THORACIC OUTLET SYNDROME
July 15, 2019

Thoracic Outlet Syndrome

The term ‘thoracic outlet syndrome’ describes compression of the neurovascular structures as they exit through the thoracic outlet (cervicothoracobrachial region).  Learn about thoracic outlet syndrome and how our specialized treatments can help relieve your symptoms and improve your quality of life.

3 Different regions where it could lead to a compression of the nerve. 

1.The first narrowing area is the most proximal and is named the interscalene triangle, near to the front of the neck between two fibers of the scalene

2.The second passageway is called the costoclavicular triangle which is bordered in-between the scapula, first rib, and the border of scapula.

3,.The last passageway is called the subcoracoid or sub-pectoralis minor space minor tendon. Shortening of the pecoralis minor muscle can lead to a narrowing of the passage thereby compressing the neurovascular structures during excessive arm movements.

Certain anatomical abnormalities can be potentially compromising to the thoracic outlet as well. These include the presence of a cervical rib, congenital soft tissue abnormalities, clavicular hypomobility, and functionally acquired anatomical changes.

Thoracic outlet syndrome Causes:

Congenital factors


• Cervical rib
• Prolonged transverse process
• Anomalous muscles 
• Fibrous anomalies (transversocostal, costocostal)
• Abnormalities of the insertion of the scalene muscles
• Fibrous muscular bands.
• Exostosis of the first rib 
• Cervicodorsal scoliosis.
• Congenital uni- or bilateral elevated scapula 
• Location of the A. or V. Subclavian in relation to the M. scalene anterior

Acquired conditions


• Postural factors
• Dropped shoulder condition.
• Wrong work posture (standing or sitting without paying attention to the physiological curvature of the spine) 
• Heavy chested.
• Trauma.
• Clavicle fracture.
• Rib fracture.
• Hyperextension neck injury, whiplash. 
• Repetitive stress injuries (repetitive injury most often form sitting at a keyboard for long hours.


Muscular causes


• Hypertrophy of the scalene muscles 
• Decrease of the tonus of the M. trapezius, M. levator scapulae, M.rhomboids 
• Shortening of the scalene muscles, M. trapezius, M. levator scapulae, pectoral muscles

Characteristics/Clinical Presentation

Signs and symptoms of thoracic outlet syndrome vary from patient to patient due to the location of nerve and/or vessel involvement. Symptoms range from mild pain and sensory changes to limb threatening complications in severe cases.

Patients with thoracic outlet syndrome will most likely present pain anywhere between the neck, face and occipital region or into the chest, shoulder and upper extremity and paresthesia in upper extremity. The patient may also complain of altered or absent sensation, weakness, fatigue, a feeling of heaviness in the arm and hand. The skin can also be blotchy or discolored. A different temperature can also be observed.

Signs and symptoms are typically worse when the arm is brought overhead and externally rotated with the head rotated to the same or the opposite side. As a result activities such as overhead throwing, serving a tennis ball, painting a ceiling, driving, or typing may exacerbate symptoms. [21][23]

When the upper plexus (C5,6,7) is involved there is pain in the side of the neck and this pain may radiate to the ear and face. Often the pain radiates from the ear posteriorly to the rhomboids and anteriorly over the clavicle and pectoralis regions. The pain may move laterally down the radial nerve area. Headaches are not uncommon when the upper plexus is involved.

Patients with lower plexus (C8,T1) involvement typically have symptoms which are present in the anterior and posterior shoulder region and radiate down the ulnar side of the forearm into the hand, the ring and small fingers. [24][2]

Diagnostic Procedures 

The diagnosis of TOS is essentially based on history, physical examination, provocative tests, and if needed ultrasound, radiological evaluation and electrodiagnostic evaluation. It must always kept in mind that TOS diagnosis is usually confirmed by elimination of other causes with similar clinical presentation. Especially differential diagnosis of cervical radiculopathies and upper extremity entrapment neuropathies can be hard (McGillicuddy 2004). [26][28] In order to diagnose accurately, the clinical presentation must be evaluated as either neurogenic (compression of the brachial plexus) or vascular (compression of the subclavian vessels). TOS manifestations are varied and there is no single definitive test, which makes it difficult to diagnose. [21][24]

  • Neurological Screen
  • MMT & Flexibility of following muscles:

– Scalene 
– Pectoralis major/minor 
– Levator scapulae 
– Sternocleidomastoid 
when the lateral flexion movement is blocked. 

Physical Therapy Management 

Conservative management should be the first strategy to treat TOS since this seems to be effective at decreasing symptoms, facilitating return to work and improving function, but yet a few studies have evaluated the optimal exercise program as well as the difference between a conservative management and no treatment.[36] Level of evidence 1A Conservative management includes physical therapy, which focuses mainly on patient education, paincontrol, range of motion, nerve gliding techniques, strengthening and stretching.

 The aim of the initial stage is to decrease the patient’s symptoms. This may be achieved by patient education, in which TOS, bad postures, the prognosis and the importance of therapy compliance are explained. Furthermore some patients who sleep with the arms in an overhead, abducted position should get some information about their sleeping posture to avoid waking up at night. These patients should sleep on their uninvolved side or in supine, potentially by pinning down the sleeves. Also cervical traction in combination with a hot pack and light exercise may reduce pain and irritable symptoms for some acute patients.

Looking for physiotherapy for thoracic outlet syndrome in Mississauga? Our expert team is here to provide specialized treatment and relieve your symptoms. Contact us today to schedule an appointment.