Myotome (upper limb)

 

A myotome is the group of muscles that a single spinal nerve root innervates. Similarly a dermatome  is an area of skin that a single nerve innervates. In vertebrate embryonic development, a myotome is the part of a somite that develops into the muscles.

Upper Limb Myotomes

Movement	Nerve Root Segments
Shoulder girdle elevation	C3/4
Shoulder flexion / abduction	C5
Elbow flexion	C5/6
Elbow extension	C7/8
Wrist flexion / extension	C6/7
Finger flexion / extension	C7/8
Finger abduction / adduction	T1