Effects of Gluteus Medius and Around Ankle Muscle Strengthening on Static Balance and Muscle Activity in Individuals with Chronic Ankle Instability

Purpose: This study evaluated the effects of gluteus medius (GM) and ankle muscle strengthening exercises on muscle activity and static balance in individuals with chronic ankle instability (CAI).Methods: Forty-five CAI patients were randomly assigned to the GM exercise group (GE group; n = 15), ankle exercise group (AE group; n = 15), or control group (C group; n = 15).The GE group performed GM strengthening exercises, while the AE group focused on tibialis anterior (TA), peroneus longus (PL), and lateral gastrocnemius (LGCM) exercises.Both exercise programs were 40 minutes long; the C-group did not perform the exercises.Static balance and muscle activity were assessed using the one-leg standing test (OLST).The surface area ellipse (SAE) and muscle activity of the GM, TA, PL, and LGCM were measured preand postintervention.Data were analyzed using paired t-tests and one-way ANOVA with Bonferroni post hoc tests. Results:The results showed significant post-intervention SAE reductions for both the GE and AE groups (p < 0.05).The GE group showed a significant decrease in GM muscle activity, and the AE group showed a significant decrease in TA and PL activity (p < 0.05).The quantified change in the SAE from the OLST for the three groups pre-and postintervention was as follows: the SAE of the GE group demonstrated a greater reduction in SAE and GM activity than both the AE and C groups (p < 0.05). Conclusion:In this study, adult males' trunk muscle activity was lowest and subjective discomfort smallest with neutral grip while ramp climbing.Accordingly, we suggest that a neutral grip will help improve the function of the muscle skeleton system and reduce subjective discomfort by allowing ramp climbing to take less strain on the trunk muscles and maximize efficiency with less force.