Bilateral lower limb biomechanical abnormalities in patients with unilateral chronic ankle instability

Guo Ping; Wang Juan

doi:10.12307/2025.974

Abstract：BACKGROUND:Recent studies have shown that patients with unilateral chronic ankle instability have bilateral sensorimotor impairment.However,it is still unknown how bilateral sensorimotor impairment affects the biomechanical characteristics of the affected and unaffected sides. OBJECTIVE:To investigate the kinematic and kinetic characteristics of the bilateral lower limbs in patients with unilateral chronic ankle instability during lateral cuttng maneuver. METHODS:Eighteen patients with unilateral chronic ankle instability and eighteen healthy subjects were recruited.The patients with chronic ankle instability completed 90° cuttng on the affected and healthy sides.The healthy subjects completed 90° cuttng on the dominant side.The kinematic parameters of the lower limbs during lateral incision were collected using an infrared high-speed motion capture system,and the kinetic parameters of the lower limbs were collected using a three-dimensional force platform.Paired and independent sample t-tests were used to compare differences in various biomechanical variables. RESULTS AND CONCLUSION:(1)Compared with healthy subjects,patients with chronic ankle instability showed higher ankle inversion(P=0.047)and internal rotation(P=0.046)angles on the affected side,and higher ankle inversion angles(P=0.049)on the unaffected side.Compared with the affected side,the knee valgus(P<0.001)and hip adduction(P=0.046)angles of patients with chronic ankle instability were significantly increased on the unaffected side.(2)Compared with healthy subjects,patients with chronic ankle instability showed higher knee extension moment on the affected side(P=0.029).Compared with the affected side,the plantar flexion moment of the ankle on the unaffected side of patients with chronic ankle instability was significantly increased(P=0.027),and the extension moment of the knee was significantly reduced(P=0.048).To conclude,patients with unilateral chronic ankle instability have abnormal biomechanical characteristics of the lower limbs not only on the affected side but also on the unaffected side,and there are potential risks of"giving way"or recurrence ankle sprains on both sides.Furthermore,patients with unilateral chronic ankle instability also exhibit changes in the biomechanical characteristics of the proximal joints in the coronal plane on the affected side.