BADGER Lab member Jenna Thorp published a study on how human walking entrains to rhythmic electrical stimulation of the medial gastrocnemius muscle unilaterally. Based on past literature showing that the body entrains to align robotic ankle plantarflexion torque pulses to coincide with push-off, we studied whether the electrical stimulation could turn the plantarflexor muscles into the actuator and elicit the same effect. It did, but with two timings: near push-off and near heel-strike. Tendon tensiometry revealed that electrical stimulation elicited substantial increases in plantarflexor tension when underlying tension was low, but minimal effect when underlying tension was high. The study may inform future work on electrical stimulation for control or modification of gait.
J. E. Thorp and P. G. Adamczyk, “Mechanisms of gait phase entrainment in healthy subjects during rhythmic electrical stimulation of the medial gastrocnemius,” PLOS ONE, vol. 15, no. 10, p. e0241339, Oct. 2020, doi: 10.1371/journal.pone.0241339.