Effect Of Acute-reduction Plantar Cutaneous Sensation On Dynamic Stability In People With Chronic Ankle Instability

PURPOSE: This study aimed to investigate whether reduced plantar cutaneous sensation could influence dynamic stability at ankle in people with chronic ankle instability (CAI) during single-leg drop landing. METHODS: Fourteen adults with CAI were recruited in this study (female: 6, age: 22.03±1.73 years, height: 1.72±0.11 m, body mass: 71.53±15.49 kg). They placed their bare feet on shaved ice for 10 minutes to reduce plantar cutaneous sensation sensitivity. The plantar skin sensation on the fifth metatarsal was measured with a set of Semmes-Weinstein monofilaments. The higher values indicate lower sensitivity and higher thresholds. The participants executed three single-leg drop landings from a 20-cm platform before (pre) and after (post) ice immersion, respectively. Dynamic stability was measured using the time to stabilization (TTS) in the anteroposterior (AP), mediolateral (ML) and vertical (V) directions by a force plate. A paired-sample t-test was used to analyze data. RESULTS: Plantar cutaneous sensation threshold (pre: 3.07±0.38 gauge, post: 4.12±0.28 gauge, p<0.001, d=3.14) significantly increased after ice immersion. TTSML was significantly decreased (pre: 3.94±0.27 s, post: 3.85±0.23 s, p=0.041), but TTSAM (pre: 4.07±0.79 s, post: 4.11±0.81 s) and TTSv (pre: 3.04±0.16 s, post: 3.11±0.53 s) had increased tendency without statistical difference (p>0.05). CONCLUSIONS: The reduced plantar cutaneous sensation through acute ice-immersion intervention could improve dynamic stability in ML among adults with CAI during single-leg drop landing.