transition speed."

2007 - Journal Exp Biol 310, 578-585

Judged by whole body dynamics, walking and running in humans clearly differ. When walking, potential and kinetic energy fluctuate out-of-phase and energy is partially recovered in a pendulum-like fashion. In contrast, running involves in-phase fluctuations of the mechanical energy components of the body centre of mass, allowing elastic energy recovery. We show that, when constantly accelerating across the transition speed, humans make the switch from walking to running abruptly in one single step. In this step, active mechanical energy input triples the normal step-by-step energy increment needed to power the imposed constant acceleration. This extra energy is needed to launch the body into the flight phase of the first running step and to bring the trunk into its more inclined orientation during running. Locomotor cycles immediately proceed with the typical in-phase fluctuations of kinetic and potential energy. As a result, the pendular energy transfer drops in one step from 43% to 5%. Kinematically, the transition step is achieved by landing with the knee and hip significantly more flexed compared to the previous walking steps. Flexion in these joints continues during the first half of stance, thus bringing the centre of mass to its deepest position halfway through stance phase to allow for the necessary extension to initiate the running gait. From this point of view, the altered landing conditions seem to constitute the actual transition.

Ramsey DK, Snyder-Mackler L, Lewek M, Newcomb W, Rudolph KS. "Effect of anatomic realignment on muscle function during gait in patients with medial compartment knee osteoarthritis."

2007 - rthritis Care & Research. Volume 57, Issue 3 , Pages 389 - 397

Willems, Tine Mariek, Witvrouw, Erik, De Cock, Anneleen, De Clercq, Dirk "Gait-Related Risk Factors for Exercise-Related Lower-Leg Pain during Shod Running."

2007 - Medicine & Science in Sports & Exercise. 39(2):330-339

Domingo A, Sawicki GS, Ferris DP. "Kinematics and muscle activity of individuals with incomplete spinal cord injury during treadmill stepping with and without manual assistance."

2007 - Journal of Neuroengineering and Rehabilitation 4:32

Background Treadmill training with bodyweight support and manual assistance improves walking ability of patients with neurological injury. The purpose of this study was to determine how manual assistance changes muscle activation and kinematic patterns during treadmill training in individuals with incomplete spinal cord injury. Methods We tested six volunteers with incomplete spinal cord injury and six volunteers with intact nervous systems. Subjects with spinal cord injury walked on a treadmill at six speeds (0.18–1.07 m/s) with body weight support with and without manual assistance. Healthy subjects walked at the same speeds only with body weight support. We measured electromyographic (EMG) and kinematics in the lower extremities and calculated EMG root mean square (RMS) amplitudes and joint excursions. We performed cross-correlation analyses to compare EMG and kinematic profiles. Results Normalized muscle activation amplitudes and profiles in subjects with spinal cord injury were similar for stepping with and without manual assistance (ANOVA, p > 0.05). Muscle activation amplitudes increased with increasing speed (ANOVA, p < 0.05). When comparing spinal cord injury subject EMG data to control subject EMG data, neither the condition with manual assistance nor the condition without manual assistance showed a greater similarity to the control subject data, except for vastus lateralis. The shape and timing of EMG patterns in subjects with spinal cord injury became less similar to controls at faster speeds, especially when walking without manual assistance (ANOVA, p < 0.05). There were no consistent changes in kinematic profiles across spinal cord injury subjects when they were given manual assistance. Knee joint excursion was ~5 degrees greater with manual assistance during swing (ANOVA, p < 0.05). Hip and ankle joint excursions were both ~3 degrees lower with manual assistance during stance (ANOVA, p < 0.05). Conclusion Providing manual assistance does not lower EMG amplitudes or alter muscle activation profiles in relatively higher functioning spinal cord injury subjects. One advantage of manual assistance is that it allows spinal cord injury subjects to walk at faster speeds than they could without assistance. Concerns that manual assistance will promote passivity in subjects are unsupported by our findings.

Reference

Gordon KE and Ferris DP "Learning to walk with a robotic ankle exoskeleton"

2007 - Journal of Biomechanics, 40:2636-2644

We used a lower limb robotic exoskeleton controlled by the wearer's muscle activity to study human locomotor adaptation to disrupted muscular coordination. Ten healthy subjects walked while wearing a pneumatically powered ankle exoskeleton on one limb that effectively increased plantar flexor strength of the soleus muscle. Soleus electromyography amplitude controlled plantar flexion assistance from the exoskeleton in real time. We hypothesized that subjects' gait kinematics would be initially distorted by the added exoskeleton power, but that subjects would reduce soleus muscle recruitment with practice to return to gait kinematics more similar to normal. We also examined the ability of subjects to recall their adapted motor pattern for exoskeleton walking by testing subjects on two separate sessions, 3 days apart. The mechanical power added by the exoskeleton greatly perturbed ankle joint movements at first, causing subjects to walk with significantly increased plantar flexion during stance. With practice, subjects reduced soleus recruitment by approximately 35% and learned to use the exoskeleton to perform almost exclusively positive work about the ankle. Subjects demonstrated the ability to retain the adapted locomotor pattern between testing sessions as evidenced by similar muscle activity, kinematic and kinetic patterns between the end of the first test day and the beginning of the second. These results demonstrate that robotic exoskeletons controlled by muscle activity could be useful tools for testing neural mechanisms of human locomotor adaptation.

Palmieri-Smith RM, Kreinbrink J, Ashton-Miller JA, and Wojtys EM "Quadriceps Inhibition Induced by an Experimental Knee Joint Effusion Affects Knee Joint Mechanics During a Single-Legged Drop Landing."

2007 - Am J Sports Med. 35: 1269-1275

Background: Arthrogenic quadriceps muscle inhibition accompanies knee joint effusion and impedes rehabilitation after knee joint injury. Hypothesis: We hypothesized that an experimentally induced knee joint effusion would cause arthrogenic quadriceps muscle inhibition and lead to increased ground reaction forces, as well as sagittal plane knee angles and moments, during a single-legged drop landing. Study Design: Controlled laboratory study. Methods: Nine subjects (4 women and 5 men) underwent 4 conditions (no effusion, lidocaine injection, “low” effusion [30 mL], and “high” effusion [60 mL]) and then performed a single-legged drop landing. Lower extremity muscle activity, peak sagittal plane knee flexion angles, net sagittal plane knee moments, and peak ground reaction forces were measured. Results: Vastus medialis and lateralis activity were decreased during the low and high effusion conditions (P < .05). However, increases in peak ground reaction forces and decreases in peak knee flexion angle and net knee extension moments occurred only during the high effusion condition (P < .05). Conclusions: Knee joint effusion induced quadriceps inhibition and altered knee joint mechanics during a landing task. Subjects landed with larger ground reaction forces and in greater knee extension, thereby suggesting that more force will be transferred to the knee joint and its passive restraints when quadriceps inhibition is present. Clinical Relevance: Knee joint effusion results in arthrogenic quadriceps muscle inhibition, increasing loading about the knee that may potentially increase the risk of future knee joint trauma or degeneration.

