Comparison of gait velocity and center of mass acceleration under conditions of disrupted somatosensory input from the feet during the navigation of obstacles in older adults with good and poor visual acuity

Abstract

ObjectivesTo investigate the effects of good binocular visual acuity (GBVA) versus poor binocular visual acuity (PBVA), gait velocity and center of mass (COM) acceleration were evaluated in elderly individuals under three conditions, including the navigation of obstacles while walking with altered sensory conditions in the feet. MethodsNineteen elderly Korean women from community housing were enrolled in this study; nine participants had a binocular visual acuity (BVA) that was equal to or less than 0.4 logarithm of the minimum angle of resolution (logMAR), and 10 participants had a BVA that was equal to or greater than 0.3 logMAR. Participants were fitted with an accelerometer over the L3 spinal process and then walked on a GAITRite® system at a self-selected speed under three different conditions (barefoot, wearing mountain socks, and stepping over obstacles while wearing mountain socks). ResultsThe velocity of the GBVA group was significantly higher than was that of the PBVA group whereas the COM acceleration of the GBVA group was significantly lower than was that of the PBVA group. Both groups demonstrated significant differences in velocity and under the three experimental conditions and PBVA differed significantly under conditions 1 and 3 and under conditions 2 and 3. ConclusionsThese findings suggest that visual acuity (VA) in the elderly influences dynamic balance and gait velocity. Additionally, elderly participants with PBVA exhibited a greater sensitivity to altered sensory input, especially distorted sensory input from the feet in the presence of obstacles. Thus, elderly individuals with PBVA may require balance and gait training in diverse environments, including those involving the navigation of obstacles, to reduce the likelihood of falling.