Performance analysis of unpowered lower limb exoskeleton during sit down and stand up

ABSTRACT Conventional unpowered lower limb exoskeleton paid little attention to the metabolic cost of body during sit down (SD)/stand up (SU). The SD motion model and characteristics extremity are analyzed; then, a novel is proposed, contribution degree muscles stiffness joints used for determining location energy storage element. relevant in left leg obtained based on Opensim software. results show that gracilis, rectus femoris (RF), long head biceps decreased about 13%, 9%, 68%, respectively. total 14% SD. However, RF, long/short increased 22%, 33%, 208%, 46%, And sartorius reduces 39%, 25.6% SU, under conditions. this study can provide theoretical basis optimal design exoskeleton.