Development of Muscle Actuated Robotic System for the Investigation of Lower Extremity Function

Prior to automotive impact, occupants often engage their muscles to brace themselves for collision, and despite this fact, few injury prediction tools take into account the effect of active musculature during injury. This study details the development and initial testing of a Muscle Actuated Robotic System (MARS), which could eventually be used to examine the effect of musculature on injury. The proof of concept study for MARS is to investigate the effect of body weight on bony kinematics in the foot during walking. Development of the MARS included coupling both the hardware and control systems of a 6-degree of freedom position and force/torque controlled serial robot with a set of nine linear actuators. Results show the MARS is capable of replicating human-like gait, reproducing the target tibia kinematics within 1 mm and 0.1 degree respectively, and that both, the calcaneus rolls, and the midfoot arch drop increased with the increase of input body weight. Although the current study evaluates gait, the robotic system is capable of applying muscle forces throughout various joints in the body.