Effects of tripping conditions and repetitions on reactive balance control during walking and carrying tasks

Falls caused by tripping during walking and load-carrying tasks remain a major source of occupational injury. This study examined the effects of tripping condition, task, and repetition on reactive balance responses. Twenty adults performed walking and carrying tasks under obstacle and cord tripping conditions across six repeated trials. Obstacle tripping produced longer recovery step times and greater recovery step lengths than cord tripping, indicating greater balance recovery demands. Carrying a 6.8-kg anterior load did not greatly impair reactive balance, although it modified repetition-related changes in recovery step length. Repeated exposure was associated with reduced recovery step length during carrying obstacle tripping and reduced trunk flexion during obstacle tripping under both walking and carrying conditions. Perceived recovery difficulty was greater during obstacle tripping, whereas perceived worry decreased across repetitions during walking. These findings indicate that reactive balance responses were mostly affected by perturbation types, while load carriage may influence repetition-related recovery stepping.