A myotome is a group of muscles that a single spinal nerve root innervates. Each myotome corresponds to a specific segment of the spinal cord, allowing for the control of muscle movement in different parts of the body. Understanding myotomes is essential in diagnosing nerve injuries and conditions affecting muscle function. Myotomes are often tested in clinical settings to assess motor function. For example, the C5 myotome controls the shoulder muscles, while the L4 myotome affects the muscles in the lower leg. This mapping helps healthcare professionals identify which nerves may be damaged or compromised.