Ford F, Myer GD, Hewett TE "Reliability of Landing 3D Motion Analysis: Implications for Longitudinal Analyses."

2007 - Medicine & Science in Sports & Exercise. 39(11):2021-2028

PURPOSE: Biomechanical measures quantified during dynamic tasks with coupled epidemiological data in longitudinal experimental designs may be useful to determine which mechanisms underlie injury risk in young athletes. A key component is the ability to reliably measure biomechanical variables between testing sessions. The purpose was to determine the reliability of three-dimensional (3D) lower-extremity kinematic and kinetic variables during landing in young athletes measured within a session and between two sessions 7 wk apart. METHODS: Lower-extremity kinetics and kinematics were quantified during a drop vertical jump. Coefficient of multiple correlations (CMC), intraclass correlation coefficients (ICC (3, k), ICC (3, 1)), and typical error (TE) analyses were used to examine within- and between-session reliability. RESULTS: There were no differences in within-session reliability for peak angular rotations between planes with all discrete variables combined (sagittal ICC > or = 0.933, frontal ICC > or = 0.955, transverse ICC > or = 0.934). Similarly, the between-session reliability of kinematic measures were not different between the three planes of motion but were lower than the within-session ICC. The within- and between-session reliability of discrete joint moment variables were excellent for all sagittal (within ICC > or = 0.925, between ICC > or = 0.800) and frontal plane moment measures (within ICC > or = 0.778, between ICC > or = 0.748). CMC analysis revealed similar averaged within-session (CMC = 0.830 +/- 0.119) and between-session (CMC = 0.823 +/- 0.124) waveform comparisons. CONCLUSION: The majority of the kinematic and kinetic variables in young athletes during landing have excellent to good reliability. The ability to reliably quantify lower-extremity biomechanical variables of young athletes during dynamic tasks over extended intervals may aid in identifying potential mechanisms related to injury risk factors.

Wheat JS, Vernon T, Milner CE "The measurement of upper body alignment during the golf drive."

2007 - ournal of Sports Sciences, 25(7):749-755

Khan WS, Nokes L, Jones RK, Johnson DS "The relationship of the angle of immobilisation of the knee to the force applied to the extensor mechanism when partially weight-bearing. A Gait-Analysis Study in Normal Volunteers."

2007 - Journal of Bone and Joint Surgery - British Volume, Vol 89-B, Issue 7, 911-914

Chow JY, Davids K, Button C, Koh M "Variation in Coordination of a Discrete Multiarticular Action as a Function of Skill Level."

2007 - Journal of Motor Behavior, Volume 39, Number 6, 463 - 479

Mizner RL, Snyder-Mackler L "Altered loading during walking and sit-to-stand is affected by quadriceps weakness after total knee arthroplasty."

2006 - Journal of Orthopaedic Research Volume 23, Issue 5 , Pages 1083 - 1090

Total knee arthroplasty (TKA) successfully reduces pain, but has not achieved comparable improvements in function. We hypothesized that quadriceps strength affects performance by altering loading and movement patterns during functional tasks. METHODS: Fourteen subjects with isolated, unilateral TKA were tested three months after surgery. Quadriceps strength was assessed isometrically and kinematics, kinetics, and EMG were collected during level walking and sit-to-stand (STS). Function was assessed using the timed up and go test (TUG), stair climbing test (SCT), and the 6 min walk test (6MW). RESULTS: Functional performance was significantly related to the quadriceps strength of both legs, but was more strongly related to the uninvolved strength (involved rho=-0.43 with TUG; -0.65 with SCT; 0.64 with 6MW) (uninvolved rho=-0.63 with TUG; -0.68 with SCT; 0.77 with 6MW). During STS, subjects shifted weight away from the operated limb

Milner CE, Ferber R, Pollard CD, Hamill J, Davis IS "Biomechanical Factors Associated with Tibial Stress Fracture in Female Runners"

2006 - Med. Sci. Sports Exerc., Vol. 38, No. 2, pp. 323–328, 2006

MILNER, C. E., R. FERBER, C. D. POLLARD, J. HAMILL, and I. S. DAVIS. Biomechanical Factors Associated with Tibial Stress Fracture in Female Runners. Med. Sci. Sports Exerc., Vol. 38, No. 2, pp. 323–328, 2006. Purpose: Tibial stress fractures (TSF) are among the most serious running injuries, typically requiring 6–8 wk for recovery. This cross-sectional study was conducted to determine whether differences in structure and running mechanics exist between trained distance runners with a history of prior TSF and those who have never sustained a fracture. Methods: Female runners with a rearfoot strike pattern, aged between 18 and 45 yr and running at least 32 kmIwkj1, were recruited for this study. Participants in the study were 20 subjects with a history of TSF and 20 ageand mileage-matched control subjects with no previous lower extremity bony injuries. Kinematic and kinetic data were collected during overground running at 3.7 mIsj1 using a six-camera motion capture system, force platform, and accelerometer. Variables of interest were vertical impact peak, instantaneous and average vertical loading rates, instantaneous and average loading rates during braking, knee flexion excursion, ankle and knee stiffness, and peak tibial shock. Tibial varum was measured in standing. Tibial area moment of inertia was calculated from tibial x-ray studies for a subset of runners. Results: The TSF group had significantly greater instantaneous and average vertical loading rates and tibial shock than the control group. The magnitude of tibial shock predicted group membership successfully in 70% of cases. Conclusion: These data indicate that a history of TSF in runners is associated with increases in dynamic loading-related variables. Key Words: GROUND REACTION FORCES, KINEMATICS, TIBIAL SHOCK, AREA MOMENT OF INERTIA

MacLean C, McClay Davis I, and Hamill J "Influence of a custom foot orthotic intervention on lower extremity dynamics in healthy runners."

2006 - Clinical Biomechanics, Volume 21, Issue 6, Pages 623-630

Butler RJ, Davis IS, and Hamill J "Interaction of arch type and footwear on running mechanics."

2006 - American Journal of Sports Medicine 34, 1998-2005

BACKGROUND: Running shoes are designed to accommodate various arch types to reduce the risk of lower extremity injuries sustained during running. Yet little is known about the biomechanical changes of running in the recommended footwear that may allow for a reduction in injuries. PURPOSE: To evaluate the effects of motion control and cushion trainer shoes on running mechanics in low- and high-arched runners. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty high-arched and 20 low-arched recreational runners (>10 miles per week) were recruited for the study. Three-dimensional kinematic and kinetics were collected as subjects ran at 3.5 ms(-1) +/- 5% along a 25-m runway. The motion control shoe evaluated was the New Balance 1122, and the cushioning shoe evaluated was the New Balance 1022. Repeated-measures analyses of variance were used to determine if low- and high-arched runners responded differently to motion control and cushion trainer shoes. RESULTS: A significant interaction was observed in the instantaneous loading rate such that the low-arched runners had a lower instantaneous loading rate in the motion control condition, and the high-arched runners had a lower instantaneous loading rate in the cushion trainer condition. Significant main effects for shoe were observed for peak positive tibial acceleration, peak-to-peak tibial acceleration, mean loading rate, peak eversion, and eversion excursion. CONCLUSION: These results suggest that motion control shoes control rearfoot motion better than do cushion trainer shoes. In addition, cushion trainer shoes attenuate shock better than motion control shoes do. However, with the exception of instantaneous loading rate, these benefits do not differ between arch type. CLINICAL RELEVANCE: Running footwear recommendations should be based on an individual's running mechanics. If a mechanical analysis is not available, footwear recommendations can be based empirically on the individual's arch type.

