The Body's Compensatory Responses to Unpredictable Trip and Slip Perturbations Induced by a Programmable Split-Belt Treadmill.

This paper investigates the influence of two types of gait perturbation (i.e., trip and slip) induced by a programmable split-belt treadmill on the body's compensatory responses. Our fall-inducing technology equipped with a commercially available programmable split-belt treadmill provides unpredictable trip and slip perturbations during walking. Two force plates beneath the split-belt treadmill and a motion capture system quantify the body's kinetic and kinematic behaviors, and a wireless surface electromyography (EMG) system evaluates the lower limb muscle activity. Twenty healthy young adults participated. The perturbations (i.e., trip and slip) were applied randomly to the participant's left foot between the 31st and 40th steps. The kinetic and kinematic behaviors and lower limb muscle activity were assessed during the standing, walking, and recovery periods. Compared with trip perturbations, stepping responses to slip perturbations were quicker and trunk, shoulder, and whole body center of mass movements after slip perturbations were higher; the EMG results showed that tibialis anterior, gastrocnemius, rectus femoris, and biceps femoris activities were also higher. The two common types of gait perturbation (i.e., trip and slip) induced by a commercially available programmable split-belt treadmill influenced the body's compensatory responses.