Lesson
Shoulder/Glenohumeral Joint
NOTES:
1.Head of humerus forms the ‘ball’ and glenoid fossa the ‘socket’
2.Freedom of movement has developed at the expense of stability
3.Glenoid fossa faces laterally, anteriorly and slightly superiorly; the humerus, faces superiorly, medially and posteriorly
4.The plane of the glenoid fossa lies 45º to both the frontal and sagittal planes, and TRUE flexion/extension take place perpendicular to THIS plane, with abduction/adduction about an axis parallel to the plane of the glenoid fossa. All 4 of these motions are accompanied by scapular and clvicular movement
5.Medial and lateral rotation take place about a longitudinal axis through the humerus. In lateral rotation (ROM 80º), the anterior surface of the humerus is turned laterally. In medial rotation (ROM >90º), anterior humerus turns medially. To assess ROM of shoulder rotation, the elbow must be flexed to exclude the effect of any forearm pronation/supination