Unit 5 - Lumbar Spine Applied Biomechanics

Question 1

Characteristics of Flexion

Answer 1

• Forward bending
• Anterior motion of superior vertebrae on inferior vertebrae -> facet joints “open up”
• Pressure on anterior surface of IVD
• Forced nucleus posterior

Question 2

Characteristics of Extension

Answer 2

• Backward bending
• Posterior motion of superior vertebrae on inferior vertebrae -> facet joints compress
• Pressure on posterior surface of IVD
• Forces nucleus anterior

Question 3

Characteristics of Sidebending

Answer 3

• Lateral flexion/side-bending
• Facets joints approximate “close down” on sideglide side (SG on right facets close on right)
• Facet joints gap “open up” on opposite side (SG right, facets gap on left)

Question 4

Characteristics of Rotation

Answer 4

• Occurs primarily in Thoracic spine (little/no rotation in Lumbar spine)
• In Lumbar spine, facet joints gap on rotation side (rotation right, facets gap on right)
• Facet joints approximate on opposite side (rotation right, facets approximate on left)