Asymmetric Resting Scapular Posture in Healthy Overhead Athletes

Abstract

Context: Observation of the scapular posture is one of the most important components of the physical examination in overhead athletes. Postural asymmetry is typically considered to be associated with injuries. However, asymmetry in the overhead athlete's scapula may be normal due to the dominant use of the limb.Objective: To quantify the differences in resting scapular posture between the dominant and nondominant sides in 3 groups of healthy overhead athletes (baseball pitchers, volleyball players, and tennis players) using an electromagnetic tracking device.Design: Cross-sectional design. Setting: University-based biomechanics laboratory. Patients or Other Participants: A total of 43 players participated, including 15 baseball pitchers, 15 volleyball players, and 13 tennis players. All participants were healthy college-aged men.Intervention(s): Bilateral 3-dimensional scapular kinematics with the arm at rest were measured using an electromagnetic tracking device.Main Outcome Measure(s): Bilateral scapular position and orientation were measured. Between-groups and between-sides differences in each variable were analyzed using separate analyses of variance.Results: In tennis players, the scapula was more protracted on the dominant side than on the nondominant side (P , .05). In all overhead athletes, the dominant-side scapula was more internally rotated (P 5 .001) and anteriorly tilted (P 5 .001) than the nondominant-side scapula was.Conclusions: The dominant-side scapula of the overhead athletes was more internally rotated and anteriorly tilted than the nondominant-side scapula. The dominant-side scapula of the tennis players was more protracted than that on the nondominant side. Clinicians evaluating overhead athletes need to recognize that scapular posture asymmetry in unilateral overhead athletes may be normal. Our results emphasize the importance of the baseline evaluation in this population in order to accurately assess pathologic change in bilateral scapular positions and orientations after injury.

Reliability of Scapular Classification in Examination of Professional Baseball Players

“…We used a clinical method of visual observation to evaluate uninjured professional baseball players for the presence of scapular dyskinesis using a scapular classification system recommended in the literature [6][7][8]19]. The presence of subtle scapular dyskinesis identified in laboratory studies [13,15] in overhead athletes coupled with the reported consequences of scapular dyskinesis on high-level overhead upper extremity function [6,7,9] highlight the importance of early identification and recognition of scapular pathology in overhead athletes to both prevent injury and optimize performance. The overall purpose of this study was to use a clinical method of visual observation to evaluate the scapula of uninjured professional baseball players to determine the interrater reliability of visual observation and the Kibler et al [8] scapular classification system.…”

“…Several studies have identified alterations in scapular movement in healthy uninjured overhead athletes [10,13,15]. Myers et al [13] measured increased scapular upward rotation, internal rotation, and retraction in throwing athletes on their dominant throwing extremity as compared with a control group of nonthrowers.…”

“…This decrease in upward rotation may compromise the acromiohumeral interval during overhead motion and increase injury risk in individuals in this population. Finally, Oyama et al [15] measured scapular posture in a population of 43 overhead athletes. They found greater scapular protraction in tennis players on the dominant shoulder than on the nondominant side.…”

“…Additionally, overhead athletes often present with subtle scapular dysfunction, not gross disassociation of the scapula away from the thorax as is seen in patients with nerve injury and other conditions [6,7,19]. Use of a classification system to evaluate subtle scapular dysfunction has been advocated and requires study on this population of overhead athletes who present with subtle scapular movement deviations in laboratory studies [5,9,10,13,15].…”

Confiabilidade da avaliação da orientação e posição de repouso da escápula de indivíduos saudáveis e sedentários com o sistema eletromagnético de aquisição de dados

“…Assessment of scapular positioning is a theme has been emphasized in scientific literature [1][2][3][4][5][6][7][8][9][10][11] . Positioning and orientation of the scapula on thorax are important to centralize the humeral head and base for normal function of shoulder joint complex during daily and sport activities [5][6][7]9 .…”