Variability in risk factors for knee injury in construction

Area of Science:

• Occupational health
• Ergonomics
• Construction safety

Background:

• Knee pain is a common issue in construction trades.
• Understanding exposure to risk factors like kneeling, squatting, and load carrying is crucial for prevention.
• Previous studies may not have fully captured the variability in these exposures.

Purpose of the Study:

• To investigate the sources of variance in exposure to risk factors for knee pain among highway construction workers.
• To quantify the contributions of trade, operation, task, and individual worker to exposure variability.
• To inform the design of more accurate exposure assessment strategies for epidemiological and intervention studies.

Main Methods:

• Conducted over 15,000 discrete observations of leg postures and weights handled.
• Included 120 construction workers across five trades, nine operations, and 79 days.
• Utilized multilevel random effects models to analyze sources of variance.

Main Results:

• Construction operations and tasks explained 20% to 30% of the total variation in kneeling, squatting, and carrying loads.
• A significant unexplained component of variance suggests substantial day-to-day variability within tasks.
• Homogeneous exposure groups were difficult to define based on standard work organization.

Conclusions:

• Reliable assessment of knee exposure in construction necessitates multiple observation days to account for high intra-task and inter-task variability.
• Current organizational features of construction work do not easily define homogenous exposure groups.
• Future epidemiological and intervention studies must carefully consider these sources of variability for accurate exposure estimation.