Thoracic Outlet Syndrome

picture from mountainhp

We had a Team Singapore cyclist who came to our clinic complaining of arm weakness, tingling sensations, pins and needles in his biceps and forearms after full on sprints. This did not happen during the sprints, but after. He also complained of neck pain and some sensations of electric currents in his neck region when he tried looking upwards.

picture from J Manip Phy Therapeutics

The doctor he saw at the Singapore Sports Institute diagnosed him with compartment syndrome in his arms. With compartment syndrome, as physical activity ceases, all symptoms should start to ease. My patient's discomfort and symptoms only started after he stopped sprinting.

Individuals with compartment syndrome will usually complain of pain, paraesthesia (or pins and needles), their limbs (usually legs) being very tight, tense and full of pressure during training or doing the offending activity. Temporary paralysis can occur sometimes. It usually happens to athletes at the start of the season, after their break when they train too hard, too soon. 

During exertion, the muscles expand and they fill up the space in the legs and "squeeze" the nerves and blood vessels there leading to sensations of tightness, pressure or pins & needles as the connective tissue that separates each section or compartment does not stretch hence leading to the term.

My patient probably has thoracic outlet syndrome (TOS) instead of compartment syndrome. TOS occurs when blood vessels or nerves in the space between the collar bone and first rib (this space is known as the thoracic outlet) are compressed causing neck, shoulder and arm pain and numbness in the arms and fingers.

There are a few types of TOS. My patient probably has the most common version known as neurological TOS, when the brachial plexus is compressed. The brachial plexus is a big network of nerves from the spinal cord and it controls muscle movements in the shoulder, arm and hand.

A common area where TOS occurs is in the interscalene triangle (formed by the brachial plexus, the subclavian artery exiting the neck area between the anterior and medial scalene muscles and the inner surface of the first rib). 

Brachial plexus

Entrapment in the interscalene triangle may be due to brachial plexus passing through the anterior scalene (especially when the anterior scalene is larger). In my patient's case, since he is a track cyclist (with bulging neck and arm muscles) who sprints in a velodrome with excessive traction forces while sprinting plus deadlifting and snatching the Olympic bar during weight training, all these factors could very well contribute to his TOS.

After a detailed questioning and physical assessment, we managed to treat his spine and and the nerves in that region. That cyclist was able to train without the accompanying pain and symptoms after.

Reference

Dahlstrom KA, and Oliver AB (2012). Descriptive Anatomy Of The Interscalene Triangle And The Costoclavicular Space And Their Relationship To Thoracic Outlet Syndrome: A Study of 60 Cadavers. J Manip Physiol Therapeutics. 35(5): 396-4001. DOI: 10.1016/jmpt.2012.04.017