A methodology for documenting hand positions and forces during manual work.
Armstrong-TJ; Chaffin-DB; Foulke-JA
J Biomech 1979 Feb; 12(2):131-133
A low cost method has been devised for estimating the frequencies that various hand positions and the corresponding hand forces used for certain manual jobs. A super 8 millimeter motion picture camera was used at four frames per second to document the positions of the hands of the worker. The film was then reviewed frame by frame through several work cycles. Hand forces were estimated from the integrated forearm and over the medial epicondyle. A ground electrode was attached to the lateral epicondyle. A fixture was developed to facilitate determination of the relationship between hand force and position. The calibration device consisted of two handles held apart by springs which can be stretched to produce desired force levels. The subjects pinched the handles together with the desired hand position until they nearly touched while the corresponding integrated electromyogram level was recorded. A calibration plot was made for each hand position of each subject. This methodology could be used for other parts of the body as well. According to the authors, such a technique may help in industrial engineering, occupational therapy and physical education.
NIOSH-Publication; NIOSH-Grant; Musculoskeletal-system-disorders; Human-factors-engineering; Ergonomics; Biomechanics; Measurement-equipment
Industrial & Operations Engr University of Michigan 2260 G G Brown Laboratory Ann Arbor, Mich 48109
Journal of Biomechanics
University of Michigan at Ann Arbor, Ann Arbor, Michigan