Work experience mitigated age-related differences in balance and mobility during surface accommodation

Background Locomotor behavior at the roofing worksite is challenged by factors such as sloped surfaces, wind gusts and handling loads. Chronic exposure to this environment may result in enhanced locomotor strategies that are resistant to aging effects. The purpose of this study was to determine if roofers demonstrated enhanced locomotor strategies and if the strategies were maintained with age. Methods. The gait of ten younger roofers (mean age 27.2 years), eight older roofers (55.4 years), ten younger controls (25.4 years) and nine older controls (57.6 years) was examined during level gait and stepping up onto a wooden surface (0.15 in high). Subjects either carried no load, an empty box or the same box loaded to the equivalent of 5% body mass. Findings. Work by age interactions were observed for toe clearance, step width, net angular momentum of the head, arms and trunk segment and gait speed (P < 0.0001). Younger roofers demonstrated the greatest toe clearance; older roofers had a smaller lead clearance but decreased variability. Older control groups had the greatest risk of tripping due to low lead toe clearance and high variability, and were least likely to recover if they did trip due to faster gait speed and increased net angular momentum. Work experience resulted in enhanced changes in lead toe clearance and mitigated age-related changes in step width and net angular momentum. Interpretation. Challenging environments show promise for maintaining balance skills in older adults, however care should be taken when introducing inexperienced older adults to a challenging environment. (c) 2005 Elsevier Ltd. All rights reserved.