The complexus muscle, also known as the complexus cervicis, is a deep and complex muscle located within the neck region. It is part of the group of muscles known as the suboccipital muscles. The complexus muscle is specifically situated deep to the semispinalis capitis muscle and lateral to the rectus capitis posterior major and minor muscles.
The complexus muscle originates from the transverse processes of the upper cervical vertebrae, including C1, C2, and C3. From its origin, the muscle ascends and inserts onto the lateral part of the occipital bone, specifically at the inferior nuchal line.
This muscle plays a crucial role in the movement and stabilization of the head and neck. It acts as a synergist to other muscles in the region, aiding in extension, lateral flexion, and rotation of the cervical spine. The complexus muscle predominantly assists in maintaining the alignment and balance of the head on top of the cervical spine during various movements.
In addition to its primary function, the complexus muscle also contributes to proprioception, which is the body's ability to sense its position and movement in space. This muscle receives sensory information from various muscle spindles and helps in coordinating and fine-tuning motor responses.
Due to its deep location and intricate connections, the complexus muscle can be difficult to specifically isolate or target during clinical examination or therapeutic intervention. However, understanding its anatomical structure and functional importance is vital for medical professionals and therapists dealing with issues related to the head, neck, and cervical spine.
