عنوان مقاله [English]
Background & purpose: previous studies showed that scapulohumaral rhythm is different between overhead athletes and non-athletes. The purpose of present study was to compare the selected shoulder muscles recruitment patterns among overhead athletes and non-athletes between dominant and non-dominant shoulders in external loading and unloading conditions during humeral abduction in scapular plane.
Methodology: Thirty male overhead athletes and 10 non-athletes volunteered for this quasi-experimental study. EMG data were collected using a biomonitor system (ME6000, T-16, Manufactured by Mega Electronics Ltd, Finland, sampling rate, 2000 Hz). Electromyography activity of upper, middle and lower trapezius, middle and anterior deltoid, infraspinatus, serratus anterior and latissimus dorsi collected during humeral abduction in scapular plane (0-160º in 4 seconds) in dominant and non-dominant shoulders in external loading and unloading conditions. ANOVA with repeated measures test were used to survey within and between group effects (p≤0.05).
Results: Findings indicated that external loading had significant effect on shoulder muscles recruitment patterns during humeral abduction in scapular plane (p=0.025) but, shoulder muscles recruitment patterns was similar in dominant and non-dominant shoulders (p= 0.5). Also, there was no significant difference in shoulder muscles recruitment patterns among groups during humeral abduction in scapular plane (p=0.82).
Conclusion: it seems that type of sport and dominant and non-dominant shoulders don’t have any effect on shoulder muscles recruitment pattern among handball players, tennis players, swimmers and non-athletes during arm elevation in scapular plane. These findings could be used as guidance in clinical and rehabilitation assessments.