Shoulder pain in elite swimmers: primarily due to swim-volume-induced supraspinatus tendinopathy.
OBJECTIVE
Shoulder pain in elite swimmers is common, and its pathogenesis is uncertain. HYPOTHESIS/STUDY DESIGN: The authors used a cross-sectional study design to test Jobe's hypothesis that repetitive forceful swimming leads to shoulder laxity, which in turn leads to impingement pain.


METHODS
Eighty young elite swimmers (13-25 years of age) completed questionnaires on their swimming training, pain and shoulder function. They were given a standardised clinical shoulder examination, and tested for glenohumeral joint laxity using a non-invasive electronic laxometer. 52/80 swimmers also attended for shoulder MRI.


RESULTS
73/80 (91%) swimmers reported shoulder pain. Most (84%) had a positive impingement sign, and 69% of those examined with MRI had supraspinatus tendinopathy. The impingement sign and MRI-determined supraspinatus tendinopathy correlated strongly (r(s)=0.49, p<0.00001). Increased tendon thickness correlated with supraspinatus tendinopathy (r(s)=0.37, p<0.01). Laxity correlated weakly with impingement pain (r(s)=0.23, p<0.05) and was not associated with supraspinatus tendinopathy (r(s)=0.14, p=0.32). The number of hours swum/week (r(s)=0.39, p<0.005) and weekly mileage (r(s)=0.34, p=0.01) both correlated significantly with supraspinatus tendinopathy. Swimming stroke preference did not.


CONCLUSIONS
These data indicate: (1) supraspinatus tendinopathy is the major cause of shoulder pain in elite swimmers; (2) this tendinopathy is induced by large amounts of swimming training; and (3) shoulder laxity per se has only a minimal association with shoulder impingement in elite swimmers. These findings are consistent with animal and tissue culture findings which support an alternate hypothesis: the intensity and duration of load to tendon fibres and cells cause tendinopathy, impingement and shoulder pain.
Sein
Mya Lay
ML
Orthopaedic Research Institute, University of New South Wales, St George Hospital, Australia.
Walton
Judie
J
Linklater
James
J
Appleyard
Richard
R
Kirkbride
Brent
B
Kuah
Donald
D
Murrell
George A C
GA
D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006811:Humerus / Q000293:injuries* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D016059:Range of Motion, Articular; D019534:Shoulder Impingement Syndrome / Q000209:etiology* / Q000503:physiopathology; D020069:Shoulder Pain / Q000209:etiology* / Q000503:physiopathology; D013550:Swimming / Q000293:injuries* / Q000502:physiology; D052256:Tendinopathy / Q000209:etiology* / Q000503:physiopathology; D055815:Young Adult