Date of Award


Document Type


Degree Name

Master of Science (MS)


School of Kinesiology and Recreation

First Advisor

Adam E Jagodinsky


A deeper understanding of the response to an unexpected ankle perturbation could help provide insight into ankle sprain injury avoidance strategies. This study compared lower extremity electromyographic and kinematic measures between unexpected ankle perturbation and normal walking conditions, including muscle amplitudes and reaction times, dominant limb joint angles and velocities. Trial conditions included a walking control condition, unexpected 30° inversion, and unexpected 18° combined inversion and plantarflexion. With randomized trials, 20 healthy volunteers walked along the custom-built walkway that unexpectedly released into the described ankle perturbations. Significant differences were found for peak and average EMG of the peroneus longus and rectus femoris, time to peak EMG and reaction time of the ipsilateral and contralateral gluteus medius, peak joint angles, peak joint velocities, and time to peak joint angles. The differences found provide evidence that points towards a systemic response with involvement at each joint of the lower extremity and muscles within the kinetic chain.


Imported from Schempp_ilstu_0092N_11904.pdf


Page Count


Included in

Biomechanics Commons