On the relationship between discrete and repetitive lifting performance in military tasks

Military manual handling requirements range from discrete lifts to continuous and repetitive lifting tasks. For the military to introduce a discrete lifting assessment, the assessment must be predictive of the various submaximum lifting tasks personnel are required to perform. This study investigated the relationship between discrete and repetitive military lifting to assess the validity of implementing a discrete lifting test. Twenty-one soldiers from the Australian Army completed a whole-body box-lifting assessment as a one repetition maximum (1RM) and a series of submaximal lifting repetitions (% 1RM). Performance was measured between the number of lifting repetitions that could be performed at different intensities between 58 and 95% 1RM. A strong curvilinear relationship existed across the entire submaximal lifting range (r = 0.72, p ≤ 0.05). The model developed demonstrated a low predictive error (standard error of the estimate = 7.2% 1RM) with no differences detected in the relationship when comparing individuals of high and low strength. Findings support the use of a discrete functional lifting assessment in providing coverage of a broad range of military lifting tasks. Parallels can be drawn between the trend reported in the current study and weight-training exercises reported in the literature.