Effect of chronic ankle instability on lower extremity kinematics, dynamic postural stability, and muscle activity during unilateral jump-landing tasks: A systematic review and meta-analysis

To determine if individuals with chronic ankle instability (CAI) demonstrate altered landing kinematics, muscle activity, and impaired dynamic postural stability during a unilateral jump-landing task.21 studies were included from PubMed, MEDLINE, Embase and CINAHL searched on September 26, 2021. Mean differences in joint angles and muscle activity between CAI and controls were analysed as continuous variables and pooled using a random-effects model to obtain standardised mean differences and 95% confidence intervals. Dynamic postural stability measured using time to stabilisation (TTS) was assessed qualitatively.We found greater plantarflexion (pooled SMD = 0.33, 95%CI [0.02,0.65]), reduced knee flexion (pooled SMD = -0.67, 95%CI [-0.97, -0.37]), and reduced hip flexion (pooled SMD = -0.52, 95%CI [-0.96, -0.07]) in CAI after landing. Regarding muscle activity, we observed reduced peroneus longus muscle activation (pooled SMD = -0.77, 95% CI [-1.17, -0.36]) in CAI prior to landing.Our study provides preliminary evidence of altered landing kinematics in the sagittal plane and reduced peroneus muscle activity in CAI during a dynamic jump-landing task. These results may have clinical implications in the development of more effective and targeted rehabilitation programmes for patients with CAI.