Lumbar Spine Examination
The lumbar spine examination must identify radiculopathy, exclude cauda equina syndrome, and differentiate between mechanical pain, disc herniation, and spinal stenosis. The straight leg raise is the key provocative test. Always ask about bladder function.
Quick Reference One-Pager
Look
- Posture and lordosis
- Scoliosis (sciatic list)
- Muscle wasting
- Gait pattern
- Skin changes
Feel
- Spinous processes (L1-S1)
- Paraspinal muscles
- SI joints
- Sciatic notch
Move
- Flexion (finger-floor distance)
- Extension
- Lateral flexion
- Schober's test
Special Tests
- Straight leg raise (L5, S1)
- Femoral stretch (L2, L3, L4)
- Crossed SLR
- Slump test
- Bowstring sign
Introduction and Setup
Before You Start
Patient Positioning:
- Standing for inspection and movements
- Supine for SLR and neurological examination
- Prone for femoral stretch and palpation
Exposure: Back exposed from neck to buttocks, lower limbs for neurological examination
Consent Script: "I'm going to examine your lower back. I'll start by watching you move, then examine you lying down. I'll need to test the strength and sensation in your legs. Please tell me if anything causes pain."
Key Anatomy:
- 5 lumbar vertebrae, sacrum, coccyx
- Lumbar nerve roots exit BELOW corresponding vertebra (L4 root exits at L4-5 level)
- Conus medullaris ends at L1-2, cauda equina below
- Common disc levels: L4-5 (L5 root), L5-S1 (S1 root)
Red Flags (Screen First)
CAUDA EQUINA SYNDROME - SURGICAL EMERGENCY:
- Bilateral leg symptoms: Pain, weakness, or numbness
- Saddle anesthesia: Numbness in perianal region, buttocks
- Bladder dysfunction: Retention, incontinence, poor stream
- Bowel dysfunction: Fecal incontinence
- Progressive neurological deficit: Especially bilateral
Other Red Flags:
- Age under 20 or over 55 with new symptoms
- Constant, non-mechanical pain (worse at night)
- Thoracic pain
- History of malignancy
- Constitutional symptoms (fever, weight loss)
- IV drug use
- Immunosuppression
- Structural deformity
- Bilateral symptoms or signs
Look (Inspection)
- Scoliosis: Structural vs antalgic (sciatic list)
- Muscle bulk: Paraspinal wasting, gluteal wasting
- Skin: Hairy patch, dimple (spina bifida), café au lait spots
- Alignment: Shoulders/pelvis level
- Scars: Previous surgery
Sciatic List (Antalgic Scoliosis): The patient leans away from the side of a lateral disc herniation to decompress the nerve root. This is a compensatory posture, not a structural scoliosis, and corrects when the disc pathology resolves.
Feel (Palpation)
Systematic Palpation Sequence
Posterior Midline:
- L1-L5 spinous processes: Step-off (spondylolisthesis), tenderness
- Sacrum: S1, S2
- Coccyx: Tenderness (coccydynia)
Posterior Lateral:
- Paraspinal muscles: Spasm, tenderness
- Quadratus lumborum: Deep lateral
- Iliac crest: Reference point, greater than 4cm below = L4
- PSIS: Posterior superior iliac spine
SI Joint Region:
- SI joint: Tenderness (sacroiliitis)
- Greater sciatic notch: Sciatic nerve (piriformis syndrome)
Landmarks:
- Iliac crests are level with L4 spinous process
- PSIS are level with S2
- Tuffier's line (intercristal line) for lumbar puncture at L4-5
Move (Range of Motion)
- normalRange
- 0-90°
- technique
- Touch toes keeping knees straight
- keyPoints
- Measure fingertip-floor distance; normal rhythm
- normalRange
- 0-30°
- technique
- Lean back with hands on hips
- keyPoints
- May reproduce stenosis symptoms
- normalRange
- 0-30° each side
- technique
- Slide hand down thigh
- keyPoints
- Compare sides, restricted in disc disease
- normalRange
- 0-45° each side
- technique
- Rotate shoulders with pelvis fixed
- keyPoints
- Primarily thoracolumbar junction
Special test
Schober's Test (Modified)
Measure lumbar spine flexion
Technique
- 1Mark a point at the level of the PSIS (approximately S2)
- 2Mark 10cm above and 5cm below
- 3Ask patient to flex forward
- 4Re-measure the distance between marks
Positive Sign
Less than 5cm increase (total should be greater than 20cm)
Indicates
Reduced lumbar flexion (ankylosing spondylitis, mechanical stiffness)
Diagnostic Accuracy
Ability to detect true positives
Ability to exclude false positives
Special Tests
Tension Signs (Nerve Root Stretch)
Special test
Straight Leg Raise (Lasègue's Test)
