Effects of elastic ankle braces on dynamic stability in patients with functional ankle instability

To investigate the protective effects of ankle braces in patients with functional ankle instability. This retrospective study involved 30 participants recruited from January 2023 to December 2023 at School of Physical Education, Nanchang University. These participants were divided into an ankle brace group wearing braces and a control group without braces. The biomechanical parameters of lower extremity were collected by infrared motion capture and three-dimensional force plate. The parameters were compared between two groups. Regardless of movement patterns, no significant differences were found for vGRF peak, time to peak of vGRF, range of sagittal motion, knee flexion angle at the landing moment, knee varus-valgus angle at the landing moment, knee internal rotation angle at the landing moment, knee range of sagittal motion, knee range of frontal motion, knee range of horizontal motion, knee flexion moment peak, knee extension moment peak, knee varus moment peak, knee valgus moment peak and the knee internal rotation moment peak between ankle brace group and the control group. In addition, peak of ankle varus angle (walking pattern and running pattern: all P<0.001), speed of ankle varus angle (walking pattern: P=0.003; running pattern: P=0.023), the knee external rotation moment peak (walking pattern: P=0.026; running pattern: P=0.031) and energy absorption of knee joints (walking pattern: P=0.034, running pattern: P=0.029) in ankle group were significantly lower than those in control group, while peak of ankle valgus torque (walking pattern: P=0.002, running pattern: P<0.001) in ankle group was obviously more than that in control group. The protective effects of elastic ankle brace for functional ankle instability were more prominent in contrast to that without ankle brace support. Elastic ankle braces could be used as an effective measure to prevent the ankle sprain in patients with functional ankle instability.