Effect of age and visual contrast on gait during obstacle negotiation

Background: Obstacle avoidance and negotiation may pose significant difficulties for older people. Of particular interest is the fluency with which they can negotiate obstacles which contrast poorly with their surroundings. Methods: Two groups of healthy subjects, one young group of mean age 22 years and an older group of mean age 73 years, were tested while walking at a preferred and a fast walking speed under conditions of high and low contrast obstacle. Data were collected using a video-camera to derive values for step length, duration and velocity while subjects ambulated over a 20m track and stepped on to and over a low wooden block. Results: In essence, there was no difference between these young and old subjects in their gait strategies nor in the fluency with which they approached the obstacle. Older subjects did, however, walk slower than younger subjects at the "fast" pace. The subjects did not appear to be influenced by the contrast of the obstacle with its surroundings. Conclusions: Healthy older subjects do not show any inherent loss of fluency or hesitation in negotiating a simple obstacle, irrespective of the contrast of the obstacle with its surroundings.