External ankle support effects on ankle biomechanics in chronic ankle instability: systematic review and meta-analysis

Abstract

Objective To systematically review the literature to determine whether external ankle supports influence ankle biomechanics in chronic ankle instability (CAI) participants during sports-related tasks. Data Sources A literature search of MEDLINE, SPORTDiscus, and CINAHL databases was conducted in November 2021. Study Selection Included studies were randomised cross-over or parallel-group controlled trials with CAI participants using external ankle supports, compared to no support, assessing ankle biomechanics during landing, running, or change of direction. Data Extraction Two authors independently conducted study identification, data extraction, risk of bias (RoB2), and quality of evidence (GRADE) assessments. Meta-analysis using random-effects was used to compare between-group mean differences (MD) with 95% confidence intervals (CI). GRADE recommendations were used to determine the certainty of findings. Data Synthesis Thirteen studies of low to moderate risk of bias were included. During landing, very low-grade evidence indicate external ankle supports reduce frontal plane excursion (MD [95% CI] −1.83° [−2.97, −0.69], p=0.002), plantarflexion ground contact angle (−3.86° (−6.18, −1.54), p=0.001), sagittal plane excursion (−3.45° [−5.00, −1.90], p<0.001), but not inversion ground contact angle (−1.00° [−3.59, 1.59], p=0.45). During running, very low to low-grade evidence indicate external ankle supports reduce sagittal plane excursion (−5.21° [−8.59, −1.83], p=0.003), but not inversion ground contact angle (0.32° [−2.11, 1.47], p=0.73), frontal plane excursion (−1.31° [−3.24, 0.63], p=0.19), or plantarflexion ground contact angle (−0.12° [−3.54, 3.29], p=0.94). There were insufficient studies investigating changes of direction. Conclusion There is low to very low-grade evidence that external ankle supports reduce frontal plane excursion but not inversion ground contact angle in CAI participants during landing. Limiting frontal plane excursion may reduce ankle sprain risk. Frontal plane ankle kinematics were not influenced by external ankle supports during running. Sagittal plane reductions were observed with external ankle supports during landing and running, but its influence on ankle sprain risk is undetermined.