Abstract
OBJECTIVE: The study examines temporal variations in upper-extremity musculoskeletal symptoms throughout the day, over a week and throughout the semester. METHODS: 30 undergraduates were followed in a repeated measures study throughout a semester. Upper extremity musculoskeletal symptoms data were collected on handheld computers randomly throughout the day for seven days over three data collection periods. Multilevel statistical models evaluated associations between time-related predictors and symptoms. RESULTS: In adjusted models, pain reported at baseline was associated with increased odds of experiencing both any symptoms (OR=15.64; 90% CI 7.22-33.88) and moderate or greater symptoms (OR=16.44; 90% CI 4.57-29.99). Any symptoms were less likely to be reported if responses occurred at 58-76 days (OR=0.66; 90% CI 0.49-0.86), 77-90 days (OR=0.29; 90% CI 0.20-0.42) and 91-117 days (OR=0.54; 90% CI 0.39-0.75) into the semester compared to 35-57 days. Similarly, responding after midnight was associated with greater odds of reporting moderate or greater symptoms (OR=21.33; 90% CI 6.49-65.97). There was no association observed for day of week and symptoms. CONCLUSION: This pilot work suggests upper extremity musculoskeletal symptoms exhibit temporal variations related to time of day and days into semester. Understanding the natural history of musculoskeletal symptoms and disorders is needed when designing epidemiologic research and/or intervention studies using symptom outcome measures.