Proper scapular motion is crucial for normal shoulder mechanics. Scapular motion affects glenohumeral joint function during throwing, yet little is known about this dynamic activity. Asymptomatic subjects (10 male and 10 female), ages 21 to 45, were analyzed. Electromagnetic surface sensors on the sternum, acromion, and humerus were used to collect 3-D motion data during three trials of low-vel...

BACKGROUND Contractile tissue plays an important role in mobility deficits in frozen shoulder (FS). However, no study has assessed the effect of the muscle release technique on the muscle activation and kinematics in individuals with FS. The purposes of this study were to assess the differences in shoulder muscle activity and kinematics between the FS and asymptomatic groups; and to determine t...

The purpose of this manuscript is to review the knowledge of scapular positioning at rest and scapular movement in different anatomic planes in asymptomatic subjects and patients with shoulder impingement syndrome (SIS) and glenohumeral shoulder instability. We reviewed the literature for all biomechanical and kinematic studies using keywords for impingement syndrome, shoulder instability, and ...

Background: Altered scapular kinematics in individuals with rounded shoulder posture (RSP) may affect acromiohumeral distance (AHD). The purpose of this study was to compare AHD and scapular dyskinesis prevalence in individuals with and without RSP.    Methods: A total of 44 women (RSP, n=21; control, n=23) participated in the study. RSP was assessed by measuring acromion to table distance (AT...

While fatigue of the rotator cuff demonstrably causes superior humeral head migration and concomitant risk of impingement, the relationship between specific muscular fatigue, scapular dyskinesis and impingement risk is less clear. The purpose of this study was to examine changes in scapular orientation following a simulated prone rowing fatiguing protocol that targeted the scapula stabilizing m...

The aim of this study was to establish the optimal methodology for skin-fixed measurement of the scapula during dynamic movement. This was achieved by comparing an optimally positioned Scapula Tracker device (ST) to a previously described palpation device, taken as the true measure of scapular kinematics. These measurements were compared across a range of calibration positions, including the us...

The present study aimed to compare the shoulder kinematics (3D scapular orientation, scapular angular displacement and scapulohumeral rhythm) of asymptomatic participants under unloaded and loaded conditions during unilateral shoulder elevation in the scapular plane. We utilized a repeated measures design with a convenience sample. Eleven male participants with an age range of 21 to 28 years wi...

Objective: To describe to what degree and in what plane biomechanical alterations occur during the performance of the Scapular Retraction test (SRT) and Scapular Assistance Test (SAT). Design: Laboratory Pilot Study Participants: Eight symptomatic and 7 asymptomatic subjects were instrumented with electromagnetic sensors. Main Outcome Measures: The SRT and SAT were performed with the scapula st...

The measurement of humeral kinematics with a sensor on the humerus is susceptible to large errors due to skin motion artifacts. An alternative approach is to use data from a forearm sensor, combined with data from either a scapular or thoracic sensor. We used three tasks to assess the errors of these approaches: humeral elevation, elbow flexion and humeral internal rotation. Compared with the h...