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. Myotomes are essential for understanding how nerves affect muscle function and are often used in clinical assessments to diagnose nerve injuries or conditions. In humans, there are 31 pairs of spinal nerves, and each pair contributes to different myotomes. For example, the cervical myotomes control muscles in the neck and arms, while the lumbar myotomes influence muscles in the lower back and legs. Understanding myotomes helps in rehabilitation and physical therapy.