The Effect Of Peripheral Somatosensory Stimulation On Ankle Function In Individuals With Chronic Ankle Instability

Peripheral somatosensory stimulation (PSS) is a clinical intervention capable of improving neural and muscle function by increasing neural excitability in injured patients. PSS has been effective in improving function in neurologically-impaired populations, however, its effect in patients with chronic ankle instability (CAI) is unknown. The purpose of this study was to conduct a preliminary investigation of a single-session intervention of PSS to the ankle on neural excitability and dynamic balance in patients with CAI. Ten participants with CAI were recruited. Participants reported for 3 total sessions: a control session, an intervention session, and a 24-hr follow-up. Neural excitability was measured each session through reflexive excitability from the Hoffman-reflex (H-reflex) as well as through measures of transcranial magnetic stimulation (TMS). Dynamic postural stability indices (DPSI) were also measured each session from an in-ground force plate while electromyography (EMG) data was extracted from the lower leg muscles during a hop-to-stabilization task. No significant differences were observed for neural excitability nor dynamic balance measures following treatment. Medium-large effect sizes for some neural excitability variables prompted us to further investigate the data. Encouraging effect sizes were seen across these measures from Pre-Intervention to Post-Intervention time points, however DPSI measures still revealed minimal changes.