Whatling GM, Holt CA, Jones L, Madete JK, Dabke H, Alderman PM and Roberts P "Investigating the effects of surgical approach on total hip arthroplasty recovery using 3D gait analysis."

2006 - Ninth international symposium on teh 3D analysis of Human Movement

Gordon KE, Sawicki GS and Ferris DP "Mechanical performance of artificial pneumatic muscles to power an ankle-foot orthosis."

2006 - Journal of Biomechanics, 39:1832-1841

Ferris DP, Bohra ZA, Lukos JR and Kinnaird CR "Neuromechanical adaptation to hopping with an elastic ankle-foot orthosis."

2006 - Journal of Applied Physiology, 100:163-170

Buczek F, Cooney K, Walker M, Rainbow M, Concha M, Sanders JO "Performance of an inverted pendulum model directly applied to normal human gait."

2006 - Clinical Biomechanics, Volume 21, Issue 3, Pages 288-296

Turner DE, Helliwell PS, Emery P, and Woodburn J "The impact of rheumatoid arthritis on foot function in the early stages of disease: a clinical case series. BioMed Center Musculoskeletal Disorders."

2006 - BMC Musculoskeletal Disorders 2006, 7:102

Reference

Stensdotter AK, Holmgren C, Dal?n T, H?ger-Ross C "The role of M. popliteus in unpredictable and in self-initiated balance provocations."

2006 - Journal of Orthopaedic Research, Volume 24, Issue 3 , Pages 524 - 530

Turner DE, Davys HJ & Woodburn J "Foot function following forefoot reconstruction in rheumatoid arthritis."

2005 - Australasian Journal of Podiatric Medicine; Vol 39, No.4 : 83-89

Pollard CD, McClay Davis I, Hamill J "Influence of gender on hip and knee mechanics during a randomly cued cutting maneuver"

2004 - Clinical Biomechanics, 19, 1022-1031

Siegel, KL, Kepple, TM, & Stanhope SJ "Joint moment control of mechanical energy flow during normal gait."

2004 - Gait and Posture, 19, 69-75

Woodburn J, Nelson KM, Siegel KL, Kepple TM, Gerber LH "Multisegment Foot Motion During Gait: Proof of Concept in Rheumatoid Arthritis."

2004 - The Journal of Rheumatology 31:10

OBJECTIVE: To test a multisegment foot model for kinematic analysis during barefoot walking in patients with well established rheumatoid arthritis (RA) and foot impairments. METHODS: Five healthy adult subjects and 11 RA patients with advanced disease were studied. Foot impairments were assessed using standardized outcomes and clinical examination techniques. A 6-camera 60 Hz video-based motion analysis system was used to measure motion of the shank, rearfoot, forefoot, and hallux segments and the vertical displacement of the navicular. Face validity and estimates of repeatability were determined. Motion patterns were calculated and comparisons were made between healthy subjects and patients with RA. Relationships between clinical impairment and abnormal motion were determined through inspection of individual RA cases. RESULTS: Across the motion variables, the within-day and between-day coefficient of multiple correlation values ranged from 0.677 to 0.982 for the healthy subjects and 0.830 to 0.981 for RA patients. Based on previous studies, motion parameters for the healthy subjects showed excellent face validity. In RA patients, there was reduced range of motion across all segments and all planes of motion, which was consistent with joint stiffness. In the RA patients, rearfoot motion was shifted towards eversion and external rotation and peak values for these variables were increased, on average, by 7 degrees and 11 degrees, respectively. Forefoot range of motion was reduced in all 3 planes (between 31% and 53%), but the maximum and minimum angles were comparable to normal. The navicular height, during full foot contact, was on average 3 mm lower in the RA patients in comparison to normal. The hallux was less extended in the RA subjects in comparison to normal (21 degrees vs 33 degrees) during the terminal stance phase. Individual cases showed abnormal patterns of motion consistent with their clinical impairments, especially those with predominant forefoot pain or pes planovalgus. CONCLUSION: In RA, multisegment foot models may provide a more complete description of foot motion abnormalities where pathology presents at multiple joints, leading to complex and varied patterns of impairment. This technique may be useful to evaluate functional changes in the foot and to help plan and assess logical, structurally based corrective interventions.

Manal K, Stanhope SJ "A novel method for displaying gait and clinical movement analysis data"

2003 - Gait and Posture, Volume 20, Issue 2, Pages 222-226

Plotting kinematic and kinetic data of a patient’s movement patterns relative to normative values (i.e., mean and ±1 S.D.) is a common method used by clinicians to visually assess deviations and interpret the patient’s gait analysis data. This method of data interpretation is often time consuming and complex, especially when the process requires the inspection of a plethora of line graphs for numerous variables that are displayed across several report pages. In this paper we propose an alternate method for displaying movement pattern deviations relative to normative data by color-coding the magnitude and the direction of the deviation. An advantage of this approach is that a single page summary of all the deviation magnitudes can be displayed simultaneously, in a manner that is concise, visually effective and reduces complexity. The purpose of this paper is to describe the algorithmic development of the color-coding method.

Rainbow M, Buczek FL, Cooney KM, Walker MR, Sanders JO "DIFFERENCES BETWEEN VICON CLINICAL MANAGER AND VISUAL3D"

2003 - Abstracts of the American Society of Biomechanics

When switching biomechanical modeling software it is useful to note key differences between platforms. When using a given model like Helen Hayes, it is important that clinical decisions remain unaffected by software platform changes. This study showed no statistical dfiferenc between the Helen Hayes modeling in VCM and Visual3D for 16 out of 20 variables key to our gait analysis

Reference

Ferber R, McClay Davis I, Williams DS "Gender differences in lower extremity mechanics durin runnings"

2003 - Clinical Biomechanics 18: 350-357

Manal K, McLay I, Galinat B, Stanhope SJ "The accuracy of estimating proximal tibial translation during natural cadence walking: bone vs. skin mounted targets"

2003 - Clinical Biomechanics. 18, 126-131

Ferber R, McLay Davis I, Williams DS, Laughton C. "A comparison of within- and between-day reliability of discrete 3D lower extremity variables in runners."

2002 - Journal of Orthopedic Research 20: 1139-1145

It is important to understand the day-to-day variability that is attributed to repositioning of markers especially when assessing a treatment effect or response over time. While previous studies have reported reliability of waveform patterns, none have assessed the repeatability of discrete points such as peak angles, velocities and angular excursions which are often used when making statistical and clinical comparisons. The purpose of this study was to compare the within- and between-day variability of discrete kinematic, kinetic, and ground reaction force (GRF) data collected during running. Comparisons for 20 recreational runners were evaluated for within- and between-day reliability of discrete 3D kinematic, kinetic, and GRF variables. The results indicated that within-day comparisons were more reliable than between-day. Joint angular velocity and angular excursion values were more reliable between-days as compared to absolute peak angle measures and may be more useful in interpreting changes in treatment over time. Between-day kinematic and kinetic sagittal plane values were more reliable than secondary plane values. Reliability of GRF data was greater than kinematic and kinetic data for between-day comparisons.

