Rectus capitis posterior major muscle

Rectus Capitis Posterior Major Muscle

The Rectus Capitis Posterior Major muscle is a small muscle located at the back of the neck. It is one of the deep muscles of the suboccipital region, along with the Rectus Capitis Posterior Minor, Obliquus Capitis Superior, and Obliquus Capitis Inferior muscles. In this article, we will explore the anatomy, function, and clinical significance of the Rectus Capitis Posterior Major muscle.

Anatomy

The Rectus Capitis Posterior Major muscle originates from the spinous process of the axis (C2) vertebra, which is the second cervical vertebra. It then inserts onto the lateral part of the inferior nuchal line of the occipital bone, which is the bony ridge at the base of the skull.

The muscle is innervated by the suboccipital nerve, which is a branch of the dorsal ramus of the first cervical nerve (C1). The blood supply to the Rectus Capitis Posterior Major muscle is provided by branches of the occipital artery.

Function

The main function of the Rectus Capitis Posterior Major muscle is to extend the head at the atlanto-occipital joint. This means that it helps to tilt the head backward, as if looking up towards the ceiling. Additionally, it also assists in rotating the head to the same side.

Clinical Significance

The Rectus Capitis Posterior Major muscle can be involved in various clinical conditions, including:

1. Suboccipital headache: Dysfunction or tension in the suboccipital muscles, including the Rectus Capitis Posterior Major, can lead to headaches localized at the back of the head. These headaches may be accompanied by neck pain and restricted range of motion.

2. Whiplash injuries: In cases of whiplash, where the head is forcefully thrown forward and backward, the Rectus Capitis Posterior Major muscle can be strained or injured. This can result in pain, stiffness, and limited movement of the neck.

3. Cervical spine disorders: Dysfunction of the cervical spine, such as cervical spondylosis or herniated discs, can affect the Rectus Capitis Posterior Major muscle. This can lead to muscle imbalances, pain, and restricted neck movements.

Related Muscles

The Rectus Capitis Posterior Major muscle is closely related to other muscles in the suboccipital region. These include:

1. Rectus Capitis Posterior Minor: This muscle lies just anterior to the Rectus Capitis Posterior Major and has a similar function of extending and rotating the head.

2. Obliquus Capitis Superior: Located above the Rectus Capitis Posterior Major, this muscle also contributes to head extension and rotation.

3. Obliquus Capitis Inferior: Positioned below the Rectus Capitis Posterior Major, this muscle assists in head rotation and lateral flexion.

References

1. Drake, R. L., Vogl, W., & Mitchell, A. W. (2014). Gray's anatomy for students. Elsevier Health Sciences.

2. Standring, S. (Ed.). (2016). Gray's anatomy: the anatomical basis of clinical practice. Elsevier Health Sciences.

See Also

• Suboccipital Muscles
• Cervical Spine
• Whiplash Injury