Exposure to Regular Sit-stand Changes During Office Work Changes Limb Posture

Sixteen full-time office-based workers were exposed to extended periods working with regularly sit-stand changing table surface. The angular adduction and flexion deviations of upper arms (mousing and keying), thighs and shins were measured with 2-D inclinometers and average value calculated over one hour. Comparing average segmental deviation from standing neutral showed significant variations across the study population. Mousing arm was affected by exposure, reducing average deviation significantly from Pre to Post exposure to regular sit-stand changes. Only right shin adduction varied significantly across Pre, Post and 0% standing conditions, whereas more lower limb segment deviations changed significantly across the different standing durations. Left (but not right) thigh adduction and flexion deviations varied significantly across sit-stand conditions varying from 0% to 50% standing. Flexion of both right and left shins varied significantly, but only right shin adduction varied significantly across these same sit-stand conditions. Considering Pre-Post, Pre-Post-0% standing and five alternating sit-stand periods, shin flexion and left thigh abduction conditions significantly varied but differently. The greatest number of significant segmental angular variations occurred when considering 0% to 50% standing, although those have been ignored by previous studies which report only upper body and trunk posture angles.