Rehabilitating the canine shoulder: a practical guide

The shoulder is the most mobile joint of the canine appendicular skeleton. The majority of the available movement is within a sagittal place (flexion and extension), however there is also a degree of rotation, both internal and external, adduction and abduction (Marcellin-Little et al, 2007). This wide range of motion is afforded by the ball and socket nature of the joint, formed by the glenoid cavity and humeral head. Stability of the shoulder joint is offered by the tough, fibrous joint capsule. This comprises the medial and lateral glenohumeroid ligaments and tendons from large surrounding muscles, located inside or outside the joint capsule (Sidaway et al, 2004).

The shoulder joint is comparatively challenging to examine thoroughly because of the bulk of soft tissue coverage surrounding it and the difficulty in isolating it as the source of pain without inadvertently stressing the elbow at the same time. During physical examination, the surrounding soft tissues should be evaluated for signs of discomfort and asymmetry, and the joint for available range and pain response during flexion and extension. It is also important to assess the shoulder for signs of instability. This is performed by assessing cranio-caudal and medio-lateral movement of the proximal humerus relative to the distal scapula (Marcellin-Little et al, 2007). The biceps tendon should also be assessed by palpation, and by extending the elbow with the shoulder in a flexed position (Bruce et al, 2000). Medial shoulder instability should be ruled in or out by assessing the level of available abduction, which is normally around 30° (Henderson et al, 2015).