TOS or Thoracic Outlet Syndrome (Cervicobrachial Syndrome, Myogenic TOS, myofascial TOS, Scalenius Anticus)

The thoracic outlet is an area in the shoulder where the nerves and vessels travel.  Since these nerves go into the hand, when irritated, they can cause numbness and tingling as well as swelling and weakness.  Notice that the scalene muscles go from the neck to the ribs.  These muscles are commonly tight after a whiplash injury due to the loss of curvature in the neck.  Tight scalenes tend to close in the walls of the thoracic outlet and compress the nerves.  When these muscles are tight, the first rib (and 2nd/3rd) are pulled up, further closing down this space and making it even tighter for the nerves.  Finally, a forward shoulder can also cause this area to get tight.

Treatment is restoring the normal curve in the neck, promoting good posture through thoracic extension, manual stretching of the scalenes, and mobilization or manipulation of the first, second, and third ribs.  Treatment may also include aggressive manual stretching of the chest wall and nerves.  Testing is almost always false negative.   Most doctors will try to get an EMG/NCS, but this is usually normal and misses the diagnosis.  Finally, while surgery is an option in the most severe cases (less than 1%), it's not considered in the vast majority of patients with this problem.