Determination of the ratio between glenohumeral elevation and scapular tilt during arm movement in subjects without shoulder pain

Abstract

The scapulohumeral rhythm is commonly described considering the glenohumeral elevation and scapular upward rotation. Studies describing the scapulohumeral rhythm considering the other scapular movements in asymptomatic subjects are scarce. This information can help clinicians to perform a more comprehensive evaluation and plan more specific treatment protocols. The purpose of the present study will be to determine the relationship between glenohumeral joint motion related to scapular posterior tilt. One-hundred subjects with no shoulder pain will participate in this study. The scapular and humeral kinematics will be evaluated through an electromagnetic tracking device. The subjects will perform 3 repetitions of elevation and lowering of the arm in sagittal plane and the average of the repetitions will be used to data analysis. The statistical analysis will depend of the data normality tested by Kolmogorov-Smirnov test. The data analysis will be done using the means of the arm motion in the sagittal plane. For the scapulohumeral rhythm will be used a repeated-measures 2-way ANOVA, or its non-parametric correspondent, to verify interval (30°- 60°, 60°- 90°, 90°- 120°, 120° -90°, 90°- 60°, 60°- 30°) x phase interaction (elevation and lowering) or main effects of interval or phase. The significance level will be established in 5%. (AU)