The roentgenographic parameters of motion in normal and abnormal shoulders, including the movement of the scapula, arm angle, glenohumeral angle, scapulothoracic angle, excursion of the humeral head, and instant center of motion for abduction in the plane of the scapula, were determined in twelve normal subjects and fifteen patients. The scapula rotated externally with abduction. The ratio of g...

BACKGROUND The effect of osteoallograft repair of a Hill-Sachs lesion and the effect of allograft fit on glenohumeral translations in response to applied force are poorly understood. PURPOSE To compare the impact of a 25% Hill-Sachs lesion, a perfect osteoallograft repair (PAR) of a 25% Hill-Sachs lesion, and an "imperfect" osteoallograft repair (IAR) of a 25% Hill-Sachs lesion on glenohumera...

[Purpose] The aim of this study was to analyze the joint space width of the humeral head and glenoid fossa during traction under 2 grade conditions (grade 2/grade 3). [Subjects and Methods] The subjects were 20 healthy male adults who had not experienced any shoulder injury. Three radiographs were obtained with the subjects in the supine position (resting, grades 2 and 3). The glenohumeral join...

We examined the architectural properties of the rotator cuff muscles in 10 cadaveric specimens to understand their functional design. Based on our data and previously published joint angle-muscle excursion data, sarcomere length operating ranges were modeled through all permutations in 75 masculine medial and lateral rotation and 75 masculine abduction at the glenohumeral joint. Based on physio...

ONE OF THE PRIMARY RESPONsibilities of the personal trainer or strength and conditioning specialist is educating clients in proper exercise techniques. More importantly, however, the strength and conditioning professional must be able to design exercise programs that are appropriate and safe for each client. Because there is a wide range of exercises to choose from when targeting specific muscl...

Fractures of the proximal humerus may involve either the true articular surface of the glenohumeral joint, the gliding surface of the subacromial joint, or both. Glenohumeral motion and strength rely on intact joints and on the coordinated interplay of the muscles and tendons around the shoulder. Contraction of the muscles of the rotator cuff creates a stabilising compressive force, with a down...

Examination was made of 486 skeletons of subjects over the age of 60 years to study patterns of degenerative change in the glenohumeral joint. Three distinct types were found. Useful clinical implications are drawn from these distinctions.

CLINICAL SCENARIO It has been suggested that posterior shoulder tightness is a common contributor to shoulder impingement in overhead-throwing athletes. The incidence of shoulder pain in the general population has been reported to be as high as 27%, and as many as 74% of the patients who were seen for shoulder issues had signs of impingement. Particularly regarding physically active adults, sho...