Date of Graduation


Document Type


Degree Type



Statler College of Engineering and Mineral Resources


Civil and Environmental Engineering

Committee Chair

Fei Dai

Committee Member

John P. Zaniewski

Committee Member

Roger Chen

Committee Member

Scott Breloff

Committee Member

Yoojung Yoon


Construction roofers have the uppermost likelihood of developing knee musculoskeletal disorders (MSDs). Roofers spend more than 75% of their total working time being restricted to awkward kneeling postures and repetitive motions in a sloped roof setting. However, the combined effect of knee-straining posture, roof slope and their association to knee MSDs among roofers are still unknown. This dissertation aimed to provide empirical evidence of the effects of two roofing work-related factors namely, roof slope and kneeling working posture, on the development of knee MSDs among construction roofers. These two factors were assessed as potential to increase knee MSD risks in roofing by evaluating the awkward knee rotations and heightened activation of knee postural muscles that might occur in sloped-shingle installation. Moreover, a novel ranking-based ergonomic risk analysis method was developed to identify the riskiest working phase in the sloped-shingle installation operation. In addition, a data fusion method was developed for treating multiple incomplete experimental risk related datasets that would affect the accuracy of risk assessments due to human and technology-induced errors during experimental data collection.

The findings revealed that roof slope, working posture and their interaction have significant impacts on developing knee MSDs among roofers. Knees are likely to have increased exposure to MSD risks during placing and nailing shingles on sloped roof surfaces. The established data fusion method has been proven feasible in handling up to 40% missing data in MSD risk-related datasets.

The contributions lie in enhanced understanding of the physical risk exposures of roofers' knee MSDs and creation of the ranking-based ergonomic analysis method and the fusion method that will help improve the MSD risk assessment in construction. In the long run, these outcomes will help develop new knee joint biomechanical models, effective interventions, and education and training materials that will improve the workplace to promote health and safety of roofers.

Embargo Reason

Publication Pending