Postural Stability and Perceived Control in Functional Performance During Occupational Precision Sewing

Precision manual work is linked to sustained postural exposure and a higher risk of work-related musculoskeletal disorders. The extent to which working posture influences functional performance via postural stability and perceived control remains underexplored in occupational settings. This study examined the effects of seated and standing working postures on physical load, mental workload, and functional task performance during occupational precision sewing.

A within-subject crossover experiment was conducted with 26 experienced sewing machine operators. Participants performed standardized sewing tasks in seated and standing postures. Outcomes included perceived physical effort (Borg CR-10), postural risk (RULA), mental workload (NASA-TLX), execution time, sewing quality, and qualitative perceptions of control and stability.

Standing posture was associated with higher lower-limb effort (p=0.010), increased postural risk (χ²=60.24, p<0.001), and higher overall mental workload (p=0.033). Sewing quality was moderately reduced in the standing condition, while execution time did not differ (p>0.05). Qualitative findings indicated that standing increased weight-bearing discomfort and postural regulation demands, whereas seated posture supported greater perceived control for precise stitching.

Working posture influenced functional performance primarily through stability and perceived control mechanisms. Sustained standing during precision work may increase musculoskeletal risk and compromise task accuracy. Well-adjusted seated workstations should be prioritized for occupational precision sewing tasks. Posture alternation strategies should be carefully managed to balance musculoskeletal load and performance quality.