Low vision affects dynamic stability of gait

Abstract 

The objective of this study was to demonstrate specific differences in gait patterns between those with and without a visual impairment. We performed a biomechanical analysis of the gait pattern of young adults (27±13 years old) with a visual impairment (n=10) in an uncluttered environment and compared it to the gait pattern of age matched controls (n=20). Normally sighted adults were tested in a full vision and no vision condition. Differences are found in gait between both groups and both situations. Adults with a visual impairment walked with a shorter stride length (1.14±0.21m), less trunk flexion (4.55±5.14°) and an earlier plantar foot contact at heel strike (1.83±3.49°) than sighted individuals (1.39±0.08m; 11.07±4.01°; 5.10±3.53°). When sighted individuals were blindfolded (no vision condition) they showed similar gait adaptations as well as a slower walking speed (0.84±0.28ms⁻¹), a lower cadence (96.88±13.71stepsmin⁻¹) and limited movements of the hip (38.24±6.27°) and the ankle in the saggital plane (−5.60±5.07°) compared to a full vision condition (1.27±0.13ms⁻¹; 110.55±7.09stepsmin⁻¹; 45.32±4.57°; −16.51±6.59°).

Results showed that even in an uncluttered environment vision is important for locomotion control. The differences between those with and without a visual impairment, and between the full vision and no vision conditions, may reflect a more cautious walking strategy and adaptive changes employed to use the foot to probe the ground for haptic exploration.

Keywords: Locomotion, Gait, Low vision, Kinematics, Stability