Arm · Nerve
Radial Nerve
The radial nerve runs down the back of the arm and controls the muscles that straighten the elbow, wrist and fingers. Damage can cause "wrist drop".
What it is
The radial nerve is a major nerve of the arm, spiralling around the humerus (upper arm bone) on its way to the forearm and hand.
Where it runs
Down the back of the upper arm, around the humerus, into the back of the forearm and hand.
What it does
Controls the muscles that straighten the elbow, wrist and fingers, and carries sensation from the back of the hand.
When things go wrong
Common problems affecting the radial nerve
- "Saturday night palsy" (nerve compression causing wrist drop)
- Injury with upper-arm fractures
Education and reference only. This explains the anatomy in plain terms and is not a diagnosis. New weakness or numbness, facial drooping, or loss of bladder or bowel control can be an emergency — call 999.
Did you know?
An interesting fact
"Saturday night palsy" describes radial nerve compression from resting the arm over a hard edge while asleep, causing a temporary wrist drop.
Answers
Radial Nerve: frequently asked questions
What is wrist drop?
Wrist drop is difficulty lifting the wrist and fingers, caused by radial nerve damage. Depending on the cause it often recovers, and a clinician can advise.
Related nerves
Explore arm nerves
Sources
Where this is drawn from
- NHS — Nervous system
- Gray's Anatomy for Students
- TeachMeAnatomy — nervous system
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