An ergonomic evaluation of manual Cleco plier designs: effects of rubber grip, spring recoil, and worksurface angle.

The present study evaluated two design modifications (rubber grip and torsion spring) to the conventional manual Cleco pliers by electromyography (EMG), hand discomfort, and design satisfaction. This study also surveyed workers' satisfaction with selected design features of the pliers for ergonomic improvement. A two-way (plier design x worksurface angle) within-subject (nested within gender and hand size) design was employed. Eleven workers simulated the plier task in an adjustable workstation for different plier designs and worksurface angles (0 degrees , 60 degrees , and 90 degrees ). Lower EMG values were obtained for the pliers with rubber grip and at 60 degrees of worksurface angle. EMG values varied significantly between the participants, but showed low correlations (Spearman's rank correlation = -0.27 approximately -0.58) with their work experience with the pliers. The hand discomfort and design satisfaction evaluations identified that the grip span (max = 14.0 cm) and grip force requirement (peak = 220.5 N) of the current pliers need ergonomic modification. The present study shows the needs of both the ergonomic design of a hand tool and the training of a proper work method to control work-related musculoskeletal disorders at the workplace.