Physical capacity, occupational physical demands, and relative physical strain of older employees in construction and healthcare

PURPOSE: To assess age-related differences in physical capacity, occupational physical demands, and relative physical strain at a group level, and the balance between capacity and demands at an individual level, for construction and healthcare workers. METHODS: Shoulder strength, back strength, and aerobic capacity were assessed among construction (n = 62) and healthcare workers (n = 64). During a full working day, accelerometers estimated upper-arm elevation, trunk flexion, and occupational physical activity as indicators of occupational physical demands. Simultaneously, normalised surface electromyography (%sEMG(max)) of the upper trapezius and erector spinae muscles, and normalised electrocardiography (percentage heart rate reserve (%HRR)) estimated relative physical strain. Differences between younger (≤ 44 years) and older (≥ 45 years) workers, as well as the moderating effect of age on the associations between capacity and demands, were analysed per sector. RESULTS: Compared to younger workers, older workers had similar strength and lower aerobic capacity; older construction workers had similar demands while older healthcare workers had higher demands. Compared to younger workers, older employees had unfavourable muscle activity patterns; %HRR had a tendency to be lower for older construction workers and higher for older healthcare workers. Among construction workers, age moderated the associations between shoulder strength and arm elevation (p = 0.021), and between aerobic capacity and occupational physical activity (p = 0.040). Age did not moderate these associations among healthcare workers. CONCLUSIONS: In both sectors, the level of occupational physical demands and the higher relative physical strain in older employees require addressing to promote sustainable work participation among an aging population. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00420-018-1377-5) contains supplementary material, which is available to authorized users.