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Cumulative trauma disorder: skeletal muscle dysfunction.
Department of Physiology, West Virginia University, Morgantown, West Virginia 1995 Mar; :1-10
Experiments were designed to develop a reproducible technique for producing chronic strain injury to rat skeletal muscles as a model for cumulative trauma disorder (CTD), and to measure the functional outcome of repeated microtrauma in order to develop strategies and programs for its prevention. A dynamometer was designed and built to control the velocity and range of movement of the rat foot during a strain overload and test the functional outcome in terms of muscle strength, endurance, and stiffness in-vivo. Changes in the extracellular matrix and sarcolemma of skeletal muscles which could result in muscle pathology or adaptation were measured. Cumulative microtrauma was administered three times a week for 4 weeks to one leg of female rats. Muscles became myopathic after 1 month of exposure to repeated strains. The appearance of muscle pathology was related to the strain rate. Repeated high velocity strains were accompanied by myofiber heterogeneity and apparent fibrosis while low velocity strains produced muscle hypertrophy and positive adaptations. These two responses were noted in muscles commonly recruited for low level endurance activity. The authors conclude that appropriate rest periods are important for recovery from metabolic fatigue and repair of tissue damage.
NIOSH Grant; Musculoskeletal system disorders; Muscle function; Repetitive work; Laboratory animals; Cumulative trauma disorders
Physiology West Virginia University 3051 Health Sciences North Morgantown, WV 26506
Final Grant Report
NTIS Accession No.
Department of Physiology, West Virginia University, Morgantown, West Virginia
West Virginia University, Morgantown, West Virginia
Page last reviewed: April 9, 2021
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