[Functional motor innervation of brachial plexus roots: an intraoperative electrophysiological study].

The electrophysiological properties of normal brachial plexus and functional motor innervation during the operation of contralateral healthy side C7 transfer were studied different roots of brachial plexus were stimulated and maximum amplitudes were recorded. The results showed functional motor innervation of brachial plexus roots are (1)C5 mainly forms the axillary nerve which innervates deltoid muscle; (2)C5 constructs most of the musculocutaneous nerve fibers which innervate biceps muscle; (3)main component of the radial nerve comes from C7, which innervates triceps muscle; (4)Medial nerve mainly comes from C8, which innervates flexor digitorum muscle; (5)T1 forms most of the ulnar nerve which innervates intrinsic muscle. Based on the relationship between brachial plexus roots and their functional distribution, the particular aspects of functional innervation of C7 as well as the possibility of utilization of other cervical roots were discussed.