Effects of ankle stabilizers on electromyographic activities of lower-extremity muscles during simulated half-squat parachute landing

Objective: To study effects of ankle stabilizer on electromyographic activities of lower-extremity muscles during the simulated half-squat parachute landing and its gender differences. Method: Eight male and eight female healthy adults were required to jump from a platform of 0.72 m high to simulate half-squat parachute landing. The experiment was divided into 3 groups: the barefoot one as control group, the group wearing tapes and braces respectively. The electromyogram (EMG) of each subject's tibial anterior, lateral gastrocnemius, biceps femoralis and rectus femoralis was measured. Two-way ANOVA was used to analyze and evaluate the effect of the stabilizers and genders on EMG variables. Results: The use of brace significantly increased the pre-landing EMG amplitude of the tibialis anterior for male (Control: 266 μV; Tape: 368 μV; Brace: 552 μV). The stabilizers had no significant effects on the other EMG parameters. Conclusions: Semi-rigid ankle braces are capable of arousing more active EMG of male's ankle flexor during half-squat parachute landing, but female does not share this predominance. Ankle stabilizers have no significant effects on EMG activities for knee joints.