Effects of reduced plantar cutaneous sensation on static postural control in individuals with and without chronic ankle instability

Abstract

Objectives: The purpose of this study was to determine how reduced plantar cutaneous sensation influences static postural control in individuals with and without CAI.

Design: A case-control study design.

Methods: Twenty-six individuals with self-reported CAI and 26 matched healthy controls participated in this study. The plantar aspect of the participants' foot was then submersed in ice water (0°C) for 10min to reduce plantar sensation. Before and after the cooling procedure, plantar cutaneous sensation thresholds and single leg balance with eyes open and closed were assessed.

Results: Significantly, higher scores were observed in both groups after ice water submersion (p<0.001) indicating a significant reduction in the plantar cutaneous sensitivity after the cooling procedure. In single limb balance with eyes open, there were significant intervention main effects for the TTB ML mean (p<0.001), TTB AP mean (p=0.035) and TTB ML SD (p=0.021); indicating postural control improvement in both groups post-cooling. In single limb balance with eyes closed, Group×Intervention interactions were observed for the TTB AP mean (p=0.003) and TTB AP SD (p=0.017); indicating postural control deficits in CAI group post-cooling, but no changes in the control group.

Conclusions: The main finding of this study was that reduced plantar cutaneous sensation induced by an ice submersion procedure caused eyes closed postural control impairments in those with CAI but not healthy controls. The present investigation demonstrated that the ability to dynamically reweight among sensory inputs to maintain postural stability appears to be diminished in CAI patients compared to healthy controls.

Keywords: Cooling; Light touch; Sensory reweighting; Single leg balance; Time-to-boundary.