Manal K, McLay I, Richards J, Galinat B, Stanhope SJ "Knee moment profiles during walking: errors due to soft tissue movement of the shank and the influence of the reference coordinate system"

2002 - Gait and Posture. 15, 10-17

Rudolf KS, Axe MJ, Buchanan TS, Scholz JP, Snyder-Mackler L "Dynamic stability in the anterior cruciate ligament deficient knee"

2001 - Knee Surg. Sprots Traumatol, Arthrosc 9: 62-71

Some individuals can stabilize their knees following anterior cruciate ligament rupture even during activities involving cutting and pivoting (copers), others have instability with daily activities (non-copers). Movement and muscle activation patterns of 11 copers, ten non-copers and ten uninjured subjects were studied during walking and jogging. Results indicate that distinct gait adaptations appeared primarily in the non-copers. Copers used joint ranges of motion, moments and muscle activation patterns similar to uninjured subjects. Non-copers reduced their knee motion, and external knee flexion moments that correlated well with quadriceps strength. Non-copers also achieved peak hamstring activity later in the weight acceptance phase and used a strategy involving more generalized co-contraction. Both copers and non-copers had high levels of quadriceps femoris muscle activity. The reduced knee moment in the involved limbs of the non-copers did not represent "quadriceps avoidance" but rather represented a strategy of general co-contraction with a greater relative contribution from the hamstring muscles.

Kepple TM, Stanhope SJ "Move3D Software."in Biomechanics and Neural Control of Posture and Movement"

2000 - (Winters and Crago Editors)

Gatev P, Thomas S, Kepple TM, & Hallett M "Feedforward ankle strategy of balance during quiet stance in adults"

1999 - Journal of Physiology,514.3, 915-928

1. We studied quiet stance investigating strategies for maintaining balance. Normal subjects stood with natural stance and with feet together, with eyes open or closed. Kinematic, kinetic and EMG data were evaluated and cross-correlated. 2. Cross-correlation analysis revealed a high, positive, zero-phased correlation between anteroposterior motions of the centre of gravity (COG) and centre of pressure (COP), head and COG, and between linear motions of the shoulder and knee in both sagittal and frontal planes. There was a moderate, negative, zero-phased correlation between the anteroposterior motion of COP and ankle angular motion. 3. Narrow stance width increased ankle angular motion, hip angular motion, mediolateral sway of the COG, and the correlation between linear motions of the shoulder and knee in the frontal plane. Correlations between COG and COP and linear motions of the shoulder and knee in the sagittal plane were decreased. The correlation between the hip angular sway in the sagittal and frontal planes was dependent on interaction between support and vision. 4. Low, significant positive correlations with time lags of the maximum of cross-correlation of 250-300 ms were found between the EMG activity of the lateral gastrocnemius muscle and anteroposterior motions of the COG and COP during normal stance. Narrow stance width decreased both correlations whereas absence of vision increased the correlation with COP. 5. Ankle mechanisms dominate during normal stance especially in the sagittal plane. Narrow stance width decreased the role of the ankle and increased the role of hip mechanisms in the sagittal plane, while in the frontal plane both increased. 6. The modulation pattern of the lateral gastrocnemius muscle suggests a central program of control of the ankle joint stiffness working to predict the loading pattern.

Holden JP, Stanhope SJ. "The Effect of Variation in Knee Center Location Estimates on Net Knee Joint Moments."

1998 - Gait and Posture 7, 1-6

Kepple, TMSiegel, KL, , & Stanhope SJ "Relative contributions of the lower extremity joint moments to forward progression and support during gait"

1997 - Gait and Posture, 6, 1-8

Kepple T. "MOVE3D - Software for analyzing human motion."

1991 - IEEE 1991 Future Directions Workshop, 106-109

Foot studies or research papers:

Milner CE, Hamill J, Davis IS "Distinct hip and rearfoot kinematics in female runners with a history of tibial stress fracture"

2010 - J Orthop Sports Phys Ther. 2010 Feb;40(2):59-66.

STUDY DESIGN: Cross-sectional controlled laboratory study. OBJECTIVES: To investigate the kinematics of the hip, knee, and rearfoot in the frontal and transverse planes in female distance runners with a history of tibial stress fracture. BACKGROUND: Tibial stress fractures are a common overuse injury in runners, accounting for up to half of all stress fractures. Abnormal kinematics of the lower extremity may contribute to abnormal musculoskeletal load distributions, leading to an increased risk of stress fractures. METHODS: Thirty female runners with a history of tibial stress fracture were compared to 30 age-matched and weekly-running-distance-matched control subjects with no previous lower extremity bony injuries. Kinematic and kinetic data were collected using a motion capture system and a force platform, respectively, as subjects ran in the laboratory. Selected variables of interest were compared between the groups using a multivariate analysis of variance (MANOVA). RESULTS: Peak hip adduction and peak rearfoot eversion angles were greater in the stress fracture group compared to the control group. Peak knee adduction and knee internal rotation angles and all joint angles at impact peak were similar between the groups. CONCLUSION: Runners with a previous tibial stress fracture exhibited greater peak hip adduction and rearfoot eversion angles during the stance phase of running compared to healthy controls. A consequence of these mechanics may be altered load distribution within the lower extremity, predisposing individuals to stress fracture.

Reference

Pohl MB, Hamill J, Davis IS. "Biomechanical and anatomic factors associated with a history of plantar fasciitis in female runners."

2009 - Clin J Sport Med. 2009 Sep;19(5):372-6.Click here to read

OBJECTIVE: To compare selected structural and biomechanical factors between female runners with a history of plantar fasciitis and healthy control subjects. DESIGN: Cross-sectional. SETTING: University of Delaware Motion Analysis Laboratory, Newark, Delaware; and University of Massachusetts Biomechanics Laboratory, Amherst, Massachusetts. PARTICIPANTS: Twenty-five female runners with a history of plantar fasciitis were recruited for this study. A group of 25 age- and mileage-matched runners with no history of plantar fasciitis served as control subjects. INTERVENTIONS: The independent variable was whether or not subjects had a history of plantar fasciitis. MAIN OUTCOME MEASURES: Subjects ran overground while kinematic and kinetic data were recorded using a motion capture system and force plate. Rearfoot kinematic variables of interest included peak dorsiflexion, peak eversion, time to peak eversion along with eversion excursion. Vertical ground reaction force variables included impact peak and the maximum instantaneous load rate. Structural measures were taken for calcaneal valgus and arch index during standing and passive ankle dorsiflexion range of motion. RESULTS: A significantly greater maximum instantaneous load rate was found in the plantar fasciitis group along with an increased ankle dorsiflexion range of motion compared with the control group. The plantar fasciitis group had a lower arch index compared with control subjects, but calcaneal valgus was similar between groups. No differences in rearfoot kinematics were found between groups. CONCLUSION: These data indicate that a history of plantar fasciitis in runners may be associated with greater vertical ground reaction force load rates and a lower medial longitudinal arch of the foot.

