Abstract
OBJECTIVES: To investigate the effects of height, surface firmness, and visual reference on standing balance in construction workers. DESIGN: Controlled laboratory study with balanced repeated measures. PARTICIPANTS: Twenty four construction workers. SETTING: Test subjects performed standing tasks at ground level as well as at 3 m and 9 m high balconies on firm or deformable surfaces with close visual references included or excluded from their visual field. METHODS: Standing balance was determined from center of pressure as measured by a force platform. Dependent variables were root mean square of sway in medial-lateral and anterior-posterior directions, area of sway, and velocity of sway. RESULTS: Heights without close visual references significantly increased all sway parameters. The effect of height in conditions without close visual references increased dramatically on deformable surfaces. CONCLUSIONS: Elevated work environments and deformable work surfaces negatively affect balance and may be associated with increased risk of fall incidents. Appropriate close visual references increase the ability to maintain balance.