Lower Limb Kinematic Characteristics During Obstacle Step-Over Among Individuals with Retinitis Pigmentosa

Abstract

The present study investigated the characteristics of foot trajectory patterns during obstacle step-over between individuals with normal or corrected vision, and the visually impaired. The normal vision group comprised ten men with normal or corrected vision, while the visually impaired group comprised ten men with pigmentary retinal degeneration. Both groups performed two obstacle step-over conditions （heights of obstacles: 4 cm and 15 cm） from a free position. Gait parameters while stepping over the obstacle, were analyzed. The visually impaired group had significantly advanced initiation of the step-over motion, increased step length, and increased time required to complete the task in both conditions when compared to the normal vision group. Furthermore, the highest points of the leading and trailing feet while stepping over the obstacle were significantly higher in the visually impaired group, and the coefficient of effort in the visually impaired group was significantly larger than that for the normal vision group. Additionally, the visually impaired group tended to secure foot clearance mainly by hip flexion movement. These results suggested that individuals with visual impairment spend more time and effort during the obstacle step-over to ensure a safer trajectory path and a lower trip and fall risk.