Maclean CL, Davis IS, Hamill J. "Influence of running shoe midsole composition and custom foot orthotic intervention on lower extremity dynamics during running."

2009 - J Appl Biomech. 2009 Feb;25(1):54-63.

The purpose of this study was to analyze the influence of varying running shoe midsole composition on lower extremity dynamics with and without a custom foot orthotic intervention. Three-dimensional dynamics were collected on 12 female runners who had completed 6 weeks of custom foot orthotic therapy. Participants completed running trials in 3 running shoe midsole conditions-with and without a custom foot orthotic intervention. Results from the current study revealed that only maximum rearfoot eversion velocity was influenced by the midsole durometer of the shoe. Maximum rearfoot eversion velocity was significantly decreased for the hard shoe compared with the soft shoe. However, the orthotic intervention in the footwear led to significant decreases in several dynamic variables. The results suggest that the major component influencing the rearfoot dynamics was the orthotic device and not the shoe composition. In addition, data suggest that the foot orthoses appear to compensate for the lesser shoe stability enabling it to function in a way similar to that of a shoe of greater stability.

Gordon KE, Sawicki GS and Ferris DP "Mechanical performance of artificial pneumatic muscles to power an ankle-foot orthosis."

2006 - Journal of Biomechanics, 39:1832-1841

Ferris DP, Bohra ZA, Lukos JR and Kinnaird CR "Neuromechanical adaptation to hopping with an elastic ankle-foot orthosis."

2006 - Journal of Applied Physiology, 100:163-170

Back or spine studies:

Seay J, Selbie WS, Hamill J. "In vivo lumbo-sacral forces and moments during constant speed running at different stride lengths."

2008 - J Sports Sci. 2008 Nov 6:1-11.

The aim of this study was to introduce a Newton-Euler inverse dynamics model that included reaction force and moment estimation at the lumbo-sacral (L5-S1) and thoraco-lumbar (T12-L1) joints. Data were collected while participants ran over ground at 3.8 m . s(-1) at three different stride lengths: preferred stride length, 20% greater than preferred, and 20% less than preferred. Inputs to the model were ground reaction forces, bilateral lower extremity and pelvis kinematics and inertial parameters, kinematics of the lumbar spine and thorax and inertial parameters of the lumbar segment. Repeated measures ANOVA were performed on the lower extremity sagittal kinematics and kinetics, including L5-S1 and T12-L1 three-dimensional joint angles, reaction forces and moments at touchdown and peak values during impact phase across the three stride conditions. Results indicated that L5-S1 and T12-L1 vertical reaction forces at touchdown and during the impact portion of the support phase increased significantly as stride length increased (P < 0.001), as did peak sagittal L5-S1 moments during impact (P = 0.018). Additionally, the transverse T12-L1 joint moment increased as running speed increased (P = 0.006). We concluded from our findings that our model was sensitive to our perturbations in healthy runners, and may prove useful in future mechanistic studies of L5-S1 mechanics.

Biomechanics - kinematics, kinetics, methods, algorithms, modeling:

Ferber R, Noehren B, Hamill J, Davis IS. "Competitive female runners with a history of iliotibial band syndrome demonstrate atypical hip and knee kinematics."

2010 - J Orthop Sports Phys Ther. 2010 Feb;40(2):52-8.

STUDY DESIGN: Cross-sectional experimental laboratory study. OBJECTIVE: To examine differences in running mechanics between runners who had previously sustained iliotibial band syndrome (ITBS) and runners with no knee-related running injuries. BACKGROUND: ITBS is the second leading cause of knee pain in runners and the most common cause of lateral knee pain. Despite its prevalence, few biomechanical studies have been conducted to better understand its aetiology. Because the iliotibial band has both femoral and tibial attachments, it is possible that atypical hip and foot mechanics could result in the development of ITBS. METHODS: The running mechanics of 35 females who had previously sustained ITBS were compared to 35 healthy age-matched and running distance-matched healthy females. Comparisons of hip, knee, and ankle 3-dimensional kinematics and internal moments during the stance phase of running gait were measured. RESULTS: The ITBS group exhibited significantly greater peak rearfoot invertor moment, peak knee internal rotation angle, and peak hip adduction angle compared to controls. No significant differences in peak rearfoot eversion angle, peak knee flexion angle, peak knee external rotator moment, or peak hip abductor moments were observed between groups. CONCLUSION: Females with a previous history of ITBS demonstrate a kinematic profile that is suggestive of increased stress on the iliotibial band. These results were generally similar to those reported for a prospective study conducted within the same laboratory environment.

Reference

Orishimo KF, Kremenic IJ, Pappas E, Hagins M, Liederbach M. "Comparison of landing biomechanics between male and female professional dancers. "

2009 - Am J Sports Med. 2009 Nov;37(11):2187-93. Epub 2009 Jun 26.

BACKGROUND: The incidence of anterior cruciate ligament injuries among dancers is much lower than that among team sport athletes and no clear gender disparity has been reported in the dance population. Although numerous studies have observed differences in lower extremity landing biomechanics between male and female athletes, there is currently little research examining the landing biomechanics of male and female dancers. Comparing landing biomechanics within this population may help explain the lower overall anterior cruciate ligament injury rates and the lack of gender disparity. HYPOTHESIS: Due to the fact that dancers receive jump-specific and balance-specific training from a very young age, we hypothesized that there would be no gender differences in drop-landing biomechanics in professional dancers. STUDY DESIGN: Controlled laboratory study. METHODS: Kinematics and ground-reaction forces were recorded as 33 professional modern and ballet dancers (12 men and 21 women) performed single-legged drop landings from a 30-cm platform. Joint kinematics and kinetics were compared between genders. RESULTS: No gender differences in joint kinematics or kinetics were found during landings (multivariate analysis of variance: P = .490 and P = .175, respectively). A significant relationship was found between the age at which the dancers began training and the peak hip adduction angle during landing (r = .358, P = .041). CONCLUSION: In executing a 30-cm drop landing, male and female dancers exhibited similar landing strategies and avoided landing patterns previously associated with increased injury rates. CLINICAL RELEVANCE: Commonly reported biomechanical differences between men and women, as well as the gender disparity among athletes in the incidence of ACL injuries, may be the result of inadequate experience in proper balance and landing technique rather than intrinsic gender factors. Beginning jump-specific and balance-specific training at an early age may counteract the potentially harmful adaptations in landing biomechanics observed in female athletes after maturity.

Barrios JA, Higginson JS, Royer TD, Davis IS. "Static and dynamic correlates of the knee adduction moment in healthy knees ranging from normal to varus-aligned."

2009 - Clin Biomech (Bristol, Avon). 2009 Dec;24(10):850-4. Epub 2009 Aug 22.

