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Abstract Background Function loss caused by rotator cuff tears alters the scapular orientation, however, few prior studies have reported on scapular movements after rotator cuff repair. The purpose was to determine the scapular orientations before and after rotator cuff repair. Methods We recruited 14 healthy controls, 10 small and six massive rotator cuff tear in patients. The scapular upward rotation during arm elevation was analyzed using fluoroscopic imaging. Findings Before surgery, both rotator cuff groups demonstrated greater scapular upward rotation compared to healthy controls. Two months postoperation, the analyses showed significant differences between the patients with small rotator cuff tears and healthy controls at arm elevations of 90°, and between patients with both rotator cuff tear groups and healthy controls at arm elevations of 120°. At five months post-operation, significant differences still existed between the healthy controls and both rotator cuff groups. In regard to the temporal effects in the patients with small rotator cuff tears, the scapular upward rotation decreased significantly over time (2–5 months postoperation) at arm elevations of 120°. We did not identify a main effect owing to time in the patients with massive rotator cuff tears. Interpretation In patients with small rotator cuff tears, scapular upward rotation was reduced over the period of 2–5 months postoperation, however, the patients with massive rotator cuff tears showed greater scapular upward rotation throughout the experimental period. The results suggested that the execution of the rehabilitation program should consider that the tear size could affect scapular motion. Highlights • The scapular upward rotation during arm elevation was analyzed. • Rotator cuff tears patients participated at preop, two and five months postop. • The patients with small tears showed greater movement at two months postop. • However, this movement decreased over the period of 2–5 months postop. • The massive tears led to greater motion throughout the experimental period. [ABSTRACT FROM AUTHOR]

Background Altered scapular kinematics have been associated with shoulder pain and functional limitations. To understand kinematics in persons with spinal cord injury during manual handrim wheelchair propulsion, a description of normal scapular behaviour in able-bodied persons during this specific task is a prerequisite for accurate interpretation. The primary aim of this study is to describe scapular kinematics in able-bodied persons during manual wheelchair propulsion. Methods Sixteen able-bodied, novice wheelchair users without shoulder complaints participated in the study. Kinematic and kinetic data were collected during a standardized pose in the anatomic posture, frontal-plane arm elevation and low-intensity steady-state handrim wheelchair propulsion and upper-body Euler angles were calculated. Findings Scapulothoracic joint orientations in a static position were 36.7° (SD 5.4°), 6.4° (SD 9.1°) and 9.1° (SD 5.7°) for respectively protraction, lateral rotation and anterior tilt. At 80° of arm elevation in the frontal plane, the respective values of 33.4° (SD 8.0°), 23.9° (SD 5.4°) and 4.1° (SD 11.3°) were found. During the push phase of manual wheelchair propulsion, the mean scapular rotations were respectively 32.7° (SD 7.1°), 7.1° (SD 9.2°) and 9.8° (SD 8.3°). Interpretation The orientation of the scapula in a static pose, during arm elevation and in manual wheelchair propulsion in able-bodied participants showed similar patterns to a previous study in persons with para- and tetraplegia. These values provide a reference for the investigation of the scapular movement pattern in wheelchair-dependent persons and its relation to shoulder complex abnormalities. [ABSTRACT FROM AUTHOR]

Background Scapular motion is closely integrated with arm motion. Injury to a distal segment requires compensatory changes in the proximal segments leading to alterations in scapular motion. Since the effects of distal injuries on scapular kinematics remain unknown, in the present study we investigated the influences on scapular motion in patients with distal injuries. Methods Sixteen subjects with a history of distal radius fracture and 20 asymptomatic healthy subjects (controls) participated in the study. Three-dimensional scapular and humeral kinematic data were collected on all 3 planes of shoulder elevation: frontal, sagittal, and scapular. All testing was performed in a single session; therefore, the sensors remained attached to the participants for all testing. The position and orientation data of the scapula at 30°, 60°, 90°, and 120° humerothoracic elevation and 120°, 90°, 60°, and 30° lowering were used for statistical comparisons. Independent samples t -test was used to compare the scapular internal/external rotation, upward/downward rotation, and anterior/posterior tilt between the affected side of subjects with a distal radius fracture and the dominant side of asymptomatic subjects at the same stage of humerothoracic elevation. Findings Scapular internal rotation was significantly increased at 30° elevation ( P = 0.01), 90° elevation ( P = 0.03), and 30° lowering ( P = 0.03), and upward rotation was increased at 30° and 60° elevation ( P < 0.001) on the affected side during frontal plane elevation. Scapular upward rotation and anterior tilt were significantly increased during 30° lowering on both the scapular (P = 0.002 and 0.02, respectively) and sagittal planes ( P = 0.01 and 0.02. respectively). Interpretation Patients with distal radius fractures exhibit altered scapular kinematics, which may further contribute to the development of secondary musculoskeletal pathologies. [ABSTRACT FROM AUTHOR]

