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Biomechanical analysis of personal CTS attributes.
Department of Industrial and Operations Engineering, University of Michigan, Ann Arbor, Michigan, 1978 Apr; :1-70
The importance of wrist size and the effect of high force loads on tendons were investigated in relation to carpal tunnel syndrome (CTS). The geometry of the curvature of the finger flexor tendons as they pass over the trochlea of the wrist was estimated using a relationship between the change in joint angle of the wrist and displacement of the flexor tendon to determine the radius of curvature of the tendon. Human cadaver limbs were dissected and direct measurement were made of the spatial location of the tendon. The radius of curvature of the tendon in the vicinity of the trochlea was determined by fitting polynomials to the data. The radius of curvature of the finger flexor tendons was found to range from about 0.9 to 4.0 centimeters. The radius of curvature was larger during flexion than extension. Higher force loadings on the tendon during extension and flexion of the wrist joint may be implied by a smaller radius of curvature. No predisposition of the wrist to the development of CTS was evidenced by the five bone dimensions which indicate wrist size and hand length. Intra wrist forces on the tendon increased significantly as joint thickness decreased during wrist flexion, but not during extension. Variations in wrist structure were not found to be an etiological factor in the occurrence of CTS. The authors recommend that further cadaver study be done to determine whether the values for radius of curvature can be replicated.
NIOSH-Grant; Musculoskeletal-system-disorders; Skeletal-system-disorders; Hand-injuries; Arm-injuries; Biomechanics; Ergonomics
Industrial Engineering University of Michigan 2260 G G Brown University Ann Arbor, Mich 48105
Final Grant Report
NTIS Accession No.
Department of Industrial and Operations Engineering, University of Michigan, Ann Arbor, Michigan
University of Michigan, Ann Arbor, Michigan
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division