Nerve impingement of the brachial plexus, the nerves exiting the spine in the neck, can be the cause of numbness or tingling in the arm and / or hand. If the alteration of sensation is diffuse throughout the upper extremity, all or most of the nerves in the brachial plexus may be affected, sometimes due to impingement between the clavicle and the first rib, or in passage between the scalene muscles at the sides of the neck. However, if only parts of the arm or hand are affected, it may be possible to pinpoint the specific spinal nerves that are being impinged. This can guide the specific Activator Chiropractic adjustment which can help alleviate the problem.