Assessment of physical exposures and comparison of exposure definitions in a repetitive sawmill occupation: Trim-saw operator

Article type: Research Article

Authors: Jones, Troy | Kumar, Troy

Affiliations: University of Alberta, Faculty of Rehabilitation Medicine, Department of Physical Therapy, Edmonton, Canada

Note: [] Address for correspondence: Troy Jones, 3-74 Corbett Hall, University of Alberta, Edmonton, Alberta, Canada T6G 2G4. Tel.: +1 780 492 7187; Fax: +1 780 492 1626; E-mail: [email protected]

Abstract: This paper describes the physical exposures required to perform a sawmill job associated with a high incidence of upper extremity musculoskeletal injury. Exposure variables are described by multiple posture, exertion and frequency definitions and the comparability of those definitions are examined. Effective industrial prevention efforts require an accurate assessment of risk. Surface electromyography and electrogoniometry were used to quantify the physical exposures of 29 trim-saw operators in four sawmill facilities. Average wrist ranges of motion of 32, 57 and 58 degrees in wrist radial/ulnar deviation, flexion/extension and pronation/supination respectively were required to perform the job. Defining wrist range of motion by the peak postures observed versus those required to perform the primary task resulted in significantly different ranges of motion (p<0.05). Job performance required an average of 33% of maximum voluntary contraction. Repetitions per day ranged from 3,549 to 14,460. Percentage of maximum voluntary contraction was not associated with psychophysical measures of exertion.

Keywords: Field study, job analysis, physical ergonomics

Journal: Work, vol. 28, no. 2, pp. 183-196, 2007