Do changes in hand grip strength correlate with shoulder rotator cuff function?

Area of Science:

• Orthopedics
• Sports Medicine
• Musculoskeletal Research

Background:

• Rotator cuff pathology is a leading cause of shoulder pain in primary care.
• Hand grip strength assessment is a potential, non-invasive indicator of rotator cuff function.
• Understanding the relationship between grip strength and rotator cuff strength is crucial for effective patient assessment.

Purpose of the Study:

• To investigate the correlation between hand grip strength and shoulder lateral rotator muscle strength.
• To determine if grip strength can be utilized as a functional assessment tool for the posterior rotator cuff.
• To explore this relationship across various shoulder positions.

Main Methods:

• The study included 27 healthy, physically active volunteers with no history of shoulder, upper limb, or neck injury.
• Grip strength was measured using a hand grip dynamometer.
• Lateral rotator strength was measured using a handheld dynamometer at neutral, 90° abduction, and 90° abduction with 90° external rotation.

Main Results:

• A strong positive correlation was observed between grip strength and shoulder lateral rotation strength across all tested positions.
• Correlation coefficients ranged from r=0.91 (r²=0.84) to r=0.72 (r²=0.52).
• The relationship was consistent for both left and right hands.

Conclusions:

• Grip strength demonstrates a significant correlation with shoulder lateral rotator strength.
• Grip strength assessment is a viable method for monitoring rotator cuff recruitment function.
• This simple assessment offers a potential tool for primary care evaluation of shoulder function.