Klumpke's palsy is due to injury to the following nerves:
The upper trunk (C5 and C6) is the most common area injured and results in the classic Erb palsy. Injury to the lower trunk (C7-T1) produces a Klumpke palsy. Klumpke palsy is characterized by good shoulder function but decreased or absent hand function. Brachial plexus injuries may also cause a Horner syndrome (unilateral miosis, ptosis, and facial anhidrosis) due to disruption of cervical sympathetic nerves. Ref: Wilson P.E., Clayton G.H. (2012). Chapter 28. Rehabilitation Medicine. In W.W. Hay, Jr., M.J. Levin, R.R. Deterding, J.J. Ross, J.M. Sondheimer (Eds), CURRENT Diagnosis & Treatment: Pediatrics, 21e.
Inferior trunk of the brachial plexus
Superior trunk of the brachial plexus
Subscapular nerve
Ulnar nerve