Engineering Commons^™

A Biomechanical Model For The Validation Of Modular Control In Balance, S. Piazza, M. Mansouri, D. Torricelli, Jeffrey A. Reinbolt, J. L. Pons

Jeffrey A. Reinbolt

No abstract provided.

The Use Of A Platform For Dynamic Simulation Of Movement: Application To Balance Recovery, M. B. Mansouri, A. E. Clark, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Muscle Force Estimates During The Weight-Acceptance Phase Of Single-Leg Jump Landing, K. D. Morgan, C. J. Donnelly, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Using Principal Components Analysis To Model Muscle Force Contribution In Acl Injury, K. D. Morgan, M. H. Morgan, C. B. Donnelly, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Optimizing Whole-Body Kinematics To Minimize Valgus Knee Loading During Sidestepping: Implications For Acl Injury Risk, C. J. Donnelly, D. G. Lloyd, B. C. Elliott, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

The kinematic mechanisms associated with elevated externally applied valgus knee moments during non-contact sidestepping and subsequent anterior cruciate ligament (ACL) injury risk are not well understood. To address this issue, the residual reduction algorithm (RRA) in OpenSim was used to create nine subject-specific, full-body (37 degrees of freedom) torque-driven simulations of athletic males performing unplanned sidestep (UnSS) sport tasks. The RRA was used again to produce an optimized kinematic solution with reduced peak valgus knee torques during the weight acceptance phase of stance. Pre-to-post kinematic optimization, mean peak valgus knee moments were signifi- cantly reduced by 44.2 Nm (p ¼ …

A Platform For Dynamic Simulation And Control Of Movement Based On Opensim And Matlab, M. B. Mansouri, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

Numerical simulations play an important role in solving complex engineering problems and have the potential to revolutionize medical decision making and treatment strategies. In this paper, we combine the rapid model-based design, control systems and powerful numerical method strengths of MATLAB/ Simulink with the simulation and human movement dynamics strengths of OpenSim by developing a new interface between the two software tools. OpenSim is integrated with Simulink using the MATLAB S-function mechanism, and the interface is demonstrated using both open-loop and closed-loop control systems. While the open-loop system uses MATLAB/Simulink to separately reproduce the OpenSim Forward Dynamics Tool, the closed-loop …

Crouched Posture Maximizes Ground Reaction Forces Generated By Muscles, H. X. Hoang, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

Crouch gait decreases walking efficiency due to the increased knee and hip flexion during the stance phase of gait. Crouch gait is generally considered to be disadvantageous for children with cerebral palsy; however, a crouched posture may allow biomechanical advantages that lead some children to adopt a crouch gait. To investigate one possible advantage of crouch gait, a musculoskeletal model created in OpenSim was placed in 15 different postures from upright to severe crouch during initial, middle, and final stance of the gait cycle for a total of 45 different postures. A series of optimizations was performed for each posture …

Development Of An Opensim Shoulder Model For Manual Wheelchair Users With Tetraplegia, B. Odle, G. Forrest, T. Dyson-Hudson, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

A Platform For Dynamic Simulation And Control Of Human Movement, M. B. Mansouri, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Tendon Transfer Of Biarticular Muscles Reduces Balance Recovery: A Computer Simulation Study, A. E. Clark, A. Seth, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Weakened Trunk Muscles Influence Knee Valgus Moments Associated With Acl Injury, K. D. Morgan, C. J. Donnelly, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Muscle Forces During Single-Leg Jump Landing, K. D. Morgan, C. J. Donnelly, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Crouched Posture Maximizes Ground Reaction Forces Generated By Muscles, H. X. Hoang, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Optimizing Whole-Body Kinematics To Minimize Valgus Knee Loading During Single-Leg Landing: Implications For Acl Injury Risk, C. J. Donnelly, D. G. Lloyd, B. C. Elliott, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Biarticular Muscles Influence Postural Responses: Implications For Treatment Of Stiff-Knee Gait, A. E. Clark, A. Seth, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Simulation Of Human Movement Based On Opensim, Jeffrey A. Reinbolt, A. Seth, S. L. Delp

Jeffrey A. Reinbolt

No abstract provided.

A Musculoskeletal Modeling And Simulation Framework For In Silico Investigations And Exchange, A. Seth, M. Sherman, Jeffrey A. Reinbolt, S. L. Delp

Jeffrey A. Reinbolt

No abstract provided.

