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Concept: Acromion

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Synopsis Stretching techniques that focus on increasing posterior shoulder soft tissue flexibility are commonly incorporated into prevention and treatment programs for the overhead athlete. The cross body and sleeper stretch exercises have been described as stretching techniques to improve posterior shoulder soft tissue flexibility and increase glenohumeral internal rotation and horizontal adduction range of motion in the overhead athlete. But based on the inability to stabilize the scapula and control glenohumeral rotation with the cross body stretch and the potential for subacromial impingement with the sleeper stretch, the authors recommend modifications to both of these commonly performed stretches. This clinical commentary reviews the literature on posterior shoulder stretches, describes modifications to both of these commonly performed stretches, and outlines a strategy to maintain or improve posterior shoulder soft tissue flexibility and glenohumeral internal rotation range of motion in the overhead athlete. Level of Evidence Therapy, level 5. J Orthop Sports Phys Ther, Epub 30 October 2013. doi:10.2519/jospt.2013.4990.

Concepts: Physical exercise, Exercise, Tissues, Classical mechanics, Shoulder, Range of motion, Stretching, Acromion

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To compare the accuracy and efficacy of ultrasound (US)-guided injections versus landmark-guided injections of the subacromial space, biceps tendon sheath, acromioclavicular (AC) joint and glenohumeral (GH) joint.

Concepts: Skeletal system, Joints, Clavicle, Glenohumeral joint, Qualities of thought, Acromion

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Study Design Cross-sectional. Objectives To compare differences in glenohumeral joint angular motion and linear translations between symptomatic and asymptomatic individuals during shoulder motion performed in 3 planes of humerothoracic elevation. Background Numerous clinical theories have linked abnormal glenohumeral kinematics including decreased glenohumeral external rotation and increased superior translation to individuals with shoulder pain and impingement diagnoses. However, relatively few studies have investigated glenohumeral joint angular motion and linear translations in this population. Methods Transcortical bone pins were inserted into the scapula and humerus of 12 asymptomatic and 10 symptomatic participants for direct bone-fixed tracking using electromagnetic sensors. Glenohumeral joint angular positions and linear translations were calculated during active shoulder flexion, abduction, and scapular plane abduction. Results Differences between groups in angular positions were limited to glenohumeral elevation coinciding with a reduction in scapulothoracic upward rotation. Symptomatic participants demonstrated 1.4 mm more anterior glenohumeral translation between 90 and 120° shoulder flexion and an average of 1 mm more inferior glenohumeral translation throughout shoulder abduction. Conclusion Differences in glenohumeral kinematics exist between symptomatic and asymptomatic individuals. The clinical implications of these differences are not yet understood and more research is needed to understand the relationship between abnormal kinematics, shoulder pain, and pathoanatomy. J Orthop Sports Phys Ther, Epub 7 August 2014. doi:10.2519/jospt.2014.5556.

Concepts: Biceps brachii muscle, Classical mechanics, Shoulder, Rotator cuff, Deltoid muscle, Coracoid process, Glenohumeral joint, Acromion

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Study Design Cross-sectional. Objectives To compare sternoclavicular, acromioclavicular, and scapulothoracic joint motion between symptomatic and asymptomatic individuals during shoulder motion performed in 3 planes of humerothoracic elevation. Background Differences in scapulothoracic kinematics are associated with shoulder pain. Several studies have measured these differences using surface sensors but the results may be affected by skin motion artifact. Furthermore, previous studies have not included the simultaneous measurement of sternoclavicular and acromioclavicular joint motion. Methods Transcortical bone pins were inserted into the clavicle, scapula, and humerus of 12 asymptomatic and 10 symptomatic individuals for direct bone-fixed tracking using electromagnetic sensors. Angular positions for the sternoclavicular, acromioclavicular, and scapulothoracic joints were measured during shoulder flexion, abduction, and scapular plane abduction. Results Differences between groups were found for sternoclavicular and scapulothoracic joint position. Symptomatic individuals consistently demonstrated less sternoclavicular posterior rotation regardless of angle, phase, or plane of shoulder motion. Symptomatic individuals also demonstrated less scapulothoracic upward rotation at 30 and 60° of humerothoracic elevation during shoulder abduction and scapular plane abduction. Conclusion Differences in shoulder complex kinematics exist between symptomatic and asymptomatic individuals. However, the magnitudes of differences were small and the resulting clinical implications are not yet fully understood. The biomechanical coupling of the sternoclavicular and acromioclavicular joints requires further research to better understand scapulothoracic movement deviations and improve manual therapy and exercise-based physical therapy interventions. J Orthop Sports Phys Ther, Epub 7 August 2014. doi:10.2519/jospt.2014.5339.

Concepts: Knee, Physical therapy, Synovial joint, Joints, Shoulder, Deltoid muscle, Clavicle, Acromion

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Injuries to the acromioclavicular joint and coracoclavicular ligaments are common. Many of these injuries heal with nonoperative management. However, more severe injuries may lead to continued pain and shoulder dysfunction. In these patients, surgical techniques have been described to reconstruct the function of the coracoclavicular ligaments to provide stable relationship between the clavicle and scapula. These surgeries have been fraught with high complication rates including clavicle and coracoid fractures, infection, loss of reduction and fixation, hardware migration, and osteolysis. This article reviews common acromioclavicular and coracoclavicular repair and reconstruction techniques and associated complications, and provides recommendations for prevention and management.

Concepts: Bone, Joint, Shoulder, Clavicle, Coracoid process, Coracoclavicular ligament, Scapula, Acromion

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There is evidence that pectoralis minor (PM) length influences scapula position and that scapula position relates to glenohumeral joint (GHJ) external rotation (ER) range of motion (ROM).

Concepts: Shoulder, Coracoid process, Glenohumeral joint, Acromion

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Clavicle fracture is known to be one of the injuries frequently occurring in the elderly. The purpose of this study was to characterise the internal structures that might correlate with the higher incidence of lateral clavicle fracture in the elderly. Twenty clavicles were collected from ten Japanese cadavers ranging from 70 to 99 years (83.6 ± 7.6), scanned, and three-dimensional computed tomography (3D CT) images reconstructed. The clavicle lengths were divided into five equal segments. The four demarcation lines from the acromial end of the clavicle were defined as the observation points A, B, C, and D. The clavicles were then measured and analysed. It was shown that along the clavicles observation point A was the widest and points B and C the narrowest. Regarding the thickness, point D was the thickest among all four points, and there was no significant difference among the points A, B, and C. No male-female difference was found in either the cortical or cancellous bone ratio at all four points. Interestingly, the highest cortical bone ratio was observed at point B and the ratio was significantly decreased toward either end. The cancellous bone ratio was highest at point C and decreased toward both ends. Further observations showed that there were rays of trabeculae around point A, spreading from the superior-posterior edge or anterior edge toward each other and toward the lateral end and point B. Characteristics in the cortical and cancellous bone ratios and cancellous bone patterns might shed light on understanding the fractures in the lateral portion of the clavicle in the elderly.

Concepts: Scientific method, Bone, Skeletal system, Osseous tissue, Cortical bone, Clavicle fracture, Clavicle, Acromion

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