Effect Of Reduced Plantar Cutaneous Sensation On Balance Control Among People With Chronic Ankle Instability

PURPOSE: This study aimed to determine whether reduced plantar cutaneous sensation could influence dynamic and static balance control among people with chronic ankle instability (CAI). METHODS: Thirty-one people with CAI were recruited (female=7, age=22.03±1.73 years, height=174.41±9.83 cm, body mass=71.79±14.95 kg). Dynamic and static balance controls were represented by the reaching distances in the anterior (ANT), posteromedial (PM), and posterolateral (PL) directions during Y-Balance test (YBT), and the root-mean-square (RMS) of the center of pressure (CoP) in the anteroposterior (AP) and mediolateral (ML) directions during bilateral standing with eyes open. The participants placed their bare feet on shaved ice for 10 minutes to reduce plantar cutaneous sensation. Plantar cutaneous sensation at the 5th metatarsal was measured with a set of twenty Semmes-Westin monofilaments (SWM) to confirm reduced sensation. A higher value of SWM indicates a decreased sensation and higher threshold. Plantar cutaneous sensation threshold, YBT, and standing tests were conducted before (pre-ice) and after (post-ice) the ice immersion. Paired-sample t-tests were used to analyze data. RESULTS: Plantar cutaneous sensation threshold (pre-ice: 3.11±0.34 gauge, post-ice: 4.15±0.29 gauge, p<0.001, d=3.29) significantly increased after ice immersion. Reach distances in the ANT (pre-ice: 0.68±0.09 cm, post-ice: 0.65±0.09 cm, p<0.001, d=0.34), PM (pre-ice: 1.10±0.12 cm, post-ice: 1.05±0.14 cm, p=0.020, d=0.38), and PL (pre-ice: 1.15±0.09 cm, post-ice: 1.11±0.11 cm, p=0.013, d=0.40) directions, and the RMS of CoP in the AP direction (pre-ice: 7.17±5.05 mm, post-ice: 4.99±2.42 mm, p=0.011, d=0.55) significantly decreased after ice immersion. CONCLUSIONS: Acute ice-immersion-induced plantar cutaneous sensation reduction decreased dynamic balance control, while increased static balance control among people with CAI.