Dry Needling Improves Static and Dynamic Balance in Individuals with Chronic Ankle Instability

Abstract

Individuals with chronic ankle instability (CAI) commonly exhibit balance deficits that are associated with dysfunction of the fibularis longus (FL) muscle. Dry needling (DN) is a treatment that targets muscular trigger points and is hypothesized to improve neurophysiological function of treated muscles. The ability of FL DN to improve dynamic and static balance in patients with CAI is unknown. PURPOSE: Examine the effect of FL DN on dynamic and static balance in individuals with CAI. METHODS: Twenty-five adults with CAI (9 males, 16 females; 26±9.42 years; 173.12±9.85cm; 79.27±18kg) volunteered to participate. Participants completed the Star Excursion Balance Test (SEBT) and postural control measures before and immediately after a single DN treatment to the FL. The anterior, posterolateral, and posteromedial directions of the SEBT were tested in a random order and reach distances were normalized to a percent of leg length. A composite SEBT score was calculated by dividing the normalized, average scores in each direction by three. Postural control was assessed in single-limb stance on a forceplate through time to boundary (TTB) measurements and calculated in the mediolateral and anteroposterior directions under eyes open and eyes closed conditions. A single DN treatment was performed on the FL using a “pistoning” technique. Descriptive statistics (mean change ± SD), paired t-tests, and standardized response mean effect sizes were calculated to compare balance measures before and immediately after the FL DN intervention (p≤0.05). RESULTS: Following DN, significant improvements were identified in the composite (3.98± 4.45%, p<0.001, ES=0.89), posteromedial (4.85±5.75%, p <0.001, ES=0.84) and posterolateral reach directions (4.96±5.49%, p<0.001, ES=0.90) but not in the anterior reach direction (2.11±5.77%, p=0.08, ES=0.37). Under eyes-open conditions, TTB improved in the mediolateral (0.27±0.43, p=0.004, ES=0.63) and anteroposterior (0.84±1.43, p=0.007, ES=0.59) directions., However, no significant changes were identified in any TTB measures with eyes closed (p≤0.20). CONCLUSIONS: FL DN created immediate improvements in dynamic and static balance in individuals with CAI. Future studies should examine the effects of multiple DN treatments and the mechanism behind this therapeutic effect.