What is the innervation of the Multifidus muscle?

The Multifidus muscle is primarily innervated by the dorsal rami of spinal nerves. This muscle is part of the intrinsic back muscles and plays a critical role in stabilizing the vertebral column, particularly during various movements and postural adjustments. The dorsal rami of the spinal nerves supply the muscle segments within the region they innervate, allowing for precise control and function.

The dorsal rami conduct sensory and motor innervation to the muscles and skin of the posterior aspect of the trunk, including the Multifidus. The muscle spans several vertebrae and assists in extension, rotation, and lateral flexion of the spine, highlighting the importance of its innervation for maintaining spinal stability and function.

While the other choices may reference various spinal nerve components, they do not specifically address the appropriate innervation of the Multifidus. In particular, the ventral rami are responsible for innervating the anterior trunk and extremities, while stating that the muscle is only innervated by cervical spinal nerves or both cervical and lumbar spinal nerves does not accurately reflect the broader anatomical innervation of the Multifidus, which encompasses multiple levels of dorsal rami.