If 10 people came to my office with their symptoms being numbness and tingling in the hands, most of them would assume they have carpal tunnel syndrome, but in fact only 1 of the ten would.  The other nine would have other conditions, the most common of which would be "Thoracic Outlet Syndrome"  First, the nerve roots that exit between each vertebrae can get pinched and irritated if the joints of the neck  are locked up.  This alone can cause pain into the hands and arms, but most patients with thoracic outlet have the nerve pinched at a few places. Chiropractic adjustments can be used to loosen these stuck joints and take the pinch off of the nerve.
pic of nerve roots leaving the spine. no muscles yet.
pic of the brachial plexus through the scalenes and the pecs The second area to pinch the nerves on their way down to the hand is the muscles of the neck called the scalenes. (In the picture at the left you can see the yellow nerves leaving the neck going between two neck muscles. These are the anterior and middle scalene muscles.)  Third, the pectoralis minor muscle can pinch the nerves. It is the muscle you can see to the left with the three attachments on the ribs.  These two muscles can be easily tested in our office to see if they are causing some of the arm and hand pain/ tingling and numbness. If they are also culprits, Dr. Ellis will perform special massage techniques and active release technique to loosen these muscles and teach stretches that can help speed the recovery at home.
Although this is not officially part of the thoracic outlet syndrome, Dr. Ellis checks for restrictions in the pronator teres muscle because as you can see from the picture on the right, the median nerve goes right between the two heads of this muscle.  If this muscle became tight and knotted up, you can see how it could put a real grip on the nerve.  Interestingly, the median nerve is the nerve that gets pinched in the carpal tunnel so it would be easy to get a misdiagnosis of carpal tunnel if this muscle was the actual underlying cause.
picture of pronator teres and median nerve
It is much more rare, but can be the cause of thoracic outlet syndrome is the presence of a cervical rib. (plus it's just fun to add this cool picture in here) Only about 1 out of 135 people have a rib coming off their neck and attaching to the sternum.  But if you have one, it could be causing the nerve to travel up over the rib on it's way down to the arm.  This could contribute to the nerve getting pinched.  However, hopefully conservative, chiropractic care will fix the joint and muscle problems so that whatever problem the cervical rib is causeing won't be enough to cause symptoms by itself.