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The effect of tool handle shape on hand muscle load and pinch force in a simulated dental scaling task.
Dong H; Loomer P; Barr A; Laroche C; Young E; Rempel D
Appl Ergon 2007 Sep; 38(5):525-531
Work-related upper extremity musculoskeletal disorders, including carpal tunnel syndrome, are prevalent among dentists and dental hygienists. An important risk factor for developing these disorders is forceful pinching which occurs during periodontal work such as dental scaling. Ergonomically designed dental scaling instruments may help reduce the prevalence of carpal tunnel syndrome among dental practitioners. In this study, eight custom-designed dental scaling instruments with different handle shapes were used by 24 dentists and dental hygienists to perform a simulated tooth scaling task. The muscle activity of two extensors and two flexors in the forearm was recorded with electromyography while thumb pinch force was measured by pressure sensors. The results demonstrated that the instrument handle with a tapered, round shape and a 10 mm diameter required the least muscle load and pinch force when performing simulated periodontal work. The results from this study can guide dentists and dental hygienists in selection of dental scaling instruments.
Biological-effects; Dentistry; Dentists; Engineering; Ergonomics; Exposure-assessment; Exposure-levels; Exposure-methods; Hand-injuries; Hand-tools; Medical-monitoring; Musculoskeletal-system; Musculoskeletal-system-disorders; Physiological-effects; Physiological-measurements; Physiological-response; Risk-analysis; Risk-factors; Statistical-analysis; Surface-properties; Author Keywords: Dentistry; Hand tool; Electromyography
David Rempel, MD, MPH, Division of Occupational Medicine, Department of Medicine, University of California, San Francisco, 1301 South 46th St., Building 163, Richmond, CA 94804
Issue of Publication
University of California, School of Public Health, Los Angeles, CA