Infraspinatus strength assessment before and after scapular muscles rehabilitation in professional volleyball players with scapular dyskinesis.
OBJECTIVE
This study tested the hypothesis that infraspinatus strength in professional volleyball players can be assessed with the scapula free (infraspinatus strength test, IST) and with the scapula retracted (infraspinatus scapula retraction test, ISRT) before and after scapular musculature training.


METHODS
A prospective study was performed in 31 professional volleyball players. Isometric strength (kg) of the infraspinatus with IST and with ISRT was recorded by a handheld dynamometer and compared with the values found after 3 and 6 months of rehabilitation. Magnetic resonance imaging was performed to exclude articular and cuff pathology. Pain scores were assessed using a visual analog scale.


RESULTS
The mean increase in the force values of IST was statistically significant after 3 months (P < .01) and 6 months (P < .001) of rehabilitation. The mean difference between IST and ISRT decreased from 4.72 ± 0.007 before rehabilitation to 1.2 ± 0.26 at 3 months and to 0.4 ± 0.006 at 6 months. The mean score for pain was 2.4 ± 1.8 at 3 months and 2.6 ± 1.4 at 6 months.


CONCLUSIONS
Acquired scapular dyskinesis in overhead athletes can lead to the rotator cuff weakness. Inhibition due to pain and the negative biomechanic effect of scapular dyskinesis results in specific infraspinatus dysfunction that arise with the ISRT.


CONCLUSIONS
ISRT is practical and consistent to assess the infraspinatus strength in overhead athletes with scapular dyskinesis. A functional rehabilitation protocol, designed to restore scapular muscles balance and shoulder mobility, is essential in the training program to prevent shoulder dysfunction and improve sports performance.
Merolla
Giovanni
G
Unit of Shoulder and Elbow Surgery, D. Cervesi Hospital, Cattolica, Italy. gmerolla@shouldertech.it
De Santis
Elisa
E
Sperling
John W
JW
Campi
Fabrizio
F
Paladini
Paolo
P
Porcellini
Giuseppe
G
D020820:Dyskinesias / Q000175:diagnosis / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D053580:Muscle Strength; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000503:physiopathology; D011446:Prospective Studies; D012540:Scapula; D012782:Shoulder / Q000502:physiology*; D054798:Volleyball; D055815:Young Adult