Occupational physical behaviors and knee pain among eldercare workers: A prospective accelerometer study

OBJECTIVE: The aim of this study was to explore the prospective association between compositions of accelerometry-measured occupational physical behaviors and the risk of knee pain among eldercare workers.

METHODS: We performed a prospective study among 377 eldercare workers employed across 20 Danish nursing homes. Occupational physical behaviors were measured using thigh-worn accelerometers over 1-4 working days. Workers reported intensity of and days with knee pain in a questionnaire at baseline and after one year. We explored associations between compositions of occupational physical behaviors [ie, sedentary, standing, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA)] and knee pain, adjusting for potential confounders.

RESULTS: No significant associations were found. Trends were found for increased occupational time spent in MVPA and decreased risk of days with knee pain [relative risk (RR) 0.58, 95% confidence interval (CI) 0.32-1.05, P=0.07] in main analyses, and for decreased risk of knee pain intensity among non-knee pain cases (RR 0.36, 95% CI 0.12-1.13, P=0.08) in sensitivity analyses.

CONCLUSIONS: No significant associations were found between baseline occupational physical behaviors and knee pain at one-year follow-up. However, a non-significant trend suggested that increasing occupational MVPA might be associated with reduced risk of knee pain at follow-up, though studies with larger samples are needed to confirm this finding.