Anatomy & Organs

Musculus rectus capitis lateralis – structure, function & diseases

Lateral rectus muscle

Skeletal muscles are particularly important to the human body because they allow us to move freely.

They are responsible for movements that the body performs voluntarily and actively, for example the movement of the arms and legs . They also belong to striated muscles because they have fine transverse stripes that create a periodic, repeating pattern. The rectus capitis lateralis muscle belongs to the striated muscles .

Was ist the lateral rectus muscle?

The term musculus rectus capitis lateralis is Latin and stands for “lateral straight head muscle”.

This muscle is small, short, and flat, located at the side of the first cervical joint in the deep neck. It belongs to the secondary back musculature , but not to the autochthonous back musculature (“local back musculature”), since it is intervened by the anterior ramus; however, the rectus capitis lateralis muscle also belongs to the neck muscles. The origin of the rectus capitis lateralis muscle is the so-called transverse process (processus transversus) of the first cervical vertebra . Transverse processes are paired bone tissues of a vertebra.

Anatomy & Structure

The rectus capitis lateralis muscle belongs to the striated muscles and is therefore lined with a covering of connective tissue (fascia), which also encloses some meat fibers.Each of these meat fibers can be divided into several fiber bundles, which are also called primary bundles: These are stored in such a way that they can move one another, so the muscle is flexible and adaptable. The primary bundle consists of twelve muscle fibers, which are connected by connective tissue and thin, fine blood vessels .

The “lateral straight head muscle” becomes active by tensing, thus contracting and shortening. It is then relaxed again and the muscle is lengthened ( relaxation ). Shortening of the muscles is triggered when the brain or spinal cord conducts electrical impulses along the nerves .

A skeletal muscle is also called a syncytium. This is a cell made up of myoblasts and thus contains nuclei. The syncytium is incapable of division, which is why no new ones grow back when muscle fibers are lost and adjacent fibers only thicken. The rectus capitis lateralis muscle attaches to the jugular process on the neck, a bony process of the occipital bone (occipital bone), which forms the rearmost part of the skullcap.

Function & Tasks

The lateral rectus muscle has the task of assisting in the movement of the head, especially lateral movements. When the head tilts to one side, the small muscle shortens on one side and contracts.

With a contraction on both sides, a slight dorsal reflection of the head takes place: The short muscle allows the head to bend dorsally, ie towards the back . When the head moves forward, the rectus capitis lateralis muscle stretches (extension). As part of the secondary muscles of the back and neck, the lateral rectus capitis muscle assists in movement of the spine , particularly in extension.

Innervation refers to the supply of nerve tissue (e.g. nerve fibers and cells) to an organ, connective tissue or a body. Innervation controls processes and reactions in the body through perception of stimuli and excitement.

The rectus capitis lateralis muscle is also innervated by special nerve tissue, the anterior rami of the spinal nerves , which arise in pairs from the spinal cord. They are part of the peripheral nervous system , the nervous system that does not arise from the brain or spinal cord and is found outside the spinal canal or skull . The anterior rami arise from the C1 and C2 spinal cord segments, which are the first two sections of the spinal cord. The C1 and C2 innervation takes place in the lateral rectus capitis muscle and this muscle thus receives the necessary nerve tissue.


As part of the neck muscles, various complaints and diseases can occur in the rectus capitis lateralis muscle, such as neck tension, particularly caused by the small muscle.The biggest cause of neck tension these days is bad posture and stress in everyday life. Long-term office work can lead to a muscular imbalance and manifest itself in the form of neck tension. With Repetitive Strain Injury Syndrome, there is regular strain on the neck due to repetitive movements, which can put even more strain on the rectus capitis lateralis muscle and trigger tension throughout the body.

Back headaches can also be caused by neck tension, which can be triggered by the rectus capitis lateralis muscle. The causes of back headaches can vary widely, but neck muscle tension is likely.

In the case of tension, no medication is necessary, only heat and relaxation help here, so that the muscles can relax again and the tense position of the muscles relaxes. Cold and heat treatment can also prove helpful, as the rectus capitis lateralis muscle can come out of its shortened position and the tension can thus ease.

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.