Asymmetry in Three-Dimensional Sprinting with and without Running-Specific Prostheses

As a whole, human sprinting seems to be completely periodic and symmetrical motion. This view is changed when person runs with running-specific prosthesis after unilateral amputation. The aim of our study investigate differences similarities between below-knee amputee non-amputee sprinters—especially regard whether asymmetry distracting factor for sprint performance. We established three-dimensional rigid multibody models one transtibial athlete reference purposes three athletes. They consist 16 bodies (head, ipper, middle lower trunk, upper arms, hands, thighs, shanks feet/running specific prosthesis) 30 or 31 degrees freedom (DOFs) the athletes, respectively. Six DOFs are associated floating base, remaining ones rotational DOFs. internal joints equipped torque actuators except prosthetic ankle joint. To model spring-like properties prosthesis, actuator replaced by linear spring-damper system. consider pair steps which modeled as multiphase problem each step consisting flight, touchdown single-leg contact phase. Each phase described its own set differential equations. By combining motion capture recordings least squares optimal control formulation including constraints, we reconstructed dynamics trial athlete. results show that even athletes showed less than expected examined on an individual level. Nevertheless, much more pronounced in applies larger torques arm trunk compensate experiences destabilizing influence movement. Hence, inter-limb has significant effect movement maintenance upright body position.