Diaphragmatic referred pain

Nerve supply of diaphragm

Motor supply - phrenic nerve 

Sensory supply

Central tendon- phrenic nerve(ventral rami of c3,c4 and c5

Peripheral- lower 5 intercoastal nerve

Referred pain-

Sensory fibers which supply the diaphragm and enter the cord at the C 3, 4 and 5 segments. This segment of the cord also supply's the supraclavicular nerves (medial, intermediate and lateral) via the cervical plexus. The lateral supra-clavicular nerve supply's the skin directly over the acromium process. Irritation of the diaphragm can be experienced as pain over the acromium process.