Trapped nerves

Nerves supply the organs, muscles and other body tissues with information from the brain in the form of electrical impulses.
 
At various places along the nerve pathways to the upper limbs, nerves can get trapped. Possible sites of nerve entrapment due to tendon or muscle inflammation include the wrist, arms, neck and shoulder. It is even possible for nerves to get compressed in more than one location at the same time; a "double-crush".
 
Research carried out at University College London by physiotherapist Jane Greening and neurologist Dr Bruce Lynn has shown that nerves also need to slide freely between muscles and other tissue. In some patients however this nerve mobility during limb movement was greatly reduced, providing further signs of an identifiable pathology in cases of diffuse RSI pain.
 
Both these phenomena require great discernment from the doctor to understand the source of the problem, as nerve restrictions may occur at any point throughout the upper limb (not just at the carpal tunnel).