Effects of backpack load on stair gait in young male adults

Abstract

Backpack load has been found to be a potential risk factor for accidental falls during level walking. Stairs are considered one of the most hazardous locations in occupational settings, and falls often occur on stairs. However, how backpack load affects stair gait in young adults was still unknown. The objective of the present study was to reveal the effects of backpack load on stair gait in young male adults. Thirty male adults participated, and completed three ascent and three descent trials in the no load, low load, and high load conditions, respectively. Four categories of dependent measures were used to characterise stair gait, including lower limb and trunk kinematics, foot clearance measures, spatial-temporal gait parameters, and postural stability measures. We found that participants adjusted their postural control to compensate for the disturbance caused by backpack load and maintain their postural stability as in the no load condition. However, loaded participants may encounter increased risk of stair contact during ascent and increased risk of over-stepping during descent when passing over a step. These findings support that backpack load could be a risk factor for stair falls and imply that loaded people should pay more attention to the step when passing over it. Relevance to industryFindings from this study could aid in developing instructions for safe stair negotiation in occupational settings.