Lumbopelvic rhythm

Question 1

Lumbopelvic rhythm (LPR)

Answer 1

The kinematic relationship between the lumbar spine and hip joints during
sagittal plane movements

Attention to LPR and its impact on spinal extensor muscle activity and joint loading patterns may provide clues for detecting atypical muscle and
joint interactions and associated movement dysfunction within the region

Question 2

Lumbopelvic rhythm (LPR)Flexion

Answer 2

Typical strategy – lumbar flexion with simultaneous hip flexion

For most, lumbar flexion occurs slightly more during the first 25% of the bend, while hip flexion occurs slightly more during the last 25% of the bend

Observe for variations in lumbar and hip flexion (excessive or limited)

Question 3

Lumbopelvic rhythm (LPR)Extension

Answer 3

Typical strategy – three consecutive phases

Early phase – hip extension (pelvis on femurs)

Middle phase – shared activation of hip and lumbar extensors

Completion – muscle activity typically ceases once the LOG falls posterior to the hips

Benefits of posterior pelvic tilt first – decreases the EMA of the BW during the early phase to decrease demand on the lumbar extensors

Question 4

Intervertebral Discs

Answer 4

Outer fibrous layer
= Annulus fibrosus

Inner gel layer
= Nucleus pulposus

Question 5

Joint Forces

Answer 5

compression
tension
shear

Question 6

Compression

Answer 6

External and Internal loading
> Gravity, external weight
> Pull of muscles (active) and ligaments (passive)

Shared load between vertebral bodies and facet joints
> Up to 30% of load – facets

Dampened by intervertebral disks
> Compression loads will change with posture

Question 7

Tension

Answer 7

Joint separation pulls on discs

Usually occurs on opposite side of osteokinematic motion

Common cause of injury to disc
> Protrusion
> Prolapse
> Extrusion
> Sequestration

Question 8

Shear

Answer 8

Force at discs caused by sliding of vertebral bodies

Increased with compression forces, flexion, and extension

Resisted by facet joints

Increased with larger lordosis = Line of gravity shifts anteriorly

Question 9

Arthrokinematics of the Lumbar Spine

Answer 9

Axis of Rotation: L3 vertebral body

Flexion: inferior facet of L2 glides anteriorly and superiorly on the superior facet of L3 = Anterior disc compression

Extension: inferior facet of L2 glides posteriorly and inferiorly on the superior facet of L3 = Posterior disc compression