Background and Purpose. Treatment of patients with impingement symptoms commonly includes exercises intended to restore "normal" movement patterns. Evidence that indicates the existence of abnormal patterns in people with shoulder pain is limited. The purpose of this investigation was to analyze glenohumeral and scapulothoracic kinematics and associated scapulothoracic muscle activity in a group of subjects with symptoms of shoulder impingement relative to a group of subjects without symptoms of shoulder impingement matched for occupational exposure to overhead work. Subjects. Fifty-two subjects were recruited from a population of construction workers with routine exposure to overhead work. Methods. Surface electromyographic data were collected from the upper and lower parts of the trapezius muscle and from the serratus anterior muscle. Electromagnetic sensors simultaneously tracked 3-dimensional motion of the trunk, scapula, and humerus during humeral elevation in the scapular plane in 3 handheld load conditions: (1) no load, (2) 2.3-kg load, and (3) 4.6-kg load. An analysis of variance model was used to test for group and load effects for 3 phases of motion (31°-60°, 61°-90°, and 91°-120°). Results. Relative to the group without impingement, the group with impingement showed decreased scapular upward rotation at the end of the first of the 3 phases of interest, increased anterior tipping at the end of the third phase of interest, and increased scapular medial rotation under the load conditions. At the same time, upper and lower trapezius muscle electromyographic activity increased in the group with impingement as compared with the group without impingement in the final 2 phases, although the upper trapezius muscle changes were apparent only during the 4.6-kg load condition. The serratus anterior muscle demonstrated decreased activity in the group with impingement across all loads and phases. Conclusion and Discussion. Scapular tipping (rotation about a medial to lateral axis) and serratus anterior muscle function are important to consider in the rehabilitation of patients with symptoms of shoulder impingement related to occupational exposure to overhead work. [Ludewig PM, Cook TM. Alterations in shoulder kinematics and associated muscle activity in people with symptoms of shoulder impingement. Phys Ther. 2000;80:276 -291.]

No abstract

The second international consensus conference on the scapula was held in Lexington Kentucky. The purpose of the conference was to update, present and discuss the accumulated knowledge regarding scapular involvement in various shoulder injuries and highlight the clinical implications for the evaluation and treatment of shoulder injuries. The areas covered included the scapula and shoulder injury, the scapula and sports participation, clinical evaluation and interventions and known outcomes. Major conclusions were (1) scapular dyskinesis is present in a high percentage of most shoulder injuries; (2) the exact role of the dyskinesis in creating or exacerbating shoulder dysfunction is not clearly defined; (3) shoulder impingement symptoms are particularly affected by scapular dyskinesis; (4) scapular dyskinesis is most aptly viewed as a potential impairment to shoulder function; (5) treatment strategies for shoulder injury can be more effectively implemented by evaluation of the dyskinesis; (6) a reliable observational clinical evaluation method for dyskinesis is available and (7) rehabilitation programmes to restore scapular position and motion can be effective within a more comprehensive shoulder rehabilitation programme.

Overall shoulder motion consists of substantial angular rotations at each of the four shoulder joints, enabling the multiple-joint interaction required to elevate the arm overhead.

Clinical selection of exercises for improving scapular control should consider both maximum serratus activation and upper trapezius/serratus anterior ratios.

Study Design: Two-group comparison. Objective: To compare scapular kinematics during arm elevation between groups distinguished by pectoralis minor resting length. Background: Studies have demonstrated that individuals with subacromial impingement have altered scapular kinematics, such as loss of posterior tipping and increased internal rotation. One proposed mechanism for these alterations is an adaptively short pectoralis minor. This anterior scapulothoracic muscle may impact normal scapular kinematics if adaptively short. Methods and Measures: Fifty volunteers without shoulder pain were divided into long or short groups according to normalized pectoralis minor resting length. An electromagnetic motion capture system determined the angular orientation of the scapula, humerus, and trunk during arm elevation in 3 separate planes. Groups were compared for 3-dimensional scapular orientation relative to the trunk at arm elevation angles of 30°, 60°, 90°, and 120°, using a mixed-model analysis of variance (ANOVA). Results: There were statistically significant interaction effects between group and arm elevation angle for scapular tipping in all planes of arm elevation, with the scapula for the short group staying anteriorly tipped at higher angles. There was also a significant interaction for scapular internal rotation at lower arm elevation angles in the coronal plane only, with individuals with a shorter pectoralis minor demonstrating a more internally rotated scapula. Conclusions:The group distinguished by a short pectoralis minor demonstrated scapular kinematics similar to the kinematics exhibited in earlier studies by subjects with shoulder impingement. These results support the theory that an adaptively short pectoralis minor may influence scapular kinematics and is therefore a potential mechanism for subacromial impingement. J Orthop Sports Phys Ther 2005;35:227-238.

Background: Repetitive or sustained elevated shoulder postures have been identified as a significant risk factor for occupationally related shoulder musculoskeletal disorders. Construction workers exposed to routine overhead work have high rates of shoulder pain that frequently progresses to functional loss and disability. Exercise interventions have potential for slowing this progression. Aims: To evaluate a therapeutic exercise programme intended to reduce pain and improve shoulder function. Methods: Construction worker volunteers were screened by history and clinical examination to test for inclusion/exclusion criteria consistent with shoulder pain and impingement syndrome. Sixty seven male symptomatic workers (mean age 49) were randomised into a treatment intervention group (n = 34) and a control group (n = 33); asymptomatic subjects (n = 25) participated as an additional control group. Subjects in the intervention group were instructed in a standardised eight week home exercise programme of five shoulder stretching and strengthening exercises. Subjects in the control groups received no intervention. Subjects returned after 8-12 weeks for follow up testing. Results: The intervention group showed significantly greater improvements in the Shoulder Rating Questionnaire (SRQ) score and shoulder satisfaction score than the control groups. Average post-test SRQ scores for the exercise group remained below levels for asymptomatic workers. Intervention subjects also reported significantly greater reductions in pain and disability than controls. Conclusions: Results suggest a home exercise programme can be effective in reducing symptoms and improving function in construction workers with shoulder pain.

levation of the arm for overhead activities is accomplished by combined motion at multiple articulations of the shoulder, including the sternoclavicular, acromioclavicular, and glenohumeral joints (24,48). Some authors include the scapulothoracic articulation when describing shoulder anatomy and kinesiology (24,29). Due to the ligamentous and capsular attachments of the scapula to the clavicle and the clavicle to the sternum, scapulothoracic movement requires motion of the clavicle on the thorax at the sternoclavicular joint, motion of the scapula relative to the clavicle at the acromioclavicular joint, o r some combination of both (24). Scapulothoracic motion, therefore, is a summation of sternoclavicular and acromioclavicular motion, and, subsequently, elevation of the arm is frequently described in terms of scapulothoracic and glenohumeral components.Cathcart, while observing arm movements in living subjects, first suggested that glenohumeral and scapulothoracic motion occur synchronously when lifting the arm overhead (7). Codman later termed this synchronous motion, scapulohumeral rhythm (8). Since that time, a great deal of research in shoulder kinematics has been directed toward the study of scapulohumeral rhythm (2, 14,19,24,45,48)