Multifidus Flashcards

Study the multifidus muscle, including its segmental attachments, regional anatomy, innervation, spinal actions, and stabilizing role.

Card 1 of 25Question

What is the multifidus muscle?

A deep intrinsic back muscle composed of short, overlapping fascicles that connect adjacent regions of the vertebral column.

In This Section

1. What is the multifidus muscle?

A deep intrinsic back muscle composed of short, overlapping fascicles that connect adjacent regions of the vertebral column.

2. To which group of intrinsic back muscles does the multifidus belong?

The transversospinalis group.

3. Which three muscles form the transversospinalis group?

Semispinalis, multifidus, and rotatores.

4. Where is the multifidus located relative to the semispinalis muscle?

Deep to semispinalis.

5. In which region of the vertebral column is the multifidus most developed?

The lumbar region.

6. What is the overall vertebral extent of the multifidus muscle?

From the posterior sacrum to the axis (C2), with fascicles distributed throughout the intervening vertebral regions.

7. What are the principal sacral attachments of the multifidus?

The posterior sacrum, posterior sacroiliac ligaments, and adjacent aponeurotic structures.

8. From which vertebral processes does the lumbar multifidus originate?

The mammillary processes of the lumbar vertebrae.

9. From which vertebral processes does the thoracic multifidus originate?

The transverse processes of the thoracic vertebrae.

10. From which vertebral structures does the cervical multifidus originate?

The articular processes of the lower cervical vertebrae.

11. Where do the superiorly directed fascicles of the multifidus insert?

Onto the spinous processes of vertebrae above their origins.

12. How many vertebral levels do individual multifidus fascicles typically span?

Approximately two to four vertebral levels.

13. What is the general direction of multifidus muscle fascicles?

Superomedially from their inferior attachments toward the spinous processes above.

14. Which nerves innervate the multifidus muscle?

The medial branches of the posterior rami of spinal nerves.

15. What movement results from bilateral contraction of the multifidus?

Extension of the vertebral column.

16. What rotational movement can unilateral contraction of the multifidus produce?

Contralateral rotation of the vertebral column.

17. What is the principal stabilizing function of the multifidus?

Providing segmental stabilization and controlling movement between adjacent vertebrae.

18. How does the multifidus contribute to spinal stability during limb movements?

It helps resist unwanted intervertebral motion while forces are transmitted through the trunk.

19. Which deep back muscle lies immediately medial to the lumbar multifidus?

The lumbar interspinous muscles lie near its medial attachments.

20. Which fascial structure encloses the multifidus in the lumbar region?

The posterior layer of the thoracolumbar fascia and associated deep fascial attachments.

21. Which muscle group lies lateral to the multifidus in the lumbar region?

The erector spinae group, particularly the longissimus muscle.

22. What vascular sources supply the multifidus muscle?

Dorsal branches of regional segmental arteries, including lumbar, posterior intercostal, and cervical vessels.

23. What structural feature helps the multifidus provide precise intervertebral control?

Its short, overlapping fascicles attach across relatively few vertebral segments.

24. What muscular changes are commonly observed in the multifidus in patients with chronic low back pain?

Reduced muscle cross-sectional area and increased fatty infiltration, although findings vary.

25. How can injury to the medial branch of a lumbar posterior ramus affect the multifidus?

It may cause segmental multifidus denervation, weakness, and subsequent atrophy.