CrossFit and Risk of Thoracic Outlet Syndrome

Thoracic Outlet Syndrome (TOS) can happen when blood vessels and nerves pass through a narrow area near the shoulder and collarbone on their way to the arms. Pressure on blood vessels and nerves can reduce blood flow and function in the arms and hands. Pressure can build from muscle hypertrophy, swelling from repetitive movement, overuse or can be the result of previous injuries. It can also happen in people with poor posture who slouch a lot. (That last one should not be Cross Fit related). Farmer Carries, Kettle Bells, Presses, etc. are possible triggers.  UPDATE: This post on Thoracic Outlet Syndrome has become one of the top posts for WODMasters.  I’m guessing TOS must be happening out there.  There doesn’t seem to be much conversation about Thoracic Outlet Syndrome in the CrossFit Community.  But . . . it seems like something that needs more awareness and attention.

Symptoms of thoracic outlet syndrome include:

•  Pain, numbness, and tingling in the pinky and ring fingers, and the inner forearm 
•  Pain and tingling in the neck and shoulders (pain my increase while or after carrying a heavy object as during a Farmer Carry) 
• Poor circulation in the hand or forearm (a bluish tinge or turn white, cold hands, or a swollen arm) 

Pull-up Master at CrossFit Seven, Fort Worth, TX.

• Weakened grip 

You should lay off shoulder exercises for a while. TOS can be dangerous. A friend and long-term weight lifter recently ended up in ICU with this condition. Severe blockage of a vein can cause severe swelling in an arm (or both arms if you are unfortunate to block both sides at the same time). This could cause blood clot to develop. The blood clot could potentially be fatal if it were to break off and cause a pulmonary embolism. Go see a doctor if you are having swelling or other signs of impaired blood circulation. There are two references below. These have been selected as most relevant to injuries that would be seen in athletes. TOS may be treated with drugs to dissolve a blood clot and in severe cases may involve removal of the first rib to relieve pressure on the vein.  

Duwayri YM, Emery VB, Driskill MR, Earley JA, Wright RW, Paletta GA Jr, & Thompson RW (2011). Positional compression of the axillary artery causing upper extremity thrombosis and embolism in the elite overhead throwing athlete. Journal of vascular surgery : official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter, 53 (5), 1329-40 PMID: 21276687