Advanced Multifidus Quiz

Q1. Which posterior sacral and pelvic structures contribute to the extensive inferior attachment of lumbar multifidus?

• Obturator membrane
• Anterior sacral foramina only
• Posterior sacrum and adjacent posterior sacroiliac region
• Pubic crest and inguinal ligament

Q2. How does the vertebral span of multifidus distinguish it from semispinalis and rotatores?

• It spans only one segment in every region
• It is always the longest transversospinalis muscle
• It has an intermediate vertebral span within transversospinalis
• It has no segmental organization

Q3. Why does unilateral multifidus contribute to contralateral vertebral rotation?

• It acts through the rectus sheath
• Its oblique pull on spinous processes produces rotation toward the opposite side
• It crosses the hip joint
• Its fibers attach only to ribs

Q4. Why is multifidus especially important for lumbar segmental stability rather than simply producing large spinal movements?

• It acts primarily on the upper limb
• Short deep fascicles provide local control across limited motion segments
• It is the largest superficial back muscle
• It has no attachment to lumbar vertebrae

Q5. What is the relationship of lumbar multifidus to the spinous processes?

• It never attaches to spinous processes
• It lies entirely anterior to vertebral bodies
• It passes through the vertebral canal
• Its fascicles converge on spinous processes from deeper inferolateral attachments

Q6. How does segmental posterior ramus innervation relate to multifidus anatomy?

• Its innervation arises from the brachial plexus
• Its segmental nerve supply complements its local segmental architecture
• Only anterior rami supply intrinsic back muscles
• A single cranial nerve supplies the entire muscle

Q7. Why can multifidus atrophy be relevant to lumbar spine function?

• Reduced multifidus function can impair local segmental control
• It affects only shoulder motion
• It directly causes vertebral fractures in every case
• It eliminates all spinal movement permanently

Q8. Which anatomical feature allows multifidus fascicles to generate extension while also controlling rotation?

• Insertion exclusively on ribs
• An anterior vertical course along vertebral bodies
• A tendon passing through the hip joint
• Posterior position combined with an oblique superomedial fiber course

Q9. Why is multifidus classified as an epaxial muscle?

• It is an anterior abdominal wall muscle
• It is derived from foregut smooth muscle
• It develops as a limb muscle supplied by anterior rami
• It is intrinsic dorsal musculature innervated by posterior rami

Q10. Which statement best integrates the anatomy and function of multifidus?

• It is a long erector spinae column supplied by anterior rami
• It is a superficial extrinsic muscle acting mainly on the scapula
• It is a deep segmental transversospinalis muscle specialized for vertebral control, extension, and contralateral rotation
• It is a thoracic wall muscle whose main action is forced expiration