Gluteus Medius for Individuals with Chronic Ankle Instability: Assessing Muscle Activity

Emerging evidence has suggested that gluteus medius (GM) muscle activity may be critical for functional performance in individuals with chronic ankle instability (CAI). This study aimed to systematically review the literature to determine whether there are differences in GM muscle activity between individuals with and without CAI. A comprehensive search in PubMed, Embase, Cochrane Library, Web of Science, EBSCO, and PEDro databases was undertaken from the year of inception to 10 June 2024. Studies that investigated GM muscle activity during physical activities in healthy controls or copers and individuals with CAI were included. The quality assessment was conducted using the Newcastle-Ottawa Quality scale (NOS). After review, forty studies (1840 participants) were included; NOS scoring for the included studies ranged from 5/9 to 9/9 stars. GM activity was reported for seven activities: walking (14 studies), stance-transition (four studies), jump-landing (13 studies), perturbation (six studies), balance (four studies), cutting (three studies), and other functional exercises (seven studies). The outcome measures selected to examine each task varied across studies, and electromyography (EMG) results were inconsistent. Overall, although the quality of the available studies was generally high, there were substantial methodological differences, and the activity of GM muscles in CAI participants compared to controls was equivocal. A consensus on standardization of GM muscle activity assessment reporting should be established to guide future studies.