Trunk muscle coactivation. The effects of load asymmetry and load magnitude

Steve Lavender, Gunnar B J Andersson, Yang Hwei Tsuang, Ali Hafezi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)

Abstract

The present investigation describes the cocontraction of eight trunk muscles during the application of asymmetric loads to the torso. External moments of 10, 20, 30, 40, and 50 Nm were applied to the torso via a harness system. The direction of the applied moment was varied by 30 degree increments to the subjects' right side between and including sagittally symmetric orientations front and rear. Surface electromyography (EMG) was used to monitor the activities of the left and right Latissimus Dorsi, Erector Spinae, External Oblique, and Rectus Abdominus in 10 subjects. Analysis of Variance (ANOVA) procedures showed significant interactions between the moment magnitude and direction factors for 7 of the eight muscles. Further analyses were employed to determine which muscles were 'active' for each moment direction. This allowed the changes in muscle coactivation to be described as moment magnitudes and directions were varied.

Original languageEnglish
Title of host publicationProceedings of the Human Factors Society
PublisherPubl by Human Factors Soc Inc
Pages738-742
Number of pages5
Volume1
Publication statusPublished - 1991
Externally publishedYes
EventProceedings of the Human Factors Society 35th Annual Meeting Part 1 (of 2) - San Francisco, CA, USA
Duration: Sep 2 1991Sep 6 1991

Other

OtherProceedings of the Human Factors Society 35th Annual Meeting Part 1 (of 2)
CitySan Francisco, CA, USA
Period9/2/919/6/91

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ASJC Scopus subject areas

  • Engineering(all)

Cite this

Lavender, S., Andersson, G. B. J., Tsuang, Y. H., & Hafezi, A. (1991). Trunk muscle coactivation. The effects of load asymmetry and load magnitude. In Proceedings of the Human Factors Society (Vol. 1, pp. 738-742). Publ by Human Factors Soc Inc.