Shoulder Function and 3-Dimensional Scapular Kinematics in People With and Without Shoulder Impingement Syndrome

Abstract

Background and Purpose. Several factors such as posture, muscle force, range of motion, and scapular dysfunction are commonly believed to contribute to shoulder impingement. The purpose of this study was to compare 3-dimensional scapular kinematics, shoulder range of motion, shoulder muscle force, and posture in subjects with and without primary shoulder impingement syndrome. Subjects. Forty-five subjects with impingement syndrome were recruited and compared with 45 subjects without known pathology or impairments matched by age, sex, and hand dominance. Methods. Shoulder motion and thoracic spine posture were measured goniometrically, and force was measured with a dynamometer. An electromagnetic motion analysis system was used to capture shoulder kinematics during active elevation in both the sagittal and scapular planes as well as during external rotation with the arm at 90 degrees of elevation in the frontal plane. Results. The impingement group demonstrated slightly greater scapular upward rotation and clavicular elevation during flexion and slightly greater scapular posterior tilt and clavicular retraction during scapular-plane elevation compared with the control group. The impingement group demonstrated less range of motion and force in all directions compared with the control group. There were no differences in resting posture between the groups. Discussion and Conclusion. The kinematic differences found in subjects with impingement may represent scapulothoracic compensatory strategies for glenohumeral weakness or motion loss. The decreased range of motion and force found in subjects with impingement support rehabilitation approaches that focus on strengthening and restoring flexibility.

Differences in Scapular Orientation Between Standing and Sitting Postures at Rest and in 120° Scaption: A Cross‐Sectional Study

“…If thoracic or lumbar position is addressed initially, then body posture is not relevant; however, because the monitoring of specific thoracic or lumbar position may be difficult for patients during functional tasks, home exercise, or postural programs, then the simple use of body posture may be more achievable for some patients. Given that shoulder pain is associated with either scapular upward or downward rotation [4,11,12,14,20,22,24,25], anterior or posterior tilt [4,5,8,9,[11][12][13][14]16], and medial or lateral translation [9,20,22], then individual patient presentations will guide the selection of body posture. Slouched sitting posture also can decrease glenohumeral range of motion in comparison to neutral sitting in participants with shoulder pain [27,55].…”

“…Scapular orientation is considered a primary influence in the development and maintenance of shoulder pain [1,2]. Although it is acknowledged that shoulder pain may be multifactorial, a majority of cross-sectional studies demonstrate a significant difference between symptomatic and asymptomatic groups [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] for scapular orientation in diverse conditions such as spinal cord injury [18], after breast cancer treatment [16], chronic obstructive pulmonary disease [19], rotator cuff tendinopathies [13,15], glenohumeral or acromioclavicular osteoarthritis [13,20], adhesive capsulitis [13], internal impingement [14], and multidirectional instability [12]. In addition, a number of longitudinal studies have demonstrated that scapular orientation or dyskinesis assessed under load can be predictive of shoulder pain [21][22][23].…”

“…Although the association between scapular orientation and shoulder pain is clear, maladaptive scapular orientation may be multidirectional, with a recent systematic review reporting opposing that scapular orientations are linked to shoulder pain in shoulder impingement syndrome [1]. Both increased and decreased scapular upward rotation [4,11,12,14,20,22,24,25], posterior tilt [4,5,8,9,[11][12][13][14]16], medial rotation [4,6,7,12,13,16], and lateral translation [9,20,22] have been associated with shoulder pain. Elevation appears to be the only scapular orientation that has a unidirectional (increased) association with shoulder pain [8,9,11,14,15].…”

Comparing the Isometric Strength of the Shoulder and Scapulothoracic Muscles in Volleyball and Futsal Athletes

“…Muscle weakness and muscle imbalance can cause impingement of the shoulder joint syndrome, therefore, evaluation of the ratio of antagonist-agonist of the scapulothoracic muscle on one side can help diagnose and treat [2,8,[22][23][24]. To measure the elevation to depression ratio of the scapula, the upper trapezius muscle was considered for elevation and the lower trapezius for depression [15].…”

Scapular Orientation During Planar and Three-dimensional Upper Limb Movements in Individuals with Anterior Glenohumeral Joint Instability

“…Joint stability, defined as the ability of a joint to resist dislocation, is essential for proper joint function (Hall 2003). Proper scapular kinematics (upward rotation, posterior tipping and lateral rotation) during upper limb elevation is important in maintaining GHJ stability (Itoi et al, 1992;Matias and Pascoal, 2006;Struyf et al, 2011) as well as preventing injuries (Brewer et al, 1986;Ludewig and Cook, 2000;Graichen et al, 2001;McClure et al, 2006). After an anterior GHJ dislocation, injured passive joint stabilizers may not be able to provide sufficient mechanical stabilization to maintain the humeral head within the glenoid cavity (Turkel et al, 1981;Itoi et al, 1996;Brenneke et al, 2000;von Eisenhart-Rothe et al, 2002).…”