GROUPEMENT D’ISOCINETISME BELGE ET LUXEMBOURGEOIS.
5e Journée Belge
Campus ERASME - Bruxelles
Isocinétisme et techniques d’évaluation de la fonction musculaire
ISOKINETIC SCAPULAR MUSCLE PERFORMANCE IN OVERHEAD ATHLETES WITH AND WITHOUT IMPINGEMENT SYMPTOMS
A. M. Cools1, PT, PhD; E. Witvrouw1, PT, PhD; N. Mahieu1, PT, L A Danneels1, PT, PhD
1 Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University Hospital, Ghent, Belgium
Objective: to compare the isokinetic muscle performance of the scapular muscles between overhead athletes with impingement symptoms and uninjured overhead athletes and to identify strength deficits in the patient population.
Design and Setting: A repeated measures analysis of variance with one within-subject factor (side) and one between-subject factor (group) was used to compare strength values and agonist/antagonist ratios across sides and across groups.
Subjects: Thirty overhead athletes with chronic shoulder impingement symptoms and 30 overhead athletes without a history of shoulder pain participated to the study.
Measurements: Isokinetic strength values were measured during a linear protraction-retraction movement in the scapular plane at two velocities (12.2 cm/sec and 36.6 cm/sec). Protraction/retraction ratios were calculated for both velocities.
Results: Overhead athletes with impingement symptoms show decreased force output/body weight at both velocities in the protractor muscles on the injured side compared to the non-injured side (-13.7% at slow velocity, -15.5% at high velocity) and compared to the control group, measured at high velocity (-20.7%). On both sides, the patient group has significantly lower protraction/retraction ratios compared to the control group, measured at slow velocity (non-dominant: -11%, dominant: -13.7%).
Conclusions: Overhead athletes with impingement symptoms demonstrate strength deficits and muscular imbalance in the scapular muscles compared to non-injured athletes.
Key words: Scapulothoracic dysfunction, impingement, muscle imbalance, isokinetics, overhead athletes