Upper-arm weakness (paresis) or paralysis indicates peripheral-nerve damage to the brachial plexus, a network of lower cervical and upper thoracic spinal nerves supplying the arm, forearm ...
[15] The posterior rami provide spine muscle and trunk skin sensation. The most complex nerve plexus is the brachial plexus, consisting of cervical nerves 5 through 8 (C5 to C8) and thoracic nerve ...