Abstract: The shoulder region has the highest incidence of acute injuries in the sport of surfing. Little is known about the strength profile at the shoulder in a surfing cohort. The primary aim of this study was to establish the reliability of a rotator cuff strength testing procedure for surfers with a secondary aim of providing a profile of internal and external rotation strength in a competitive surfing cohort. Shoulder internal rotation and external rotation isometric strength was measured using a hand-held dynamometer in 13 competitive surfers. Intra-class coefficient values ranged from 0.97 to 0.98 for intra-rater reliability and were lower for inter-rater reliability ranging from 0.80 to 0.91. Internal rotation strength was greater than external rotation strength bilaterally (dominant, p = 0.007, non-dominant, p < 0.001). No differences (p < 0.79) were found in internal rotation strength between the dominant and non-dominant arms. External rotation strength was weaker on the non-dominant arm compared with the dominant arm (p < 0.02). The non-dominant arm external rotation to internal rotation ratio (0.82 ± 0.15) was lower (p = 0.025) than the dominant arm (0.88 ± 0.14). The current procedure is reliable with the same clinician, and results indicate musculature asymmetry specific to the external rotators.
Objective: To establish the reliability of a rotator cuff strength testing procedure for surfers with the secondary objective of providing an internal and external rotational force profile in a cohort of surfers.
Methods: The isometric strength of shoulder internal rotation and external rotation was measured using a hand dynamometer in 13 competitive surfers.
Results: Intra-class coefficient values ranged from 0.97 to 0.98 for intra-examiner reliability and were lower for inter-examiner reliability, ranging from 0.80 to 0.91. The internal rotation force was greater than the external rotation force bilaterally. No differences in internal rotation force were found between dominant and non-dominant arms. The external rotation force was weaker in the non-dominant arm compared to the dominant arm. The external rotation rate of the non-dominant arm for the internal rotation (0.82 ± 0.15) was lower (p = 0.025) than the dominant arm (0.88 ± 0.14).
Conclusion: The current procedure is reliable and the results indicate asymmetry of the external rotator muscles.
SID opinion: 🤙🤙🤙. Important work for determining shoulder measurement parameters, since this joint is one of the most affected in surfing.
SID Tip: Always maintain rotator cuff muscle balance to prevent injury to the rotator cuff.