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Electromyographic patterns associated with a carpet installation task.

Bhattacharya A; Ramakrishanan HK; Habes D
Ergonomics 1986 Sep; 29(9):1073-1084
The electromyographic activity patterns associated with typical static postures and dynamic activities of the carpet installation task were determined in eight male subjects who performed the act of carpet stretching using a carpet layer's knee kicker. The isometric muscle torque values for the knee flexors were comparable to those reported by others, but the values for knee extensors were lower, which was partially due to the lower body weight of the subjects tested (64 kilograms versus 82 kilograms). All subjects showed negligible electromyographic activity when postured statically on hands and knees, while for the other static knee kicking postures, the results varied according to the muscles. For the beginning knee cycle, the activity was present in the knee extensors and flexors and the shoulder flexors; for the middle kick cycle posture, the knee and shoulder flexors were dominant. This pattern prevailed for the shoulder flexors and knee extensor during the final impact phase, while the knee flexors' activity declined at the point of impact. With small changes, the same pattern prevailed during dynamic activity. The knee extensors were most active and minor shoulder flexor activity was also present in some subjects during the beginning kick cycle; in the middle kick phase, the knee flexors and the shoulder showed some activity; just before the impact phase, the knee and shoulder flexors were most active; only the shoulder flexors remained activated during the post impact phase. The activity of the groups of muscles tested was present for only a fraction of the kicking cycle. The authors conclude that the results support the recommendation that forward body movement post impact phase be minimized in order to reduce excessive activity of the shoulder flexors.
NIOSH-Author; Ergonomics; Task-performance; Electrophysiological-measurements; Musculoskeletal-system; Muscle-stress; Physiological-stress; Humans
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Journal Article
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Musculoskeletal Disorders of the Upper Extremities; Disease and Injury; Musculoskeletal-system
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Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division