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Updated: Jul 11, 2026
10:41
Method to Measure Tone of Axial and Proximal Muscle
Published on: December 14, 2011
Neuromuscular response to cyclic lumbar twisting.
Li Li1, Nirav Patel, Deborah Solomonow
1Department of Kinesiology, Louisiana State University, Baton Rouge, Louisiana, USA.
Human Factors
|October 6, 2007
Summary
Cyclic twisting motion alters trunk muscle activity, potentially causing neuromuscular compensation for lumbar spine soft tissue damage. This research aids understanding of low back disorder risks in physically demanding jobs.
Area of Science:
- Biomechanics
- Occupational Health
- Musculoskeletal Disorders
Background:
- Repetitive occupational twisting is a risk factor for musculoskeletal disorders.
- Lack of biomechanical and physiological evidence for this risk.
Purpose of the Study:
- Investigate the effects of 10-minute cyclic twisting on abdominal and back muscle activity.
- Provide biomechanical insights into work-related musculoskeletal disorders.
Main Methods:
- Recorded trunk muscle electromyography (EMG) during 10-minute continuous lumbar cyclic twisting.
- Measured maximal isometric twist torque before and after the exercise.
Main Results:
- Left posterior muscles showed decreased integrated EMG, while right posterior muscles increased.
- Abdominal muscles showed no significant change during exercise, but increased effort post-exercise.
- Decreased left twisting torque correlated with increased antagonist coactivity in right posterior muscles.
Conclusions:
- Muscle activity changes suggest neuromuscular compensation for lumbar soft tissue laxity and microdamage.
- Findings enhance understanding of low back disorder risks from cyclic lateral twisting in labor-intensive occupations.
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