What nerve is found in the posterior cord (posterior fascicle) of the brachial plexus?

From the Guidelines

The posterior cord (posterior fascicle) of the brachial plexus contains the radial nerve and the axillary nerve. These nerves are formed by the merging of the posterior divisions of the upper, middle, and lower trunks of the brachial plexus 1. The posterior cord is positioned behind the axillary artery and gives rise to the radial and axillary nerves. Key points about the nerves in the posterior cord include:

• The radial nerve is the larger terminal branch, supplying the posterior compartment of the arm and forearm
• The radial nerve provides motor innervation to the extensor muscles and sensory innervation to parts of the posterior arm, forearm, and hand
• The axillary nerve is the smaller terminal branch, supplying the deltoid and teres minor muscles
• The axillary nerve provides sensory innervation to the lateral aspect of the shoulder Understanding the composition of the posterior cord is crucial for diagnosing and treating injuries to the brachial plexus that may affect posterior arm and shoulder function, ultimately impacting morbidity, mortality, and quality of life 1.

From the Research

Nerve Found in the Posterior Cord of the Brachial Plexus

The nerve found in the posterior cord (posterior fascicle) of the brachial plexus is the radial nerve.

• The radial nerve is a branch of the posterior cord of the brachial plexus, as stated in the study 2.
• It innervates muscles such as the triceps, anconeous, brachialis, brachioradialis, and extensor carpi radialis longus, and gives off branches like the posterior cutaneous nerve of the arm, lower lateral cutaneous nerve of arm, and posterior cutaneous nerve of forearm 2.
• The posterior cord is also involved in other studies, including the transfer of nerve fascicles for lesions of the posterior cord in infraclavicular brachial plexus injury 3, and hourglass-like constriction of the brachial plexus in the posterior cord 4.
• Variations in the terminal branches of the brachial plexus, including the posterior cord, have been identified, highlighting the importance of considering these variations in clinical practice 5.