Classification
- Type: Synovial plane (gliding)
- Degrees of freedom: 6 (3 rotations + 3 translations; flexion/extension is the dominant movement)
- Region: Lumbar spine (L1-L2 through L5-S1)
Articular Surfaces
- Superior articular facets (concave): Face posteromedially. The sagittal orientation means the facets interlock like book pages — the inferior facet of the vertebra above nests between the superior facets of the vertebra below. This interlocking provides strong resistance to anterior shear and rotation.
- Inferior articular facets (convex): Face anterolaterally. They project downward and laterally from the lamina.
- Tropism: Asymmetric facet orientation (one facet more sagittal, the other more coronal) is present in approximately 20% of the population. Tropism predisposes to rotational injury and disc degeneration at that segment because the more coronally oriented facet permits rotation that the disc cannot tolerate.
Movements and ROM
Why lumbar rotation is minimal. The sagittal facet orientation means that during rotation, the inferior articular process of the vertebra above immediately contacts the superior articular process of the vertebra below — the facets physically block further rotation after only 1–2° per segment. This protects the disc from rotational shear, which it tolerates poorly. Activities requiring trunk rotation (golf, tennis) primarily use thoracic rotation, not lumbar.
Capsular Pattern
Lateral flexion > Rotation > Extension (some flexion limitation)
The lumbar capsular pattern is debated. Most sources describe lateral flexion and rotation as the most limited movements, with extension also restricted. Flexion is the least affected. The pattern helps distinguish capsular (facet) pathology from discogenic pain (which typically produces flexion-dominant limitation).
Resting Position
- Midway between flexion and extension (neutral lordosis)
- Facets partially separated, capsules relaxed
Close-Packed Position
- Full extension
- Maximum facet compression, capsules taut, posterior elements maximally loaded
- Extension is provocative in facet joint conditions because it compresses the already-irritated facets
End-Feels
| Movement |
Normal End-Feel |
Type |
| Flexion |
Capsular (firm) |
Posterior capsule, ligamentum flavum, interspinous ligament, supraspinous ligament, posterior annulus |
| Extension |
Bony / capsular |
Facet compression (bony feel); spinous process contact at extreme extension |
| Lateral flexion |
Capsular (firm) |
Contralateral capsule, intertransverse ligaments, contralateral quadratus lumborum |
| Rotation |
Bony (hard) |
Facet contact — the sagittal facets physically block rotation after 1–2° |
Ligaments
The lumbar facets share the standard spinal ligamentous system:
- Ligamentum flavum — highest elastin content of any ligament; resists flexion; hypertrophy contributes to lumbar spinal stenosis
- Interspinous ligament — between spinous processes; resists flexion
- Supraspinous ligament — along spinous process tips; resists flexion; ends at L4 or L5 (does not extend to S1 in many individuals)
- Iliolumbar ligament — L4 and L5 transverse processes → iliac crest; stabilizes L4-L5 and L5-S1 against excessive lateral flexion and rotation; frequently strained in acute low back injury
- Facet capsular ligaments — innervated by medial branches of the lumbar dorsal rami; the primary source of facet-mediated low back pain
Mobilization Techniques
Hands-on instruction is required. The descriptions below provide clinical reference detail for understanding and supervised practice. They are not a substitute for instructor-led technique training. Correct hand placement, force dosage, and tissue response interpretation require hands-on coaching and feedback.
General Contraindications
- Absolute: Cauda equina syndrome (bilateral lower extremity neurological deficit, bowel/bladder dysfunction, saddle anesthesia — medical emergency), fracture, spondylolisthesis with neurological deficit, spinal malignancy, active infection, severe spinal stenosis with neurological signs
- Relative: Spondylolisthesis without neurological deficit (Grade I–II only, avoid extension-biased techniques), significant osteoporosis, acute disc herniation with radiculopathy (avoid provocation — use distraction-based techniques), pregnancy (modified positioning)
Unilateral PA Glide on the Lumbar Articular Pillar
Purpose: Restores segmental mobility at a specific lumbar level. Produces coupled lateral flexion and rotation at the target segment. The most common lumbar facet mobilization technique.
Patient position:
- Prone on the treatment table
- A pillow under the abdomen to flatten the lumbar lordosis (reduces facet compression and makes the facets more accessible)
Hand placement:
- Mobilizing hand: Pisiform or thumb pad contacts the mamillary process (the posterior palpable prominence of the superior articular process) or the transverse process at the target level, on the restricted side. In the lumbar spine, the transverse processes are palpable approximately 3–4 cm lateral to the midline.
- Reinforcing hand: Overlapping hands or interlocked fingers to transmit sufficient force (the lumbar spine requires more force than cervical or thoracic due to the large muscle mass and ligamentous bulk).
Technique execution:
- Apply an oscillatory force directed anteriorly (toward the table)
- The force can be angled cephalad or caudad to bias different motion components
- Grade I–II: Pain modulation for acute lumbar facet flare, muscle spasm, or when the segment is irritable
- Grade III–IV: Large to small amplitude oscillations into end-range segmental resistance for chronic stiffness, post-immobilization restriction, or degenerative hypomobility
- Rhythm: 1–2 oscillations per second
- Duration: 30–60 seconds per segment, 2–3 sets
Indications:
- Decreased segmental mobility on PA testing (compare adjacent segments and contralateral side)
- Unilateral low back pain with facet tenderness
- Extension-aggravated low back pain (facet compression)
- Lumbar stiffness contributing to compensatory thoracic or hip restriction
Technique notes:
- Segmental identification: Locate L4 spinous process at the level of the iliac crests (Tuffier's line). Count up or down from L4. The transverse processes are lateral to the spinous processes at the same segmental level (lumbar spinous processes project straight posteriorly, unlike the angled thoracic processes).
