Thoracic Outlet Syndrome: Biomechanical and Exercise Considerations

Abstract

Thoracic outlet syndrome (TOS) describes a group of disorders that are due to a dynamic compression of blood vessels or nerves, between the clavicle and first rib or cervical vertebral nerve roots. Individuals with TOS typically experience upper limb pain, numbness, tingling, or weakness that is exacerbated by shoulder or neck movement. The causes of TOS vary, and can include abrupt movements, hypertrophy of the neck musculature, and anatomical variations in which the brachial plexus roots pass through this musculature, edema, pregnancy, repeated overhead motions, the blockage of an artery or vein, or abnormal posture. To understand the complexity of this condition, an analysis of shoulder anatomy and mechanics are needed to help describe limitations and the subsequent pathophysiology of TOS. Several treatment options are available, including surgery, medications, and exercise. A comprehensive study of shoulder anatomy and biomechanics, and knowledge of the benefits of exercise, may help clinicians and healthcare practitioners determine the most appropriate treatment plan for an individual with TOS.

Keywords: functional anatomy; hypermobility; joint; ligament; mechanics; muscle; shoulder.

Figure 1

The force-length relationship characteristics for skeletal muscle.

Figure 2

Demonstration of scapular retraction and depression in the (a) start position; (b) end position of scapular retraction; (c) end position of scapular depression. For scapular retraction, emphasis is placed on “pulling” the shoulder blades backwards. For scapular depression, emphasis is placed on “pulling” the shoulders back and down.

Figure 3

Demonstration of standing external rotation in the (a) start position; (b) end position. Hands are pronated and elbows are flexed to approximately 90°. Pull the band apart, while focusing on retracting the scapula.

Figure 4

Demonstration of banded straight arm extension in the (a) start position; (b) end position. Arms start either elevated or parallel with the ground. The elbows stay slightly flexed, and the hands are brought down to the thigh while keeping the arms straight.

Figure 5

Demonstration of banded high pull in the (a) start position; (b) end position. The scapula is required first to be retracted and depressed. The band is then pulled to the chest.

Figure 6

Demonstration of prone shoulder extension, abduction, and horizontal abduction in the (a) start position; (b) end position for extension; (c) end position for abduction; (d) end position for horizontal abduction. The goal in performing these exercises is to keep the scapula flush against the rib cage while moving through the various shoulder motions. This shows a modified version, utilizing a bench if a table is not available.

Figure 7

Demonstration of frontal raise and lateral raise in the (a) start position; (b) end position for frontal raise; (c) end position for lateral raise. Brace the abdominal muscles and slowly raise and lower the weight.

Figure 8

Demonstration of serratus push in the (a) start position; (b) end position. Hold the bar further than shoulder width. The goal is to avoid excessive horizontal adduction, while keeping the arms straight and pushing the bar upwards.

Figure 9

Demonstration of chin tuck in the (a) start position; (b) end position. The goal is to tuck the chin and “push” the chin into the body.