Look
Splints
Wasting
- triceps / extensor forearm
Arm up
- axilla / posterior / lateral elbow scars
Feel
Sensation
Axillary nerve - C5 / posterior cord
PCNFA
LCNF - C6 / Lateral Cord
SRN - C6 / Dorsal 1st Web
Median C6
- IF
State dermatomal or peripheral nerve
Move
Triceps C7
BR / ECRL - Radial Nerve
ECRB / EDC / EPL / EI - PIN
Supinator
- elbow extension to eliminate biceps, resist pronation
Special Tests
Tinels
DDx
C7 lesion
- triceps power / reflex lost
- good wrist extension (C6)
C6 lesion
- triceps intact
- wrist extension lost
Posterior cord
- radial nerve + axillary nerve + subscapularis + lat dorsi
Site of injury
High lesion / no triceps
- Saturday night palsy
Intermediate lesion / triceps intact / no BR or ECRL
- humeral fracture
Low lesion / PIN Compression (FREAS)
- fascial bands
- recurrent radial
- ECRB
- arcade of Frohse
- exit supinator