Infrared thermography reveals effect of working posture on skin temperature in office workers.

INTRODUCTION: Musculoskeletal symptoms related to using traditional computer workstations are common. Quantitative methods for measuring muscle stress and strain are needed to improve ergonomics of workstations. We hypothesize that infrared thermography (IRT) is suited for this purpose.

METHODS: This hypothesis was evaluated by estimating muscle activity in upright and traditional working postures with IRT and surface electromyography (sEMG). IRT and sEMG measurements were conducted in 14 female participants with both working postures. First, measurements with the traditional posture were performed. Later, participants had 1 month to adjust to the upright working posture before repeating the measurements. IRT images were acquired before and after a full working day, with sEMG recordings being conducted throughout the measurement days. Participants evaluated their neck pain severity using neck disability index (NDI) questionnaires before the first and after the second measurement day.

RESULTS: Spatial variation in upper back temperature was higher (p = 0.008) when working in traditional posture and the upright working posture reduced (p < 0.05) upper back muscle activity. The NDI was significantly lower (p = 0.003) after working in the upright posture.

CONCLUSION: IRT was found suitable for evaluating muscle activity and upright working posture to reduce the NDI and muscle activity in the upper back.