Protection by Ankle Brace for Lower-Extremity Joints in Half-Squat Parachuting Landing With a Backpack

Abstract

Half-squat parachuting landing is a kind of activity with high impact force. Injuries on lower-extremity joints are common in half-squat parachuting landing and would be increased with a backpack. An ankle brace was used to prevent ankle injuries in landing. However, few quantitative studies reported about the protection of an ankle brace for lower-extremity joints in half-squat parachuting landing with a backpack. This study focused on evaluating the protective effects of an ankle brace in half-squat parachuting landing with a backpack. Seven male participants landed from 120 cm with a backpack and an ankle brace. Each participant performed three landing trials on every experimental condition. Kinetics and kinematics of the hip, knee, and ankle were analyzed. It was found that the ankle brace did not significantly affect the ground reaction force with backpack but increased the ground reaction force from 14.7 ± 2.0 bodyweight to 16.2 ± 1.9 bodyweight (p = 0.017) without the backpack. The ankle brace significantly (p < 0.05) decreased the angular displacement, angular velocity, and angular acceleration of the ankle both without and with the backpack. In conclusion, the ankle brace could restrict ankle motion and significantly increase ground reaction force without the backpack. However, the ankle brace did not significantly influence ground reaction force and still restricted ankle motion with the backpack. Therefore, the ankle brace was more effective in half-squat parachuting landing with the backpack than no-backpack landing.

A prophylactic lumbosacral brace and the biomechanics of parachute landing

“…Niu et al suggested a linear relationship between peak vGRF and dropping height ( 33 ). Our previous study also demonstrated that wearing an ankle or knee brace reduced the peak vGRF, with the former showing enhanced effect ( 5 , 6 , 9 , 17 ). Our study suggested that wearing a brace reduced the peak vGRF by a maximum of 18.6%.…”

“…Since injuries associated with lower extremity joints (i.e., hip, knee, and ankle) and spine are more common during parachute landing, studies evaluating injury and its prevention are important for paratroopers ( 9 , 10 ). The ability to control the lower extremities upon landing is largely dependent on the motion of the lumbar spine ( 11 ).…”

Effect of Different Protection on Lateral Ankle during Landing: An Instantaneous Impact Analysis

“…These volunteers (average: 71.3 ± 5.4 Kg and 25 ± 1.8 years old) had no acute lower extremity injury or previous ankle injury or surgery. Subjects with ankle braces, boots, and no braces were made to stand on the predefined platform and jumped down from different height platforms (152 cm, 82 cm, and 52 cm) on a force plate [6,10] (FP4060-08-100, Bertec, Inc., Columbus, Ohio, USA) (Figure 1). One foot landed on the board, and the other foot was on the force plate.…”

“…Half-squat parachute landing in the Chinese Air Force is a kind of activity with high impact force [6]. The abnormal impact can change the kinematics and plantar loading of the lower extremities and increase injury risk [7].…”