Thoracic Outlet Syndrome
Thoracic Outlet Syndrome
What isThoracic Outlet Syndrome (TOS)?
Firstly, to understand what TOS is, we need to determine where the Thoracic Outlet (TO) and Brachial Plexus are.
The TO is the name given to the space between the collarbone and first rib. It comprises of blood vessels, nerves and muscles. The Brachial Plexus is a network of nerves that send signals from the spinal cord to the shoulder, arm and hand.
TOS is a collection of disorders that occur when the blood vessels or nerves in the Thoracic outlet are compressed.
TOS was the term proposed by Peet et al. (1956) in order to summarise all of the symptoms caused by the compression of the neurovasuclar bundle.
There are 3 Types of Thoracic Outlet Syndrome
Neurological TOS: This is the most common and accounts for 90-95% of all TOS cases. It is the compression of the brachial plexus.
Venous TOS: This accounts for 5-10% of total cases. It is the compression of one or more of the veins under the collarbone,
Arterial TOS: This is rare. It is the compression of the the subclavian artery which leads to reduced blood flow to the upper limb.
Symptoms of TOS:
These can vary in nature depending on the type of TOS.
-Neurological TOS:
-Numbness/tingling in the arm or fingers
-Pain in the neck, shoulder, arm, hand
- Weak grip
Venous TOS:
Discolouration of the hand (may appear bluish)
Arm swelling
Arm pain
Arm fatigue with activity
Blood clot in the veins in the upper region of the body
Pale or abnormal colour of the fingers
Throbbing lump near the collarbone
Arterial TOS:
Cold fingers, hands, arm
Hand and arm pain
Lack of colour in hand/ fingers
Weak or no pulse in the affected arms
What are the risk factors:
These can be divided into intrinsic and extrinsic.
Intrinsic factors include: an extra first rib, a previous collarbone fracture which reduces the space for the nerves and vessels, boney or soft tissue abnormalities, muscle hypertrophy (enlargement) of the pectorals minor muscle, sex (females are 3 times more likely to have TOS than males), Age (more prevalent between 20-50 years old)
Extrinsic factors include: Trauma, poor posture, overhead receptive movements (sports, overhead heavy weight lifting)
Diagnosis:
There are certain tests that a physiotherapist can perform to test for TO, namely Adson’s, Roos and Wright’s Tests. These tests involve the intentional compression of certain structures which can cause reproduction of the symptoms. If a neurological TOS is determined this can be teated with physio exercise which involve stretching and mobilising structures to open up the TO. If venous or arterial TOS is determined then onward referral to a specialist will be made and xrays, ultrasounds scans will be performed.
Prevention:
To avoid unnecessary stress on the shoulders and muscles surrounding the TO is is advised to:
Maintain good posture
Maintain a healthy weight
Take frequent breaks whilst at work to move and stretch
Ensure proper set up of the work area to allow for good posture
Practice relaxation exercises such as diaphragmatic breathing, stretching, mobility.
References:
Jones M. R., Prabhakar A., Viswanath O., Urits I., Green J. B., Kendrick J. B., et al. (2019). Thoracic Outlet Syndrome: A Comprehensive Review of Pathophysiology, Diagnosis, and Treatment. Pain Ther. 8, 5–18. 10.1007/s40122-019-0124-2 [PMC free article] [PubMed] [CrossRef] [Google Scholar]
Peet R. M., Henriksen J. D., Anderson T. P., Martin G. M. (1956). Thoracic-outlet Syndrome: Evaluation of a Therapeutic Exercise Program. Proc. Staff Meet. Mayo Clin. 31, 281–287. [PubMed] [Google Scholar]
Katirji B., Hardy R. W. (1995). Classic Neurogenic Thoracic Outlet Syndrome in a Competitive Swimmer: a True Scalenus Anticus Syndrome. Muscle Nerve 18, 229–233. 10.1002/mus.880180213 [PubMed] [CrossRef] [Google Scholar]
Ohman J. W., Thompson R. W. (2020). Thoracic Outlet Syndrome in the Overhead Athlete: Diagnosis and Treatment Recommendations. Curr. Rev. Musculoskelet. Med. 13, 457–471. 10.1007/s12178-020-09643-x [PMC free article] [PubMed] [CrossRef] [Google Scholar]
Ozcakar L., Inanici F., Kaymak B., Abali G., Cetin A., Hasçelik Z. (2005). Quantification of the Weakness and Fatigue in Thoracic Outlet Syndrome with Isokinetic Measurements. Br. J. Sports Med. 39, 178–181. 10.1136/bjsm.2004.013706 [PMC free article] [PubMed] [CrossRef] [Google Scholar]