Back Pain Back Pain Anatomy and Biomechanics 1 — Questions and Answers
Question 1: Which spinal region is most commonly affected by back pain in the US adult population?
- Cervical
- Thoracic
- Lumbar (Correct answer)
- Sacral
Correct answer: Lumbar
The lumbar region bears the most mechanical load and is the most frequent site of back pain in adults.
Question 2: What structure acts as a shock absorber between vertebral bodies?
- Ligamentum flavum
- Intervertebral disc (Correct answer)
- Facet joint
- Spinous process
Correct answer: Intervertebral disc
Intervertebral discs contain a nucleus pulposus and annulus fibrosus that absorb compressive forces between vertebrae.
Question 3: Which muscle group is considered the primary stabilizer of the lumbar spine?
- Hamstrings
- Gluteus maximus
- Transversus abdominis (Correct answer)
- Rectus femoris
Correct answer: Transversus abdominis
The transversus abdominis acts as a natural corset and is the deepest core muscle providing lumbar stabilization.
Question 4: The nucleus pulposus of an intervertebral disc is primarily composed of which substance?
- Collagen type I
- Elastin
- Proteoglycans and water (Correct answer)
- Hyaluronic acid only
Correct answer: Proteoglycans and water
The nucleus pulposus is a hydrophilic gel consisting mainly of proteoglycans (aggrecan) and water, giving it its shock-absorbing properties.
Question 5: Which spinal nerve roots are typically compressed in an L4-L5 disc herniation causing sciatica?
- L2-L3
- L3-L4
- L4 or L5 (Correct answer)
- S2-S3
Correct answer: L4 or L5
An L4-L5 disc herniation most commonly compresses the L5 nerve root (posterolateral) or L4 root (far lateral).
Question 6: What is the term for the forward slipping of one vertebra over the one below it?
- Scoliosis
- Kyphosis
- Spondylolisthesis (Correct answer)
- Spondylolysis
Correct answer: Spondylolisthesis
Spondylolisthesis refers to anterior displacement of a vertebra relative to the vertebra below, commonly at L4-L5 or L5-S1.
Back Pain Back Pain Anatomy and Biomechanics 1
Which spinal region is most commonly affected by back pain in the US adult population?