The upper (superior) subscapular nerve is the first branch of the

posterior cord The posterior cord is a part of the brachial plexus The brachial plexus is a network () of nerves formed by the anterior rami of the lower four cervical nerves and first thoracic nerve ( C5, C6, C7, C8, and T1). This plexus extends from the ...

of the

brachial plexus The brachial plexus is a network () of nerves formed by the anterior rami of the lower four cervical nerves and first thoracic nerve ( C5, C6, C7, C8, and T1). This plexus extends from the spinal cord, through the cervicoaxillary canal in th ...

. The upper subscapular nerve contains

axons An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see spelling differences), is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action po ...

from the

ventral rami The ventral ramus (pl. ''rami'') (Latin for ''branch'') is the anterior division of a spinal nerve. The ventral rami supply the antero-lateral parts of the trunk and the limbs. They are mainly larger than the dorsal rami. Shortly after a spinal ...

of the C5 and C6 cervical

spinal nerves A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into th ...

. It innervates the superior portion of the

subscapularis muscle The subscapularis is a large triangular muscle which fills the subscapular fossa and inserts into the lesser tubercle of the humerus and the front of the capsule of the shoulder-joint. Structure It arises from its medial two-thirds and S ...

. The inferior portion of the subscapularis is innervated by the lower subscapular nerve.

Structure

The

which form the upper subscapular nerve travel from the

of C5 and C6. They join at the

upper trunk The upper (superior) trunk is part of the brachial plexus. It is formed by joining of the ventral rami of the fifth (C5) and sixth (C6) cervical nerves. The upper trunk divides into an anterior and posterior division. The branches of the upper tru ...

and move through its posterior division to form the

, along with the other two posterior divisions of the middle and lower trunks. The axons then branch from the posterior cord and form the upper subscapular nerve.

Function

The upper subscapular nerve innervates the superior portion of the

Clinical significance

A lesion to the upper subscapular nerve can cause a reduced ability to medially rotate at the shoulder joint, however this function is supplemented by other muscles.

Additional images

File:Brachial plexus.svg, Brachial plexus File:Gray809.png, The right brachial plexus (infraclavicular portion) in the axillary fossa; viewed from below and in front.

References

Nerves of the upper limb {{Portal bar, Anatomy