Neurology Lab 3 - Module 1 - Deep Back and Suboccipital Triangle: Page 2 of 2
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The Erector Spinae Muscles
| Add the spinalis group. The thoracis component of this muscle group is the only part shown. The capitis and cervicis often blend with the fibers of the semispinalis and ligamentum nuchae. |
| Add the ligamentum nuchae. The thoracis component of this muscle group is the only part shown. The capitis and cervicis often blend with the fibers of the semispinalis and ligamentum nuchae. |
| Add the longissimus group. |
| Add the iliocostalis group. |
The Spinotransversales Muscles
| Add the splenius group. |
The members of the deep back muscles function as follows:
- When working in equilibrium, they stiffen the spine so we can stand erect.
- When working unilaterally, they cause the spine to rotate in the direction of contraction.
- When all are contracting, they cause the spine to hyperextend posteriorly.