Gender and body height discriminate spinal movement patterns during lifting and lowering tasks

This study aimed to explore the relationships between gender, anthropometrics, and spinal movement patterns (SMP) during lifting and lowering tasks. Thirty adults lifted and lowered a 15 kg-box using a freestyle, squat, and stoop technique. A stepwise segmentation approach, along with the timing of main inflection points of relative angles, was used to distinguish various spinal movement patterns. Temporal multi-segmental interactions were categorised, and their frequencies were analysed based on segments and lifting techniques. SMP's demonstrated varying associations with gender and anthropometric factors during lifting and lowering phases. Notably, during stoop lifting, females tended towards a bottom-up pattern, contrasting with males' preference for a simultaneous pattern. Cluster analysis highlighted the bottom-up pattern in the thoracic spine as the most prominent discriminating factor among females. This SMP categorisation method holds potential for designing tailored manual material handling strategies and re-evaluating therapeutic and exercise programs in occupational, clinical, and sport contexts.