Lower-Extremity Electromyography Measures During Walking With Ankle-Destabilization Devices

Context: Ankle-destabilization devices are rehabilitation tools that may improve neuromuscular control by increasing lower-extremity muscle activation. Their effects should be tested in healthy individuals before being implemented in rehabilitation programs. Objective: To compare EMG activation of lower-extremity muscles during walking while wearing 2 different ankle-destabilization devices. Design: Crossover. Setting: Laboratory. Participants: 15 healthy young adults (5 men, 10 women). Intervention: Surface EMG activity was recorded from the anterior tibialis, peroneus longus, lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius as subjects walked on a treadmill shod, with an ankle-destabilization boot (ADB), and an ankle-destabilization sandal (ADS). Main Outcome Measures: Normalized amplitudes 100 ms before and 200 ms after initial heel contact, time of onset activation relative to initial contact, and percent of activation time across the stride cycle were calculated for each muscle in each condition. Results: The precontact amplitudes of the peroneus longus and lateral gastrocnemius and the postcontact amplitudes of the lateral gastrocnemius were significantly greater in the ADB and ADS conditions. In the ADB condition, the rectus femoris and biceps femoris postcontact amplitudes were significantly greater than shod. The peroneus longus and lateral gastrocnemius were activated significantly earlier, and the anterior tibialis, lateral gastrocnemius, and rectus femoris were activated significantly longer across the stride cycle in the ADB and the ADS conditions. In addition, the peroneus longus was activated significantly longer in the ADB condition when compared with shod. Conclusions: Both ankle-destabilization devices caused an alteration in muscle activity during walking, which may be favorable to an injured patient. Therefore, implementing these devices in rehabilitation programs may be beneficial to improving neuromuscular control.