Human Anatomy - Kotsan I. Ya. 2009

General overview of the muscles responsible for movements of individual body parts
Head movements
Muscles that perform movements at the atlanto-occipital joint

The following movements are possible in the occipital joint:

— HEAD extension (tossing the head back);

— head flexion (bending forward);

— lateral flexion of the head (to the right and left);

— head rotation (to the right and left).

Extension of the head occurs around a frontal axis passing through the atlanto-occipital joints. This function is performed by the following Muscles:

1) trapezius muscles;

2) splenius capitis muscles;

3) longissimus capitis muscles;

4) semispinalis capitis muscles;

5) rectus capitis posterior major muscles;

6) rectus capitis posterior minor muscles;

7) obliquus capitis superior muscles.

Flexion of the head, similarly to extension, occurs around the frontal axis passing through the atlanto-occipital joints. The Muscles responsible for head flexion include:

1) longus capitis muscles;

2) rectus capitis anterior muscles;

3) rectus capitis lateralis muscles;

4) suprahyoid and Infrahyoid muscles of the neck (with a fixed Mandible). Lateral flexion of the head occurs around the sagittal axis of the atlanto-occipital

joints. This movement is performed by the simultaneous contraction of the extensor and flexor muscles on the corresponding side, as well as the rectus capitis lateralis and longissimus capitis muscles.

Rotation of the head (to the right and left) occurs together with the first cervical vertebra (atlas) around the dens of the axis (vertebra dentata) within the median atlanto-axial and lateral atlanto-axial joints. The muscles that rotate the head include the following:

1) splenius capitis Muscle;

2) longissimus capitis muscle;

3) superior and inferior oblique Muscles of the head on the same side;

4) sternocleidomastoid muscle of the opposite side.