Wrist Drop (�Saturday Night Palsy�)
results from loss of the radial nerve. The radial nerve is known as the �great extensor nerve.� It innervates the posterior compartments of the arm and forearm which contain extensor muscles. The symptoms resulting from the loss of this nerve depends on how high the lesion is. If the injury occurs in the axilla, then the triceps will be affected and extension at the elbow will be lost in addition to extension at the wrist and fingers (at MP joints). If the injury is lower (in the arm), the wrist drop and loss of finger extension (at MP joints) will result.