- Common error: Applying force to the erector spinae muscle belly rather than the bony transverse process. Press firmly enough to palpate through the muscle.
- Prone vs. side-lying: Prone PA glides are simpler but compress the facets. For patients with extension-sensitive pain, side-lying lumbar rotation mobilization (see below) may be more comfortable.
- Integration: Perform after erector spinae, multifidus, and quadratus lumborum release.
Lumbar Rotation Mobilization (Side-Lying)
Purpose: Restores lumbar rotation and lateral flexion. This technique gaps the facet joints on the upper side, stretching the capsule and restoring mobility. It is often better tolerated than prone PA glides in extension-sensitive patients because the side-lying position reduces facet compression.
Patient position:
- Side-lying with the restricted side up
- Bottom leg straight, top leg flexed to approximately 60° hip and knee flexion (foot resting behind the bottom knee)
- The clinician flexes or extends the lumbar spine to the target segment by adjusting the patient's upper body position until the motion is felt at the palpated segment
Hand placement:
- Stabilizing hand: Placed on the patient's pelvis (iliac crest or ASIS), controlling the lower body
- Mobilizing hand: Placed on the patient's upper shoulder or thorax, controlling the upper body
- Palpating hand (during setup): The clinician palpates the interspinous space at the target level to localize motion
Technique execution:
- With the pelvis stabilized, apply a rotational oscillatory force through the thorax — rotating the upper body toward the table (posterior rotation of the upper trunk)
- The rotation is localized to the target segment by the leg positioning and trunk flexion/extension setup
- Grade I–II: Gentle oscillations for pain modulation
- Grade III–IV: Oscillations into the end-range rotational resistance at the target segment
- Duration: 30–60 seconds, 2–3 sets
Indications:
- Lumbar rotation restriction with capsular end-feel
- Extension-sensitive facet pain (side-lying position is more comfortable)
- Post-surgical stiffness (when surgeon has cleared for mobilization)
- Combined facet and disc restriction (the rotation component gaps the facet while the flexion component opens the posterior disc space)
Technique notes:
- Localization is the key skill. The technique is only effective if the rotation is localized to the target segment. This requires careful pre-positioning (flexion/extension to the segment) and palpation during the technique.
- Common error: Rotating through multiple segments instead of localizing to one level. If multiple segments are moving, adjust the pre-positioning.
- Reassessment: Re-test lumbar rotation and lateral flexion. Reassess PA glide compliance at the target segment.
Muscles Crossing These Joints
Deep Stabilizers
- anatomy/muscles/multifidus — the most important lumbar segmental stabilizer; atrophies rapidly and specifically after lumbar injury; does not spontaneously recover — requires targeted retraining
- anatomy/muscles/transversus-abdominis — the deepest abdominal muscle; co-contracts with multifidus to stabilize the lumbar spine; delayed activation in patients with chronic low back pain
Erector Spinae Group
- anatomy/muscles/iliocostalis-lumborum — lateral column; extension and lateral flexion
- anatomy/muscles/longissimus-thoracis — intermediate column; extension
Other
Conditions Affecting These Joints
- Lumbar facet syndrome — the most common source of mechanical low back pain alongside disc pathology; unilateral, extension-aggravated pain with facet tenderness; referred pain to the buttock and proximal thigh (does not typically radiate below the knee — unlike radiculopathy)
- conditions/osteoarthritis — lumbar facet OA is nearly universal with aging; contributes to spinal stenosis via facet hypertrophy and osteophyte formation
- Spondylolisthesis — anterior slippage of one vertebra on another; most common at L5-S1 and L4-L5; may be isthmic (pars interarticularis defect) or degenerative (facet and disc degeneration)
- Lumbar spinal stenosis — narrowing of the spinal canal from facet hypertrophy, ligamentum flavum hypertrophy, and disc bulge; produces neurogenic claudication (leg pain and weakness with walking, relieved by flexion)
- conditions/lumbar-disc-herniation — disc pathology and facet pathology frequently coexist; the disc and facet form the "three-joint complex" at each segment
Clinical Notes
- The "three-joint complex." Each lumbar segment has three joints: the intervertebral disc anteriorly and two facet joints posteriorly. They are mechanically interdependent — disc degeneration increases facet loading (and vice versa). Treating facets without addressing disc health (or vice versa) is incomplete.
- Facet pain vs. discogenic pain. Facet pain is typically worse with extension (facet compression) and relieved by flexion. Discogenic pain is typically worse with flexion (increases intradiscal pressure) and relieved by extension. This extension/flexion preference is the primary clinical distinction and guides treatment approach.
- Lumbar multifidus atrophy. After lumbar injury or pain, the multifidus at the affected segment atrophies rapidly (within 24–72 hours) and specifically — visible as fatty infiltration on MRI. Unlike other muscles, segmental multifidus does not spontaneously recover with general exercise. Specific retraining (isometric multifidus contractions in neutral spine) is required. Mobilization restores joint mobility; multifidus retraining restores stability.
- Facet tropism and disc injury. Asymmetric facet orientation (tropism) allows more rotation on one side than the other, subjecting the disc to asymmetric rotational stress. Segments with significant tropism have higher rates of disc herniation. This is a structural predisposition that cannot be modified.
Key Takeaways
- Lumbar facets are oriented in the sagittal plane (~90°) — they permit flexion/extension and physically block rotation to ~1–2° per segment, protecting the disc from rotational shear.
- Facet pain is extension-aggravated; discogenic pain is flexion-aggravated — this distinction guides treatment approach.
- The three-joint complex (disc + two facets) is mechanically interdependent — treat both components for lasting results.
- Segmental multifidus atrophy occurs within 24–72 hours of lumbar injury and does not self-recover — specific retraining is required alongside mobilization.