BACKGROUND: Individuals with medial knee osteoarthritis often present with varus knee alignment and ambulate with increased knee adduction moments. Understanding the factors that relate to the knee adduction moment in healthy individuals may provide insight into the development of this disease. Thus, this study aimed to examine the relationships of both static and dynamic lower extremity measures with the knee adduction moment. We hypothesized that the dynamic measures would be more closely related to this moment. METHODS: Arch height index, hip abduction strength and two static measures of knee alignment were recorded for 37 young asymptomatic knees that varied from normal to varus-aligned. Overground gait analyses were also performed. Correlation coefficients were used to assess the relationships between the static and dynamic variables to the knee adduction moment. Hierarchical regression analyses were then conducted using the static measures, the dynamic measures, and the static and dynamic measures together. RESULTS: Among the static measures, the tibial mechanical axis and the distance between the medial knee joint lines were correlated with the knee adduction moment. The best predictive static model (R(2)=0.53) included only the tibial mechanical axis. Among the dynamic variables, knee adduction and rearfoot eversion angles were correlated with the knee adduction moment. Knee adduction and rearfoot eversion, together, were the best dynamic model (R(2)=0.53). The static and dynamic measures together created the strongest of the three models (R(2)=0.59). CONCLUSIONS: These results suggest that dynamic measures slightly enhance the predictive strength of static measures when explaining variation in the knee adduction moment.

Reference

Bruening DA, Crewe AN, Buczek FL "A simple, anatomically based correction to the conventional ankle joint center"

2008 - Clinical Biomechanics 23(10):1299-1302

Background. Conventional motion analysis studies define the ankle joint center as the midpoint between the most medial and lateral aspects of the malleoli, yet research points toward a more distal joint center location. The purpose of this study was to develop and evaluate an anatomically based correction that would move the conventional ankle joint center to a more accurate location. Methods. Lower extremity radiographs from 30 pediatric patients were analyzed retrospectively. An offset between the conventional and more accurate ankle joint centers was measured and correlated to other common anatomical measures based on conventional skin mounted marker positions. The best correlated measure was used to define a simple correction factor, which was subsequently evaluated by its effect on six degree-of-freedom ankle joint translations during normal gait (n = 8). Findings. Shank length was found to have the highest bivariate linear correlation (r = 0.89) with the offset. Adjusting the ankle joint center using a percentage of shank length (2.7%) was also as accurate as the regression equation in predicting offset (mean error 0.6 mm, or 6% offset). Adjusting the ankle joint center using this simple percentage resulted in a 25% reduction in mean ankle joint translations during normal gait. Interpretation. The accuracy of the ankle joint center can be increased through a simple, anatomically based correction. This correction may prove beneficial in some kinematic and kinetic applications requiring increased anatomical fidelity.

Reference

Keefer M, King J, Powell D, Krusenklaus JH, Zhang S "Effects of modified short-leg walkers on ground reaction force characteristics."

2008 - Keefer, M, King, J, Powell, D, Krusenklaus, JH, Zhang, S. Effects of modified short-leg walkers on ground reaction force characteristics. Clin Biomech (Bristol, Avon). 2008; 23(9):1172-7.

BACKGROUND: Although short-leg walkers are often used in the treatment of lower extremity injuries (ankle and foot fractures and severe ankle sprains), little is known about the effect the short-leg walker on gait characteristics. The purpose was to examine how heel height modifications in different short-leg walkers and shoe side may affect ground reaction forces in walking. METHODS: Force platforms were used to collect ground reaction force data on 10 healthy participants. Five trials were performed in each of six conditions: lab shoes, gait walker, gait walker with heel insert on shoe side, gait walker modified with insert on walker side, equalizer walker, and equalizer walker with heel insert on shoe side. Conditions were randomized and walking speed was standardized between conditions. A 2x6 (sidexcondition) repeated analysis of variance was used on selected ground reaction force variables (P<0.05). FINDINGS: The application of a walker created peak vertical and anteroposterior ground reaction forces prior to the normal peaks associated with the loading response. Wearing a walker introduced an elevated minimum vertical ground reaction force in all conditions except the equalizer walker when compared to shoe on the shoe side. Peak propulsive anteroposterior ground reaction forces were smaller in all walker conditions compared to shoe on walker side. INTERPRETATION: The application of heel insert in gait walker with heel insert (on shoe side) and gait walker modified (on walker side) does not diminish the minimum vertical ground reaction force as hypothesized. Wearing a walker decreases the peak propulsive anteroposterior ground reaction force on the walker side and induces asymmetrical loading.

Reference

Zhang, S, Clowers, KG, Powell, D. "Ground reaction force and 3D biomechanical characteristics of walking in short-leg walkers"

2006 - Zhang, S, Clowers, KG, Powell, D. Ground reaction force and 3D biomechanical characteristics of walking in short-leg walkers. Gait Posture. 2006; 24(4):487-92.

Short-leg walking boots offer several advantages over traditional casts. However, their effects on ground reaction forces (GRF) and three-dimensional (3D) biomechanics are not fully understood. The purpose of the study was to examine 3D lower extremity kinematics and joint dynamics during walking in two different short-leg walking boots. Eleven (five females and six males) healthy subjects performed five level walking trials in each of three conditions: two testing boot conditions, Gait Walker (DeRoyal Industries, Inc.) and Equalizer (Royce Medical Co.), and one pair of laboratory shoes (Noveto, Adidas). A force platform and a 6-camera Vicon motion analysis system were used to collect GRFs and 3D kinematic data during the testing session. A one-way repeated measures analysis of variance (ANOVA) was used to evaluate selected kinematic, GRF, and joint kinetic variables (p<0.05). The results revealed that both short-leg walking boots were effective in minimizing ankle eversion and hip adduction. Neither walker increased the bimodal vertical GRF peaks typically observed in normal walking. However, they did impose a small initial peak (<1BW) earlier in the stance phase. The Gait Walker also exhibited a slightly increased vertical GRF during midstance. These characteristics may be related to the sole materials/design, the restriction of ankle movements, and/or the elevated heel heights of the tested walkers. Both walkers appeared to increase the demand on the knee extensors while they decreased the demand of the knee and hip abductors based on the joint kinetic results.

Reference

Cereatti A, Della Croce U, Cappozzo A "Reconstruction of skeletal movement using skin markers: Comparative assessment of bone pose estimators. "

2006 - Journal of NeuroEngineering and Rehabilitation, 3:7

Reference

Siegel KL, Kepple TM, O'Connell PO, Gerber LH, Stanhope SJ "Evaluation of foot function during the stance phase of gait."

1995 - Foot & Ankle International 16(12):764-770

Siegel KL, Stanhope SJ, Caldwell GE "Kinematic and kinetic adaptations in the lower limb during stance in gait of unilateral femoral neuropathy patients."

1993 - Clinical Biomechanics, 8:147-155

Barr AE, Siegel KL, Danoff JV, McGarvey CL III, Tomasko A, Sable I, Stanhope SJ "Biomechanical comparison of the energy storing capabilities of SACH and Carbon Copy II prosthetic feet during the stance phase of gait in a person with below knee amputation."

