Related Experiment Video
Updated: May 24, 2026
09:36
Measurement of Spatial Stability in Precision Grip
Published on: June 4, 2020
Power grip force is modulated in repeated elbow movement
1Department of Health Care Sciences, School of Health Professions, UT Southwestern Medical Center at Dallas, 6011 Harry Hines Boulevard, Dallas, TX, USA. fan.gao@utsouthwestern.edu
Ergonomics
|March 20, 2012
Summary
Repeatedly performing a power grip with fast arm movements increases muscle activity and joint stiffness, potentially raising the risk of cumulative trauma disorders (CTD). Avoid combining these actions in the workplace to mitigate injury risks.
Area of Science:
- Ergonomics
- Biomechanics
- Occupational Health
Background:
- Power grip tasks are common in workplaces and often involve arm movements.
- Increased physical demand during these tasks can lead to elevated muscle activity.
- This may heighten the risk of developing repetitive musculoskeletal injuries.
Purpose of the Study:
- To quantitatively analyze how repeated elbow movements affect power grip force.
- To investigate the relationship between grip force modulation, muscle cocontraction, and the risk of cumulative trauma disorders (CTD).
Main Methods:
- Thirteen participants performed repeated arm movements at various speeds (slow, self-paced, fast) while maintaining grip forces at 20%, 40%, and 60% of maximum.
- Muscle activities of finger flexors and elbow muscles were measured.
- Grip force fluctuations and apparent joint stiffness were assessed.
Main Results:
- Increased motion rate and grip force levels significantly elevated grip force fluctuation (p < 0.01).
- Higher motion rates and force levels also led to significantly increased finger flexor muscle activity and elbow muscle cocontraction (p < 0.01).
- Apparent elbow joint stiffness significantly increased with higher motion rates and force levels (p < 0.01).
Conclusions:
- The combination of power grip and fast arm movements significantly increases muscle activity, cocontraction, and joint stiffness.
- These findings suggest a potential elevated risk for developing cumulative trauma disorders (CTD) under such conditions.
- Workplace practices should minimize the simultaneous use of power grip with rapid arm movements to reduce injury risk.
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