Background: Shoulder pain as a result of rotator cuff pathology is one of the most common musculoskeletal complaints presenting within primary care. Assessment of hand grip strength has been proposed as an indicator of rotator cuff function. This experimental study assessed the relationship between grip strength and shoulder lateral rotator muscle strength in a number of different shoulder positions, aiming to investigate whether such a relationship existed and whether grip strength could be used as a functional assessment tool for the posterior cuff.
Methods: Twenty-seven healthy, physically active, volunteers (19 males, eight females) with no history of shoulder, upper limb or neck injury comprised the study group. The mean (SD) age was 19.8 (5.7) years (range 18 years to 23 years). Grip strength (measured with hand grip dynamometer) and lateral rotator strength (measured with a hand held dynamometer) was measured at neutral, 90° abduction, and 90° abduction with 90° external rotation.
Results: The correlation between grip strength and shoulder lateral rotation strength ranged between r = 0.91 (r (2 )= 0.84) and r = 0.72 (r (2 )= 0.52) across all positions.
Conclusions: A strong correlation between grip strength and lateral rotator strength was shown at all positions for both left and right hands, suggesting that assessment of grip strength could be used as a rotator cuff monitor of recruitment function.
Keywords: hand grip; lateral rotator strength; rotator cuff; shoulder.