Abstract: Background: Dental hygienists suffer a high incidence of shoulder pathology that seems to increase with job longevity. It has been hypothesized that occupational injuries could be due to local muscle fatigue caused by repetitive low level work and awkward and constrained working postures. In the laboratory, scapular kinematics can be temporarily altered using fatiguing protocols. It is unknown whether or not workday fatigue causes changes to scapular kinematics. The aim of this study was to examine if changes in scapular tilt and rotation occurs after a workday in dental hygienists. Methods: The pre and post workday scapular kinematics were recorded from dental hygienists using an electromagnetic tracking system. All data were recorded within the place of employment of the dental hygienist. Results: Following the workday, there was significantly more scapular anterior tilt in dental hygienists (P <0.05); however, no changes were found for upward or internal rotation. Greater kinematic differences were found for hygienists with greater job longevity. Interpretation: The increase in scapular anterior tilting could be due to post workday fatigue. Anterior tilting of the scapula may have an influence on the development of subacromial impingement syndrome. Hygienists with greater duration of work experience may be at greater risk for developing shoulder injuries as they have more anterior tilting of the scapula post workday. [Copyright &y& Elsevier]

Abstract: Background. Patients with full thickness rotator cuff tears typically demonstrate an increase in scapular motion, both in the clinic and under controlled laboratory conditions. To better understand the mechanisms behind this pattern of motion, we propose a suprascapular nerve block as an appropriate model of dysfunction of the supraspinatus and infraspinatus, which are the two tendons most commonly affected in cuff tear patients. Methods. Healthy subjects underwent testing for 3D scapular kinematics with a Polhemus magnetic tracking device and isometric force measurements during external rotation. A suprascapular nerve block was then performed with the injection of lidocaine into the suprascapular notch of each subject. Scapular kinematics and isometric force measurements were repeated after confirmation of the block. Findings. The nerve block resulted in no significant changes in clavicular rotations and scapular posterior tilting. However, there was a significant increase in scapular external rotation and upward rotation. While kinematic changes returned to baseline within 25min of the block, force measurements did not return to baseline until 75min post-block. Interpretation. The results of this study, especially those for upward rotation, are in general agreement with what has been found for patients with rotator cuff tears. While the supraspinatus and infraspinatus do not directly control the movement of the scapula, they appear to result in a compensatory change in scapular motion. Although more work needs to be done, it appears that abnormal scapular motion patterns observed in patients with cuff tears may therefore be compensatory in nature. [Copyright &y& Elsevier]

This study used in vivo three-dimensional to two-dimensional image registration techniques to compare the glenohumeral kinematics of shoulders with massive rotator cuff tears that were successfully treated conservatively and those of normal shoulders. Ten patients (age, 67.4 ± 3.63 years) with massive rotator cuff tears on one side and without contralateral tears were enrolled. We performed computed tomography and fluoroscopy on both shoulder joints and created three-dimensional bone models of the humerus and scapula using image registration techniques. We measured the humeral superoinferior translation, angle of humeral external rotation, scapular upward rotation, scapular anteroposterior tilt, and scapular external rotation of the torn shoulders with good range of motion after effective conservative treatment and compared these measurements to those of the contralateral normal shoulders. There was a significant difference in the initial position of the humeral head relative to the glenoid in the tear group; it was 2.0 mm higher than that in the normal group (p <.05). This difference disappeared in the range from 40° to full elevation. The scapular motion of the tear group was significantly more upwardly rotated than that of the normal group: by 9.9° at rest (p <.05) and by 11.6° at terminal elevation (p <.05). No significant differences were detected for humeral head external rotation, scapular anteroposterior tilt, and scapular external rotation between the two groups. Kinematics of shoulders with massive cuff tears could not be recovered completely even though the patients had no significant symptoms after successful conservative treatment. • Humeral head in the massive rotator cuff tear more superiorly located in the initial position. • Scapula rotated further upward at rest and terminal elevation in the massive cuff tear • No significant difference in superoinferior translation and upward rotation in midrange • Kinematics of massive cuff tear cannot recover entirely despite of conservative treatment. [ABSTRACT FROM AUTHOR]