Alterations in Scapular Kinematics in Subjects With Idiopathic Loss of Shoulder Range of Motion

Abstract

Etiologic investigations have focused primarily on the glenohumeral joint. Proposed etiologies include decreased capsular volume, 20,33 degenerative changes, 2,47 shoulder capsule adhesions, 1,30,31 synovitis, 14,46,47 and thickened synovium. 11,24These etiologic investigations have led to multiple alternative labels proposed in the literature. The most frequently cited are adhesive capsulitis and frozen shoulder. These labels are essentially interchangeable with idiopathic loss of shoulder ROM. Subjects with idiopathic loss of shoulder ROM consistently report decreased motion in multiple planes. 7,15,41 Frequent functional complaints include difficulty getting dressed, completing personal hygiene, 29 and performing tasks requiring overhead reaching. 15 Performance of these activities of daily living requires the combined and coordinated motions of the scapulothoracic and glenohumeral joints.The scapula links the humerus to the trunk. Scapulothoracic motion is necessary to achieve full humerus-to-trunk scapular plane elevation. Cathcart 6 was the first to recognize the scapulothoracic contribution to normal shoulder complex kinematics. He determined that the scapula moved on the thorax throughout humerus elevation. Many terms have been utilized to describe the movement of the scapula on the thorax. For consistency, this article will use terminology presented by Ludewig et al. 22 Upward/downward rotation occurs around an axis perpendicular to the plane of the scapula. Posterior/anterior tipping occurs around an axis approximately parallel to the spine of the scapula. Internal/external rotation occurs around a vertical axis.Scapular motion on the thorax dur-PETER J. RUNDQUIST, PT, PhD The condition affects 3% of the population. 32 Despite several authors' reports that the condition spontaneously resolves within 2 years, 7,13 subjects continue to report shoulder pain, stiffness, or both for up to 7 years. MATERIALS AND METHODS:Seventeen unilaterally impaired and 17 nonimpaired subjects. The 3-dimensional motion of the humerus, scapula, and trunk were measured with the Fastrak electromagnetic motion-tracking system during humerus-to-trunk scapular plane elevation. An analysis of variance compared the impaired subjects noninvolved to the nonimpaired subjects' scapulae at 4 scapular plane elevation positions. A repeated-measures analysis of variance compared the impaired subjects' involved and noninvolved scapulae at 3 scapular plane elevation positions, and matched-pairs t test compared peak elevation values. RESULTS:The between-group ANOVAs demonstrated no difference in anterior tipping, internal rotation, or upward rotation. The repeated-measures ANOVAs demonstrated no difference in anterior tipping or internal rotation and a position-by-side interaction in upward rotation. The involved-side scapulae were more upwardly rotated (7.7°) at peak humerus-to-trunk scapular plane elevation. DISCUSSION AND CONCLUSION:The impaired subjects' noninvolved scapular kinematics were not significantly different than the nonimpair...

Scapulothoracic motion and muscle activity during the raising and lowering phases of an overhead reaching task

“…It should be noted that the average pattern of motion for scapular external/internal rotation and scapular tilting differed between our study and that of Borstad and Ludewig (2002). Different patterns of scapular external/internal rotation and scapular tilting have previously been reported and may be a reflection of differences in subject characteristics such as presence or absence of shoulder pain and gender (Ebaugh et al, 2005;McClure et al, 2001;Rundquist, 2007). Although the differences for scapular external rotation, clavicular elevation and clavicular retraction between the raising and lowering phases of motion were greater than our measurement error, these differences were small.…”

Analysis of the scapulohumeral rhythm and electromyography of the shoulder muscles during elevation and lowering: Comparison of dominant and nondominant shoulders

“…24 An increased scapular component is generally thought to contribute to the SHR in frozen or stiff shoulder. 32,33,39 Thus, shoulder disorders manifest as abnormal motion of the STor GH joint and consequently alter the SHR. Comparison of the SHR between both shoulders would be clinically beneficial to evaluate shoulder disorders.…”

“…21,24,27,28,32,33,39,41 Alterations in the resting scapular position and dynamic scapular motion occur frequently in association with many types of shoulder disorders, including impingement, instability, rotator cuff tears, and frozen shoulder. 21 Scapular upward rotation is significantly increased in patients with full-thickness rotator cuff tears compared with controls in both forward and scapular plane elevation, 28 and the supraspinatus and serratus anterior muscles exhibit significantly less activity during abduction and forward elevation with anterior instability compared with normal shoulders.…”

Validity and Reliability of an Instrument to Assess the Posterior Scapular Displacement

“…Once asymmetry was identified, the evaluators were asked to classify the dyskinesis in one of these four types, based on the predominant pattern [16]. In a second step, all individuals classified with scapular dyskinesis (type I, II or III) were grouped into a single category: "with posterior scapular displacement" and subjects classified as type IV were included in the category "without posterior scapular displacement".…”