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The relationship between wrist position, grasp size, and grip strength
S W O'Driscoll1, E Horii, R Ness
1Division of Orthopaedic Surgery, St. Michael's Hospital, University of Toronto, Ontario, Canada.
The Journal of Hand Surgery
|January 1, 1992
Summary
Optimal grip strength is achieved with the wrist in a specific self-selected position. Deviating from this optimal wrist posture, even slightly, significantly reduces grip strength in healthy individuals.
Area of Science:
- Biomechanics
- Human Factors Engineering
- Ergonomics
Background:
- The wrist's posture is crucial for effective grip strength.
- Understanding the optimal wrist position for maximal grip is essential for preventing injuries and optimizing performance.
Purpose of the Study:
- To investigate the optimal wrist position for maximal grip strength in healthy subjects.
- To determine the relationship between wrist deviation and grip strength.
- To assess the effect of grasp size on the self-selected wrist position.
Main Methods:
- Grip strength and wrist position were measured in 20 healthy subjects.
- Subjects adopted self-selected wrist positions and deviated wrists into flexion, extension, or radial/ulnar deviation.
- The effect of grasp size using a Jamar dynamometer was studied in 21 subjects.
Main Results:
- The self-selected optimal wrist position was 35 degrees of extension and 7 degrees of ulnar deviation.
- Grip strength significantly decreased with any deviation from the self-selected position.
- Wrist extension was inversely related to grasp size, particularly for smaller hands.
Conclusions:
- Grip strength is significantly reduced when the wrist deviates from its optimal posture.
- A minimum of 25 degrees of wrist extension is required for optimal grip strength.
- Grasp size influences self-selected wrist posture, impacting grip performance.