What is the primary myotome for S2?

The primary myotome for S2 is associated with plantarflexion. Myotomes are areas of muscle that are innervated by specific spinal nerves. S2 plays a critical role in the function of muscles involved in plantarflexion, primarily through its contributions to the tibial nerve, which innervates muscles like the gastrocnemius and soleus. These muscles are responsible for the action of pointing the toes and pushing the foot down, which is essential for activities such as walking and running.

Understanding that S2 is primarily responsible for plantarflexion helps clarify the significance of this myotome in functional movements. The other choices relate to movements primarily associated with other spinal nerves; for example, dorsiflexion is primarily innervated by L4-L5 nerves, knee extension by L2-L4, and hip flexion by L2-L3. Therefore, recognizing the specific myotome functions is vital for clinicians in assessing nerve root injuries and understanding lower limb function.