Determining whether a patient’s symptoms are associated with a condition for which physical therapy intervention is indicated is one of the important questions physical therapists attempt to answer during an initial patient visit. This resident’s case problem involves a 34-year-old homemaker and long-distance runner referred for physical therapy with a diagnosis of right sacral pain. This case illustrates that the answer to this question may not be clear until subsequent patient visits occur. Sacral stress fractures, although relatively uncommon, are a potential source of back pain, which is a common complaint in patients seeking physical therapy outpatient services. Because bony lesions can be associated with serious medical conditions, such as cancers and fractures, early detection and an accurate diagnosis is paramount to appropriate care. An important element in screening for such conditions is recognizing patients with the relevant risk factors. The presence of the risk factors associated with insufficiency and fatigue fractures, as described in this case, should alert the therapist to scrutinize symptoms and signs suggestive of a bony lesion thoroughly. As described, there is an unfortunate degree of overlap of symptoms and signs for many of the conditions causing back pain and those of sacral stress fractures. Another important element of this screening process is establishing a prognosis that carries expectations of patient progression, both from a subjective and a physical examination standpoint. If these expectations are not met, the therapist must reconsider the original diagnosis, and, as in this case, insure that the patient is referred for physician follow-up and the recommended appropriate diagnostic workup. J Ortho Sports Phys Ther. 2002;32(12):613-621.

Study Design: Single-session repeated-measures design.

Objectives: To define the resting position of the glenohumeral joint by investigating the magnitude of the anterior and posterior displacements of the humeral head and medial and lateral rotation ranges of motion (ROMs) of the glenohumeral joint at different abduction angles in cadaver specimens.

Background and Purpose: The resting position of a joint is the position in the joint’s ROM at which the joint capsule has its greatest laxity. It is frequently chosen as the position for assessing and treating joints with dysfunction. However, no study has been conducted to determine the resting position of the glenohumeral joint.

Methods:Seven freshly frozen cadaver shoulder specimens (age at time of death [mean ± SD] was 66.9 ± 2.5 years) were studied. Specimens were mounted on a system that uses computer-controlled hydraulics and motors to induce and monitor translation and rotation movements of the glenohumeral joint. The magnitudes of total displacement (DTotal) of the head of the humerus and total ROM (RTotal) of the glenohumeral joint were measured in the plane of the scapula at 0° (neutral), 30°, 40°, 50°, 60°, and the end range of glenohumeral joint abduction. The resting position was determined as the midpoint of the shared range of the 95% to 99.9% confidence intervals of the predicted abduction position where the peaks of displacement and rotation occurred.

Results: The DTotal measurements (mean ± SD) at 0°, 30°, 40°, 50°, 60°, and the end range of glenohumeral joint abduction were 30.53 ± 9.35, 44.87 ± 7.34, 45.35 ± 8.53, 43.99 ± 10.02, 39.63 ± 9.85, and 23.80 ± 10.42 mm, respectively. The RTotal measurements (mean ± SD) for the same positions were 67.15° ± 15.87°, 95.64° ± 24.26°, 98.88° ± 29.56°, 97.08° ± 30.17°, 90.91° ± 28.73°, and 63.48° ± 25.93°, respectively. The resting position was located at 39.33° ± 4.37° of glenohumeral abduction (45.13% ± 7.58% of the available abduction ROM). The resting position (Y) varied linearly with the maximum available abduction ROM (X) (Y=0.607X-13.120, R2=0.679, F=10.61, P=0.023). There was a main effect of joint position on both displacement (P<0.001) and rotation ROM (P<0.001).

Conclusion: In the plane of the scapula, the resting position of the glenohumeral joint (angle measured between the scapula and humerus) occurred at 39° of abduction (45% of the maximum available abduction ROM) and varied linearly with the amount of available abduction ROM. This finding suggests that in patients with glenohumeral joint hypomobility the resting position is located closer to neutral and that evaluation and treatment should be initiated accordingly at a smaller angle of abduction than the traditional resting position. Our data were derived from cadaver specimens, therefore, caution should be taken when generalizing the results of the present study to a patient population.

J Ortho Sports Phys Ther. 2002;32(12):605-612.

Keywords: glenohumeral joint, laxity, shoulder, range of motion, resting position

Index by subject of all manuscripts published in the Journal during 2002.

J Orthop Sports Phys Ther. 2002;32(12):658-663.