Objective:To provide an effective protection method for reducing the ankle injury during airborne force landing by investigating the protective effect of a protective ankle brace (PAB).Methods:Airborne soldiers were selected as subjects and they were asked to jump from 1.5 m and 2 m high training platform with and without PAB protection. They maintained a standard bending and knee-bending posture as they touched the buffer surface of the training ground. Each subject completed 4 simulated landing trials: from 1.5 m with PAB (1.5 m PAB group), from 2 m with PAB (2 m PAB group), from 1.5 m without PAB (1.5 m control group), and from 2 m without PAB (2 m control group). The muscle electrical signals of bilateral tibialis anterior, peroneal longus and brevis and gastrocnemius were recorded by surface electromyography, and the percentage of maximal voluntary electrical activation (MVE%) was calculated and analyzed.Results:Sixty-one subjects were included. At the same height with different ankle protection status, the MVE% values of bilateral tibialis anterior and gastrocnemius in the 1.5 m PAB group were lower than those in the 1.5 m control group, and the differences were significant ( t=2.45, 2.74, 2.35, P=0.017, 0.008, 0.022). The MVE% values of bilateral peroneus longus and brevis in the 1.5 m PAB group were higher than those in the 1.5 m control group, and the differences were significant ( t=5.28, 4.56, both P<0.001). The MVE% values of left tibialis anterior and left gastrocnemius in the 2 m PAB group were lower than those in the 2 m control group, and the differences were significant ( t=2.21, 0.53, 4.35, P=0.031, 0.598, <0.001). The MVE% values of bilateral peroneus longus and brevis in the 2 m PAB group were higher than those in the 2 m control group, and the differences were significant ( t=4.92, 6.31, both P<0.001). With the ankle protection the MVE% values of bilateral tibialis anterior, gastrocnemius, peroneus longus and brevis in the 1.5 m PAB group were lower than those in the 2 m PAB group, and the differences were significant ( t=3.56-4.94, all P≤0.001). The MVE% values of bilateral tibialis anterior, gastrocnemius, peroneus longus and brevis in the 1.5 m control group were lower than those in the 2 m PAB group, and the differences were significant ( t=2.30-5.85, all P<0.05). Conclusions:PAB can reduce the ankle injury during airborne force landing and provide good protection.

Objective:To provide an effective protection method for reducing the ankle injury during airborne force landing by investigating the protective effect of a protective ankle brace (PAB).Methods:Airborne soldiers were selected as subjects and they were asked to jump from 1.5 m and 2 m high training platform with and without PAB protection. They maintained a standard bending and knee-bending posture as they touched the buffer surface of the training ground. Each subject completed 4 simulated landing trials: from 1.5 m with PAB (1.5 m PAB group), from 2 m with PAB (2 m PAB group), from 1.5 m without PAB (1.5 m control group), and from 2 m without PAB (2 m control group). The muscle electrical signals of bilateral tibialis anterior, peroneal longus and brevis and gastrocnemius were recorded by surface electromyography, and the percentage of maximal voluntary electrical activation (MVE%) was calculated and analyzed.Results:Sixty-one subjects were included. At the same height with different ankle protection status, the MVE% values of bilateral tibialis anterior and gastrocnemius in the 1.5 m PAB group were lower than those in the 1.5 m control group, and the differences were significant ( t=2.45, 2.74, 2.35, P=0.017, 0.008, 0.022). The MVE% values of bilateral peroneus longus and brevis in the 1.5 m PAB group were higher than those in the 1.5 m control group, and the differences were significant ( t=5.28, 4.56, both P<0.001). The MVE% values of left tibialis anterior and left gastrocnemius in the 2 m PAB group were lower than those in the 2 m control group, and the differences were significant ( t=2.21, 0.53, 4.35, P=0.031, 0.598, <0.001). The MVE% values of bilateral peroneus longus and brevis in the 2 m PAB group were higher than those in the 2 m control group, and the differences were significant ( t=4.92, 6.31, both P<0.001). With the ankle protection the MVE% values of bilateral tibialis anterior, gastrocnemius, peroneus longus and brevis in the 1.5 m PAB group were lower than those in the 2 m PAB group, and the differences were significant ( t=3.56-4.94, all P≤0.001). The MVE% values of bilateral tibialis anterior, gastrocnemius, peroneus longus and brevis in the 1.5 m control group were lower than those in the 2 m PAB group, and the differences were significant ( t=2.30-5.85, all P<0.05). Conclusions:PAB can reduce the ankle injury during airborne force landing and provide good protection.