Dermatomal nerve generally refers to the musculocutaneous nerve, which is the main nerve of the upper arm, and its injury recovery usually takes 3~6 months, depending on the degree of dermatomal nerve injury. 1. Musculocutaneous nerve contusion, if the contusion is minor and the nerve is not severed, it usually takes 3 months to recover, during which nutritive drugs can be applied to the nerve, along with appropriate physical therapy, combined with functional exercises, and so on. 2. If the injury to the musculocutaneous nerve is more serious, such as heavy contusion or nerve fracture, it usually takes 6 months to recover. During this period, we should pay attention to our own sensory recovery, because the musculocutaneous nerve is mainly a sensory nerve. After myocutaneous nerve injury, you should go to a regular hospital as soon as possible to assess the location and extent of the injury, and cooperate with the appropriate treatment and rehabilitation training, the general prognosis is good.