Modeling the Effects of Linear and Torsional Spring Based Passive Assistance on Human Gait

Abstract

Older adults and people with various neurological diseases need some external assistance even during normal walking. Amongst various factors, due to a decrease in the muscle strength, they are not able to produce a large force that significantly affects the pre-swing phase of their gait cycle, an important determinant of walking speed. While there is significant work done on active assistance for walking, almost no work has been reported on the effect of torsional spring and combinations of torsional and linear springs as a mode of passive assistance. OpenSim was used to model the effects of linear and torsional spring-based passive assistance on the total metabolic energy and ankle moment during human gait. A total of six conditions were simulated out of which five gave satisfactory findings. Particularly, a combination of ankle torsional and gastrocnemius path springs showed the largest reduction in the peak total metabolic energy and peak plantar flexor moment during the pre-swing phase of the gait cycle, suggesting that such passive assistance could be used as an effective mode of support for walking.