Effect of Dry Needling on Spinal Reflex Excitability and Postural Control in Individuals With Chronic Ankle Instability

Objective: The purpose of this study was to compare postural control and neurophysiologic components of balance after dry needling of the fibularis longus between individuals with chronic ankle instability (CAI) and a healthy control group. Methods: This quasi-experimental university-laboratory study included 50 adult volunteers-25 with CAI (16 female, 9 male; age: 26 +/- 9.42 years; height: 173.12 +/- 9.85 cm; weight: 79.27 +/- 18 kg) and 25 healthy controls (15 female, 10 male; age: 25.8 +/- 5.45 years; height: 169.47 +/- 9.43 cm; weight: 68.47 +/- 13 kg). Participants completed the Star Excursion Balance Test (SEBT), single-leg balance, and assessment of spinal reflex excitability before and after a single treatment of dry needling to the fibularis longus. The anterior, posterolateral, and posteromedial directions of the SEBT were randomized, and reach distances were normalized to a percentage of leg length. A composite SEBT score was calculated by averaging the normalized scores. Postural control was assessed in single limb stance on a force plate through time-to-boundary measurements in eyes-open and eyes-closed conditions. Fibularis longus and soleus spinal reflexes were obtained by providing electrical stimulation to the common fibular and tibial nerves with participants lying prone. A Group x Time analysis examined changes in performance, and effect sizes were calculated to assess significance. Results: Significant group x time interactions were identified for composite (P = .006) and posteromedial (P = .017) SEBT scores. Significant time effects for all directions of the SEBT, time to boundary with eyes open, and the mediolateral direction with eyes closed indicate improved postural control following treatment (P < .008). Within group effect sizes for significant time effects ranged from small to large, indicating potential clinical utility. Conclusion: Dry needling demonstrated immediate short-term improvement in measures of static and postural control in individuals with CAI as well as healthy controls.