Lumbar Biomechanics

Question 1

What is an articular facet tends to move closer to its partner facet usually caused by compression force

Answer 1

Approximation of joint surfaces

Question 2

What is articular facet surface tends to move away from its partner facet usually caused by distraction force

Answer 2

Seperation (gapping) between joint surfaces

Question 3

What is articular facet translates to linear or curvilinear direction relative to another articular facet usually caused by a force directed trangential to the joint surfaces

Answer 3

Sliding (gliding) between joint surfaces

Question 4

When the lumbar flexes what happens to the superior vertebra?

Answer 4

Anterior rotation, in transverse axis
translates anteriorly in the sagittal axis

Question 5

When lumbar flexes what happens anteriorly?

Answer 5

compresses anterior disc (annulus)
anterior longitudinal ligament has laxity

Question 6

When lumbar flexes what happens posteriorly?

Answer 6

Inferior articular process of superior vertebrae moves superiorly on superior articular process of inferior vertebra
opening of facet joints
seperation of spinous processes

Question 7

When lumbar extends what happens to superior vertebrae?

Answer 7

• rotates posteriorly on transverse axis
• translates posteriorly on sagittal axis

Question 8

When lumbar extends what happens anteriorly?

Answer 8

• tension in anterior disc and musculature
• anterior longitduinal ligament becomes taut

Question 9

When lumbar extends what happens posteriorly?

Answer 9

• inferior articular process of superior vertebra moves inferior on the superior process of inferior vertebra
• ‘closing’ of facets , narrowing foramen
• posterior ligaments become lax

Question 10

When lumbar rotates what happens to the superior vertebra?

Answer 10

• rotates around vertical axis
• translation depends on level of involved segment

Question 11

When lumbar goes into lateral flexion what happens to superior vertebra?

Answer 11

• rotates around AP axis
• tranlates laterally along horiztonal axis

Question 12

When in lateral flexion where is the tension?

Answer 12

Side of convexity (contralaterally)

Question 13

When in lateral flexion where is the Laxity?

Answer 13

side of concavity (ipsilteral)

Question 14

What is kinematic relationship bewteen the lumbar spine and hip joints during sagittal plane movement

Answer 14

Lumbopelvic rhythm