The shoulder complex is one of the most elaborated joints of our body, as it is formed by several bones (clavicle, scapula, humerus and sternum) that constitute different joints (sternoclavicular, acromioclavicular, glenohumeral, scapulothoracic). The clavicle, also known as the collar bone, is an S-shape bone that forms the front of the shoulder, connecting to the sternum (sternoclavicular joint) and the shoulder blade (acromioclavicular joint). The thoracic outlet is a narrow space between the first rib, the scalene muscles (neck muscles), and the collar bone. Thoracic outlet syndrome is a medical umbrella term that refers to a series of conditions that compress the neuro-vascular structures passing through the thoracic outlet. There are several causes for the pressure in the thoracic outlet to increase, including anatomical abnormalities (anatomically narrow space, cysts, etc.), previous traumatic events (shoulder-neck injury such as clavicle fracture, etc.), poor posture, and in highly trained athletes, some muscles can increase the compression due to overuse (especially in overhead athletes, swimming, volleyball, baseball, etc). Patients affected by this condition typically present with a wide range of symptoms, that can be neural (pain, numbness, tingling, weakness, muscle loss), and vascular (swelling, cold sensation, loss of skin colour, pulsing and throbbing) driven. Aside from collecting data from the patient’s history and performing a physical (musculoskeletal and neural) assessment of the patient, an imaging examination (e.g.: x-ray, angiography, electrodiagnostic studies, etc) is typically recommended to optimally visualise the specifics of the condition.