Simulation Of Human Movement: Applications Using Opensim, Jeffrey A. Reinbolt, A. Seth, S. L. Delp

Jeffrey A. Reinbolt

Computer simulations are playing an increasingly important role in solving complex engineering problems, and have the potential to revolutionize experimentally-based medical decision making and treatment design. Experiments alone provide important but limited understanding of movement dynamics. Although we can measure some quantities, such as muscle activities and ground reaction forces, responsible for a movement, simulations complement these measurements with estimates of other important variables, such as muscle and joint forces. Simulations also allow us to establish cause-and-effect relationships giving insights into muscle function. Perhaps the most exciting feature of simulations is the potential to perform “what if” studies to test …

Opensim: A Musculoskeletal Modeling And Simulation Framework For In Silico Investigations And Exchange, A. Seth, M. A. Sherman, Jeffrey A. Reinbolt, S. L. Delp

Jeffrey A. Reinbolt

Movement science is driven by observation, but observation alone cannot elucidate principles of human and animal movement. Biomechanical modeling and computer simulation complement observations and inform experimental design. Biological models are complex and specialized software is required for building, validating, and studying them. Furthermore, common access is needed so that investigators can contribute models to a broader community and leverage past work. We are developing OpenSim, a freely available musculoskeletal modeling and simulation application and libraries specialized for these purposes, by providing: musculoskeletal modeling elements, such as biomechanical joints, muscle actuators, ligament forces, compliant contact, and controllers; and tools for …

Dynamic Simulation Of Movement Based On Opensim And Matlab/Simulink, M. B. Mansouri, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Minimizing Valgus Knee Loading During Sidestepping: Implications For Acl Injury Risk, C. J. Donnelly, D. G. Lloyd, B. C. Elliott, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Posture Influences Ground Reaction Force: Implications For Crouch Gait, H. X. Hoang, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Improving Computed Muscle Control Through Optimization To Generate Dynamic Simulations Of Overground Running, Jeffrey A. Reinbolt, C. J. Donnelly

Jeffrey A. Reinbolt

No abstract provided.

Musculoskeletal Modeling: How It Began, What It Offers, And Where It Is Heading, A. Seth, Jeffrey A. Reinbolt, S. L. Delp

Jeffrey A. Reinbolt

No abstract provided.

Mechanical Advantage Of Crouch Gait, Jeffrey A. Reinbolt, A. Seth, J. L. Hicks, S. L. Delp

Jeffrey A. Reinbolt

No abstract provided.

Mechanisms Of Improved Knee Flexion After Rectus Femoris Transfer Surgery, M. D. Fox, Jeffrey A. Reinbolt, J. A. Ounpuu, S. L. Delp

Jeffrey A. Reinbolt

No abstract provided.

Emerging Challenges In Multiscale Modeling In Biology, R. Kerckhoffs, J. Bassingthwaighte, Jeffrey A. Reinbolt, P. Arzberger

Jeffrey A. Reinbolt

No abstract provided.

Predicting Outcomes Of Rectus Femoris Transfer Surgery, Jeffrey A. Reinbolt, M. D. Fox, M. H. Schwartz, S. L. Delp

Jeffrey A. Reinbolt

Rectus femoris transfer surgery is a common treatment for stiff knee gait in children with cerebral palsy. Unfortunately, the improvement in knee motion after surgery is inconsistent. There is great interest in understanding the causes of stiff knee gait and determining predictors of improved knee motion after surgery. This study demonstrates that it is possible to predict whether or not a patient’s kneemotion will improve following rectus femoris transfer surgery with greater than 80% accuracy. A predictive model was developed that requires only a few preoperative gait analysis measurements, already collected as a routine part of treatment planning. Our examination …

Multiscale Modeling In Computational Biomechanics: Determining Computational Priorities And Addressing Current Challenges, M. Tawhai, J. Bischoff, D. Einstein, A. Erdemir, T. Guess, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

doi: 10.1109/MEMB.2009.932489

Limitations Of Parallel Global Optimization For Large-Scale Human Movement Problems, B. I. Koh, Jeffrey A. Reinbolt, A. D. George, R. T. Haftka, B. J. Fregly

Jeffrey A. Reinbolt

Global optimization algorithms (e.g., simulated annealing, genetic, and particle swarm) have been gaining popularity in biomechanics research, in part due to advances in parallel computing. To date, such algorithms have only been applied to small- or medium-scale optimization problems (<100 design vari- ables). This study evaluates the applicability of a parallel particle swarm global optimization algorithm to large-scale human movement problems. The evaluation was performed using two large-scale (660 design variables) optimization problems that utilized a dynamic, 27 degree-of-freedom, full-body gait model to predict new gait motions from a nominal gait motion. Both cost functions minimized a quantity that reduced the external knee adduction torque. The first one minimized footpath errors corresponding to an increased toe out angle of 15◦ , while the second one minimized the knee adduction torque directly without changing the footpath. Constraints on allowable changes in trunk orientation, joint angles, joint torques, centers of pressure, and ground reactions were handled using a penalty method. For both prob- lems, a single run with a gradient-based nonlinear least squares algorithm found a significantly better solution than did 10 runs with the global particle swarm algorithm. Due to the penalty terms, the physi- cally realistic gradient-based solutions were located within a narrow “channel” in design space that was difficult to enter without gradient information. Researchers should exercise caution when extrapolating the performance of parallel global optimizers to human movement problems with hundreds of design variables, especially when penalty terms are included in the cost function.

doi:10.1016/j.medengphy.2008.09.010