1992 - Physical Therapy 72(5):344-54

In this study, the energy-storing capabilities of solid-ankle cushion heel (SACH) and Carbon Copy II prosthetic feet during the stance phase of gait were compared. A person with a unilateral below-knee amputation served as a component of the instrumentation to test the feet under dynamic loads. Ten trials per foot of bilateral stride at "free" velocity were collected with a video-based, three-dimensional data-acquisition system and two force plates. There were no differences between the prosthetic conditions in step length, single-limb support time, and swing period (analysis of variance) or in double-limb support time, cadence, and velocity (Student's t test). Angular kinematics and moments of the hip and knee were unaffected bilaterally by the type of foot. The progression of the center of pressure under the Carbon Copy II was delayed from 15% to 80% of stance as compared with the SACH foot. The Carbon Copy II showed slower unloading in late stance and a later peak propulsive force than did the SACH foot. The Carbon Copy II performed greater work in both the energy-storage (Carbon Copy II = 2.33 J, SACH = 1.16 J) and energy-return (Carbon Copy II = 1.33 J, SACH = 0.34 J) phases of stance and returned energy with 57% efficiency. Although the energy returned by the Carbon Copy II was clinically insignificant during level walking, these results confirm that it performs as an energy-storing device.

Kepple TM, Stanhope SJ, Lohmann (Siegel) KN, Roman NL "A video-based technique for measuring ankle-subtalar motion during stance."

1990 - Journal of Biomedical Engineering 12(4):273-80

Kepple T., Stanhope S. A "A Video based, six degree of freedom approach for analyzing human motion."

1989 - Proceedings of the Fifth Annual East Coast Gait Laboratories Conference

Marker sets and placement papers:

Collins TD, Ghoussayni SN, Ewins DJ, Kent JA. "A six degrees-of-freedom marker set for gait analysis: repeatability and comparison with a modified Helen Hayes set."

2009 - Gait Posture. 2009 Aug;30(2):173-80. Epub 2009 May 26.Click here to read

Kinematic gait analysis is limited by simplified marker sets and related models. The majority of sets in clinical use were developed with low resolution imaging systems so required various assumptions about body behaviour. Further major limitations include soft tissue artefact and ambiguity in landmark identification. An alternative is the use of sets based on six degrees-of-freedom (DOF) principles, primarily using marker clusters for tracking. This study evaluates performance of a 6DOF set, based largely on CAST/ISB recommendations, through comparison with a conventional set and assessment of repeatability. Ten healthy subjects were assessed in treadmill walking, with both sets applied simultaneously on two occasions. Data were analysed using repeatability coefficients, correlation of key features, and comparison of joint angle curves and difference curves with confidence bands. Apart from pelvic tilt all segment and joint angles from both sets showed high within and between session repeatability (CMC>0.80). Hip rotations showed clear differences between the two sets with indications in support of the 6DOF set. Knee coronal angles showed evidence of cross-talk in the conventional set, highlighting difficulties with anatomical identification despite control measures such as a foot alignment template. Knee transverse angles showed inconsistent patterns for both sets. At the ankle the conventional set only allowed true measurement in two planes so with high repeatability the 6DOF set is preferable. The 6DOF set showed comparable performance to the conventional set and overcomes a number of theoretical limitations, however further development is needed prior to clinical implementation.

Manal, K., McClay, I., Stanhope, S., Richards, J., Galinat, B. "Comparison of surface mounted markers and attachment methods in estimating tibial rotations during walking: an in vivo study"

2000 - Gait and Posture 11:38-45

Karlsson D, Tranberg R "On skin movement artifact-resonant frequencies of skin markers attached to the leg."

1999 - Human Movement Science 18:627-635

McClay I, Manal K "Three-dimensional kinetic analysis of running: significance of secondary planes of motion."

1999 - Medicine and Science in Sports and Exercise 31:1629-1637

PURPOSE: The study of angular kinetic data provides important information regarding muscle function and may lend insight into the etiology of overuse injuries common to runners. These injuries are often due to deviations in the secondary planes of motion. However, little is known about the angular kinetics in these planes leaving no reference for comparison. METHODS: Therefore, three-dimensional kinematic and ground reaction force data were collected on 20 recreational runners with normal rearfoot mechanics. RESULTS: Findings suggest that sagittal plane kinetic data were similar to the two-dimensional studies reported in the literature. Sagittal plane data were least variable (CV: 9.3-11.0%) and comprised the largest percentage of positive or negative work done (80.2-88.8%) at both the rearfoot and knee joints. Transverse plane kinetics were most variable (CV: 68.5-151.9%) and constituted the smallest percentage of work done at both joints (0.7-7.4%). CONCLUSIONS: Although relatively smaller than the sagittal plane component, a substantial amount of positive work was done in the frontal plane at both joints (16.1-18.9%), suggesting that this component should not be ignored.

Fuller J, Lui LJ, Murphy MC, Mann RW "A comparison of lower- extremity skeletal kinematics measured using skin- and pin mounted markers."

1997 - Human Movement Science 16:219-242

Reinschmidt C, van den Bogert AJ, Nigg BM, Lundberg A, Murphy N "Effect of skin movement on the analysis of skeletal knee joint motion during running."

1997 - Journal of Biomechanics 30(7):729-732

Holden JP, Orsini JA, Siegel KL, Kepple TM, Gerber LH, Stanhope SJ "Surface movement errors in kinematic and kinetic measurement in gait."

1997 - Gait and Posture.

Cappozzo A, Cappello A, Della Croce U, Pensalfini P. "Surface-Marker Cluster Design Criteria for 3-D Bone Movement Reconstruction."

1997 - IEEE Transactions on Biomedical Engineering, 44 (12), p 1165-1174

Ball KA, Pierrynowski MR. "Classification of errors in locating a rigid body."

1996 - Journal of Biomechanics 29(9):1213-1217

This paper discusses the manner in which random Gaussian errors affect the determination of body segment kinematics. For the process of modelling rigid body (RB) motion, three types of kinematic errors, input, measured and theoretical, are identified. These correspond to errors in: the determination of three-dimensional observed points, the RB fit of those points, and the estimation of true RB positions, respectively. Of these, the theoretical error is most critical and most pivotal. Accuracy is provided when the theoretical error is minimised, yet only the measured error can be minimised by RB modelling algorithms. In computer simulations one may determine the effect that such manipulations have on theoretical error, yet in most experimental conditions this value may not even be calculated. Fortunately, computer simulations can be performed to determine the inter-relationships between the types of RB modelling errors. Such simulations can also be used to investigate the effects of RB shape. In this paper, Monte Carlo simulations were performed on three unit radius RBs; a triangle, a square and a tetrahedron. Although use of the triangle provided the lowest measured error, this also coincided with the greatest theoretical error. The use of redundant points was found to yield superior theoretical accuracies. A slight advantage was gained with use of the non-planar point arrangement on the tetrahedron, both the measured and theoretical errors were reduced. Finally, the superiority of RB modelling over individual point tracking was reflected in all of the results; between 33 and 50% of the input error was eliminated with the use of RB modelling.

Angeloni C, Cappozzo A, Catani F, Leardini A "Quantification of relative displacement of skin- and plate-mounted markers with respect to bones."

