A terminal branch of the posterior cord. Most superficial part of the plexus. Seen with penetrating wounds of the neck. Destruction of the C5 and C6 root supply leaves the patient with loss of sensation of the lateral upper arm, forearm, and hand. A middle trunk injury is equivalent to a C7 nerve root injury.
Weakness is found in the triceps, wrist flexors and extensors, and latissimus dorsi.
C8 fibers to anterior division, medial cord, medial component to median nerve, then to flexor digitorum profundus supplying digits II and III. 2. C8 fibers to posterior division, then to posterior cord, radial nerve, and then to extensor digitorum. Intrinsic muscles of the hand. T1 fibers to anterior division, then to medial cord, lateral component of median nerve, median nerve to thenar muscles and lateral two lumbricals. Essentially a combination of axillary and radial nerve injuries.