Short-term changes in upper extremity dynamic mechanical properties associated with power hand tool use.
Radwin-RG; Sesto-ME; Richard-TG
Human Factors and Ergonomics Society 47th Annual Meeting. Santa Monica, CA: Human Factors and Ergonomics Society, 2003 Oct; :1261-1264
This study investigated the relationship between repetitive eccentric exertions in power hand tool operation and upper limb mechanical properties including stiffness and inertial mass, and physiologic measures including localized pain, discomfort, and swelling. Tool parameters, including peak torque (3Nm and 8Nm) and torque build up time (50ms and 250ms), were controlled in a full-factorial design. Twenty-nine participants were randomly assigned to one of the four conditions and operated a pistol grip nut runner four times per minute for one house in the laboratory. And average decrease in stiffness (48%) and mass moment of inertia (80%) of the upper limb was observed immediately following pistol grip nut runner operation. A previously developed dynamic tool operator model was used to predict resulting handle force and displacement, and the conditions associated with the greatest handle force and displacement demonstrated the greatest decrease in mechanical stiffness and inertial mass, and the greatest increase in localized discomfort.
Hand-tools; Tools; Physiological-factors; Laboratory-testing; Biomechanical-modeling; Biomechanics; Ergonomics; Human-factors-engineering; Worker-health; Work-performance; Work-operations; Work-practices; Work-environment; Workplace-studies; Workplace-monitoring; Statistical-analysis; Posture; Body-mechanics; Muscles; Musculoskeletal-system; Musculoskeletal-system-disorders; Muscular-disorders; Muscle-tension; Muscle-stress; Muscle-physiology; Muscle-function; Muscle-contraction; Injuries; Injury-prevention; Power-tools; Cumulative-trauma-disorders; Cumulative-trauma; Repetitive-work
Disease and Injury: Musculoskeletal Disorders of the Upper Extremities
Human Factors and Ergonomics Society 47th Annual Meeting
University of Wisconsin, Department of Biomedical Engineering, Madison, WI