Understanding anthropometric characteristics associated with performance in manual lifting tasks
Manual lifting is an essential military job task and is commonly linked to occupational injury. Methods to reduce injury risk focus on ensuring that employees have the requisite physical capacity to safely conduct critical job tasks. The aim of this study was to investigate which anthropometric characteristics are associated with lifting performance to inform targeted training programs for job critical lifting tasks. Sixty-three (42 males and 21 females) participants conducted three maximal lifts to a platform (pack lift to 1.5 m, box lift to 1.3 m and box lift to 1.5 m). A dual-energy x-ray absorptiometry scan was used to quantify anthropometric characteristics (body-region specific lean mass and fat mass). While anthropometric measures were strongly associated with each other, multivariable linear regression revealed that a significant proportion of the total variation in lifting performance in each of the three tasks was explained by upper arm lean mass (pack lift: β = 5.42, p<0.001; box lift 1.3 m: β = 5.64, p<0.001; box lift 1.5 m: β = 7.00, p<0.001). Leg lean mass also significantly contributed to the variation of pack lift performance (β = 0.93, p=0.01). When controlling for key anthropometric characteristics in these three tasks, separate analyses showed no significant effect of sex or stature on lift performance. These results suggest that the perceived limitations of stature and sex may be overcome by targeted training programs to improve specific physical characteristics associated with lifting performance.