Shoulder rotator strength and torque steadiness in athletes with anterior shoulder instability or SLAP lesion

Author(s)

Saccol, Michele Forgiarini ^[1] ; Zanca, Gisele Garcia ^[1] ; Ejnisman, Benno ^[2] ; de Mello, Marco Tulio ^[3] ; Mattiello, Stela Marcia ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Phys Therapy, BR-13560 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Paulo, Dept Orthopaed Surg & Sports Med, Sao Paulo - Brazil

^[3] Univ Fed Sao Paulo, Dept Psychobiol, Ctr Studies Psychobiol & Exercise, Sao Paulo - Brazil

• Document type: Journal article
• Source: JOURNAL OF SCIENCE AND MEDICINE IN SPORT; v. 17, n. 5, p. 463-468, SEP 2014.
• Web of Science Citations: 9

Abstract

Objectives: To investigate shoulder rotator strength and steadiness in athletes with anterior instability and superior labrum anterior posterior (SLAP) lesion. Design: Cross-sectional laboratory study. Methods: Athletes with anterior shoulder instability (instability group, n=10) and a SLAP lesion (SLAP group, n = 10) were compared with healthy athletes matched by age, anthropometrics and sport (control group for shoulder instability, n = 10 and control group for SLAP, n = 10). Torque steadiness was evaluated with three 10 s submaximal isometric contractions (35% of peak torque) with the arm at 900 of shoulder abduction and 900 of external rotation. The mean isometric torque, standard deviation and coefficient of variation were measured from the steadiness trials. To evaluate shoulder rotator strength, concentric isokinetic tests (90 degrees/s, 180 degrees/s) were performed at the 90-90 degrees position and peak torque to body mass and shoulder external to internal rotation ratio variables were analyzed. The variables were tested with the instability and control groups with respect to shoulder instability and between the SLAP and control groups for SLAP lesion using the Mann-Whitney test. Results: The SLAP group presented a higher coefficient of variation than the SLAP control group (p = 0.003). Regarding shoulder strength, the internal and external shoulder rotators were weaker in the instability group than in the instability control group (p <0.05). Conclusions: Athletes with anterior shoulder instability presented shoulder rotation weakness, while athletes with a SLAP lesion showed higher torque fluctuation during internal rotation. These results indicate that there are different alterations to strength and sensory motor control in each condition. (C) 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 09/05219-5 - Morphofunctional analysis of rotator cuff in subjects with glenohumeral instability
• Grantee: Michele Forgiarini Saccol
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 08/02076-6 - Sensory-motor control and functional torque ratios of shoulder rotation in overhead athletes with and without impingement symptoms
• Grantee: Gisele Garcia Zanca
• Support Opportunities: Scholarships in Brazil - Master