Identifying Potentially Risky Phases Leading to Knee Musculoskeletal Disorders during Shingle Installation Operations

Abstract

Repeated and prolonged awkward kneeling can result in musculoskeletal disorders (MSD) in construction roofers. However, a task-specific risk assessment for roofers’ knee injuries is still missing in the literature. This study identified a ranking-based ergonomic method for suggesting potentially risky phases that may increase knee MSD risk during shingle installation operations. On a slope-adjustable wooden platform in a laboratory setting, nine subjects performed shingle installations that included seven phases: (1) reaching for shingles, (2) placing shingles, (3) grabbing nail gun, (4) moving to first nailing position, (5) nailing shingles, (6) replacing nail gun, and (7) returning to upright position. Flexion, abduction, adduction, and internal and external knee rotations were measured to assess relative risks of these phases by ranking them with a scoring model. The ranking results revealed that the phases of placing shingles and nailing shingles lead to the most knee MSD risk exposure, and awkward flexion, abduction, and adduction involved in these phases can significantly contribute to the potential knee MSD risk measurement. By using the ranking-based method, this study suggested that certain phases of the shingle installation process may increase knee MSD risk, which is useful for developing effective interventions to reduce knee injury risk exposures from roof shingle installation.