What is the damage nerve results in wristdrop?

The damage of the radial nerve results in wristdrop. The radial nerve, which runs from the shoulder down the back of the upper arm and forearm, supplies movement to the triceps muscle (at the back of the upper arm) and the wrist extensor muscles (on the back of the forearm). Damage to this nerve can cause weakness or paralysis of these muscles, resulting in wristdrop, a condition where the wrist is unable to be extended upward and the hand hangs down limp. The radial nerve can be damaged through various means such as fractures or dislocations of the elbow joint, lacerations, compression, or stretching injuries.