Topic Overview

Frequently Asked Questions – Back

Surface Landmarks & Vertebrae

Q1. Which vertebra is called vertebra prominens?
→ C7.

Q2. Which vertebra corresponds to the spine of scapula?
→ T3.

Q3. Which vertebra corresponds to the inferior angle of scapula?
→ T7.

Q4. What is the vertebral level of highest point of iliac crest?
→ L4.

Q5. What vertebral level corresponds to PSIS dimples?
→ S2.

Q6. Which surface landmark corresponds to sacral hiatus?
→ Depression below sacral cornua at lower end of sacrum.

Skin & Fascia

Q7. Cutaneous innervation of back skin is by which nerves?
→ Dorsal rami of spinal nerves.

Q8. Why is skin of back prone to acne and sebaceous cysts?
→ Rich in sebaceous glands.

Q9. What is thoracolumbar fascia?
→ Strong fascia in lumbar region with posterior, middle, anterior layers.

Q10. Function of thoracolumbar fascia?
→ Provides attachment to latissimus dorsi, transversus abdominis, internal oblique; transmits mechanical stresses.

Muscles – Extrinsic

Q11. Which nerve supplies trapezius?
→ Spinal accessory nerve (motor) + C3, C4 (sensory).

Q12. Function of trapezius?
→ Elevates, retracts, depresses scapula; rotates scapula upward.

Q13. Which nerve supplies latissimus dorsi?
→ Thoracodorsal nerve.

Q14. Function of latissimus dorsi?
→ Extends, adducts, medially rotates arm; climbing muscle.

Q15. Which nerve supplies levator scapulae and rhomboids?
→ Dorsal scapular nerve.

Q16. Function of rhomboids?
→ Retract and stabilize scapula.

Muscles – Intrinsic

Q17. Which muscles form erector spinae group?
→ Iliocostalis, longissimus, spinalis.

Q18. Which muscles form transversospinalis group?
→ Semispinalis, multifidus, rotatores.

Q19. Nerve supply of intrinsic back muscles?
→ Dorsal rami of spinal nerves.

Q20. Function of erector spinae?
→ Main extensors of vertebral column.

Clinical Anatomy

Q21. Which nerve injury causes shoulder droop?
→ Spinal accessory nerve (trapezius paralysis).

Q22. Which nerve injury causes difficulty in climbing/rowing?
→ Thoracodorsal nerve (latissimus dorsi paralysis).

Q23. Which nerve injury weakens scapular retraction?
→ Dorsal scapular nerve (rhomboid weakness).

Q24. What is lumbago?
→ Pain due to strain of erector spinae.

Q25. What is Pott’s spine?
→ Tuberculosis of vertebrae producing kyphosis.

Q26. What is scoliosis?
→ Lateral curvature of spine with rotation.

Q27. Why is inferior angle of scapula an important landmark?
→ Indicates level of T7 vertebra.

Q28. What vertebral level is used for lumbar puncture?
→ L3–L4 or L4–L5 interspace (below spinal cord termination).

Q29. Which condition produces vesicular rash along dermatomes of back?
→ Herpes zoster (shingles).

Q30. Why is latissimus dorsi important in surgery?
→ Used in muscle flap/graft for breast reconstruction.