1993 - Journal of Biomechanics 26:864

Gait or lower body related papers:

Neckel ND, Blonien N, Nichols D, Hidler J "Abnormal joint torque patterns exhibited by chronic stroke subjects while walking with a prescribed physiological gait pattern"

2008 - J Neuroeng Rehabil. 2008; 5: 19.

BACKGROUND: It is well documented that individuals with chronic stroke often exhibit considerable gait impairments that significantly impact their quality of life. While stroke subjects often walk asymmetrically, we sought to investigate whether prescribing near normal physiological gait patterns with the use of the Lokomat robotic gait-orthosis could help ameliorate asymmetries in gait, specifically, promote similar ankle, knee, and hip joint torques in both lower extremities. We hypothesized that hemiparetic stroke subjects would demonstrate significant differences in total joint torques in both the frontal and sagittal planes compared to non-disabled subjects despite walking under normal gait kinematic trajectories. METHODS: A motion analysis system was used to track the kinematic patterns of the pelvis and legs of 10 chronic hemiparetic stroke subjects and 5 age matched controls as they walked in the Lokomat. The subject\\\\\\\'s legs were attached to the Lokomat using instrumented shank and thigh cuffs while instrumented footlifters were applied to the impaired foot of stroke subjects to aid with foot clearance during swing. With minimal body-weight support, subjects walked at 2.5 km/hr on an instrumented treadmill capable of measuring ground reaction forces. Through a custom inverse dynamics model, the ankle, knee, and hip joint torques were calculated in both the frontal and sagittal planes. A single factor ANOVA was used to investigate differences in joint torques between control, unimpaired, and impaired legs at various points in the gait cycle. RESULTS: While the kinematic patterns of the stroke subjects were quite similar to those of the control subjects, the kinetic patterns were very different. During stance phase, the unimpaired limb of stroke subjects produced greater hip extension and knee flexion torques than the control group. At pre-swing, stroke subjects inappropriately extended their impaired knee, while during swing they tended to abduct their impaired leg, both being typical abnormal torque synergy patterns common to stroke gait. CONCLUSION: Despite the Lokomat guiding stroke subjects through physiologically symmetric kinematic gait patterns, abnormal asymmetric joint torque patterns are still generated. These differences from the control group are characteristic of the hip hike and circumduction strategy employed by stroke subjects.

Reference

Svehlika M, Slaby K, Soumar L, Smetanaa P, Kobesovac A, and Trca T "Evolution of walking ability after soft tissue surgery in cerebral palsy patients: what can we expect? "

2008 - Journal of Pediatric Orthopaedics B 2008, 17:107–113

Eleven patients with spastic cerebral palsy were evaluated preoperatively, and 3 and 9 months postoperatively after soft tissue surgery. Evaluation included clinical examination, the Functional Mobility Scale questionnaire, and instrumented gait and center of mass trajectory analysis. A decrease in time–distance parameters after 3 months was followed by progress in all parameters at 9 months postoperatively. Push-off range of ankle motion decreased after surgery and was not restored to preoperative level until 9 months later. The center of mass vertical displacement improved significantly. The Functional Mobility Scale showed gait improvement. Despite the normalization of range of motion after surgery, there is an obvious period of functional gait deterioration in the early postoperative period and the push-off range of motion at the ankle did not recover to preoperative level until 9 months later.

Biomechanics and robotic devices:

Neckel ND, Blonien N, Nichols D, Hidler J "Abnormal joint torque patterns exhibited by chronic stroke subjects while walking with a prescribed physiological gait pattern"

2008 - J Neuroeng Rehabil. 2008; 5: 19.

BACKGROUND: It is well documented that individuals with chronic stroke often exhibit considerable gait impairments that significantly impact their quality of life. While stroke subjects often walk asymmetrically, we sought to investigate whether prescribing near normal physiological gait patterns with the use of the Lokomat robotic gait-orthosis could help ameliorate asymmetries in gait, specifically, promote similar ankle, knee, and hip joint torques in both lower extremities. We hypothesized that hemiparetic stroke subjects would demonstrate significant differences in total joint torques in both the frontal and sagittal planes compared to non-disabled subjects despite walking under normal gait kinematic trajectories. METHODS: A motion analysis system was used to track the kinematic patterns of the pelvis and legs of 10 chronic hemiparetic stroke subjects and 5 age matched controls as they walked in the Lokomat. The subject\\\\\\\'s legs were attached to the Lokomat using instrumented shank and thigh cuffs while instrumented footlifters were applied to the impaired foot of stroke subjects to aid with foot clearance during swing. With minimal body-weight support, subjects walked at 2.5 km/hr on an instrumented treadmill capable of measuring ground reaction forces. Through a custom inverse dynamics model, the ankle, knee, and hip joint torques were calculated in both the frontal and sagittal planes. A single factor ANOVA was used to investigate differences in joint torques between control, unimpaired, and impaired legs at various points in the gait cycle. RESULTS: While the kinematic patterns of the stroke subjects were quite similar to those of the control subjects, the kinetic patterns were very different. During stance phase, the unimpaired limb of stroke subjects produced greater hip extension and knee flexion torques than the control group. At pre-swing, stroke subjects inappropriately extended their impaired knee, while during swing they tended to abduct their impaired leg, both being typical abnormal torque synergy patterns common to stroke gait. CONCLUSION: Despite the Lokomat guiding stroke subjects through physiologically symmetric kinematic gait patterns, abnormal asymmetric joint torque patterns are still generated. These differences from the control group are characteristic of the hip hike and circumduction strategy employed by stroke subjects.

Reference

Lab calibration or CalTester related papers:

Holden JP, Selbie WS, Stanhope SJ "A proposed test to support the clinical movement analysis laboratory"

2003 - Gait and Posture 17 205-213

This paper describes a testing methodology and resultant set of four variables that can be used to quickly and easily document the correct installation, configuration, and combined working status of force platform (FP) and three-dimensional (3D) motion capture components of a clinical movement analysis (CMA) laboratory. Using a rigid, rod-shaped testing device, CMA laboratory data are collected simultaneously from the FP and motion capture components (typically, video-based kinematic measurements) as the device is manually loaded while being pivoted broadly about a point on the FP. Using a computational method based on static equilibrium, it is possible to independently measure the rod's orientation and tip position during the moving trial, using FP derived data exclusively, and to compare these estimates to rod orientation and tip position estimates derived exclusively from the motion capture component. The motion laboratory accreditation test (MLAT) variables include: the difference (angle) between the orientation of the long axis of the testing device as independently determined from kinematic measures (motion capture component) and the FP derived data; and the difference (x, y, z) between the center of pressure position (FP derived) and the position of the testing device tip (motion capture derived) that loads the FP. A numerical dynamics model was explored to evaluate the appropriateness of the static equilibrium-based FP data model and to determine guidelines for testing device movement frequency and FP loading. The MLAT technique provides a simple means of detecting the combined presence of errors from many sources, several of which are explored in this paper. The MLAT has been developed to help meet one criteria of the CMA laboratory accreditation process, and to serve as a routine quality assessment tool.

Reference