L5/S1 nerve root tension (sciatic nerve)
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Technique
- 1Patient supine, legs flat
- 2Lift affected leg by the heel with knee extended
- 3Note angle at which pain occurs
- 4Pain beyond 70° is not significant (hamstring)
Positive Sign
Reproduction of radicular leg pain (not just back pain or hamstring tightness) between 30° and 70°
Indicates
Lower lumbar radiculopathy (L4-5 or L5-S1 disc)
Diagnostic Accuracy
Ability to detect true positives
Ability to exclude false positives
Special test
Bowstring Sign (Popliteal Compression Test)
Confirm positive SLR is neural
Technique
- 1Raise leg until pain is reproduced (positive SLR)
- 2Lower slightly to reduce pain
- 3Apply pressure to popliteal fossa (compress tibial nerve)
Positive Sign
Reproduction of radicular symptoms with popliteal pressure
Indicates
Confirms neural origin of positive SLR (not hamstring)
Diagnostic Accuracy
Ability to detect true positives
Ability to exclude false positives
Special test
Crossed Straight Leg Raise (Contralateral)
Confirm disc herniation
Technique
- 1Perform SLR on the unaffected (asymptomatic) leg
Positive Sign
Reproduction of pain in the affected leg
Indicates
Central or large lateral disc herniation (highly specific)
Diagnostic Accuracy
Ability to detect true positives
Ability to exclude false positives
Special test
Slump Test
Dural tension (combines spinal flexion with SLR)
Technique
- 1Patient seated, slump forward (flex thoracolumbar spine)
- 2Flex neck (chin to chest)
- 3Extend knee of affected leg
- 4Dorsiflex ankle
Positive Sign
Reproduction of radicular symptoms
Indicates
Dural tension, lumbar radiculopathy (more sensitive than SLR)
Diagnostic Accuracy
Ability to detect true positives
Ability to exclude false positives
Special test
Femoral Stretch Test (Reverse Lasègue's)
Upper lumbar radiculopathy (L2, L3, L4)
Technique
- 1Patient prone
- 2Flex the knee to 90°
- 3Extend the hip (lift thigh off bed)
Positive Sign
Reproduction of anterior thigh pain (femoral nerve distribution)
Indicates
Upper lumbar radiculopathy (L2-4), femoral nerve tension
Diagnostic Accuracy
Ability to detect true positives
Ability to exclude false positives
Other Tests
Special test
Flip Test (Sitting SLR)
Consistency of findings (malingering screen)
Technique
- 1Patient seated
- 2Examine knee reflex as pretense
- 3Extend knee fully (effectively performing SLR in sitting)
Positive Sign
Patient leans back or complains of leg pain at same angle as supine SLR
Indicates
Consistent findings (if no pain when patient was distracted, consider non-organic cause)
Diagnostic Accuracy
Ability to detect true positives
Ability to exclude false positives
Special test
Prone Instability Test
Lumbar segmental instability
Technique
- 1Patient prone with legs hanging off end of bed
- 2Apply PA pressure to each lumbar segment - note pain
- 3Patient lifts legs off floor (activates paraspinal muscles)
- 4Repeat PA pressure
Positive Sign
Pain with PA pressure that is relieved when muscles activated
Indicates
Segmental instability (stabilization exercises may help)
Diagnostic Accuracy
Ability to detect true positives
Ability to exclude false positives
Neurological Assessment
Motor Testing - Myotomes
- Muscle
- Iliopsoas
- Action
- Hip flexion
- Test
- Resisted hip flexion
- Muscle
- Quadriceps
- Action
- Knee extension
- Test
- Resisted knee extension
- Muscle
- Tibialis anterior
- Action
- Ankle dorsiflexion
- Test
- Heel walking
- Muscle
- EHL, Gluteus medius
- Action
- Great toe extension, Hip abduction
- Test
- Toe extension, Trendelenburg
- Muscle
- Gastrocnemius, Peronei
- Action
- Ankle plantarflexion, Eversion
- Test
- Toe walking
- Muscle
- Hamstrings
- Action
- Knee flexion
- Test
- Resisted knee flexion
Sensory Testing - Dermatomes
- Area
- Anterior thigh
- Area
- Medial thigh above knee
- Area
- Medial leg and foot (medial malleolus)
- Area
- Lateral leg, dorsum of foot, great toe
- Area
- Lateral foot, sole, lateral malleolus
- Area
- Posterior thigh
- Area
- Perianal (saddle area) - ALWAYS CHECK
Reflex Testing
- Root
- L3,4
- Technique
- Tap patellar tendon
- Root
- S1
- Technique
- Tap Achilles tendon
- Root
- UMN
- Technique
- Plantar surface stroke
- Root
- S2-4
- Technique
- Perianal scratch (CES screening)
- Root
- S2-4
- Technique
- Squeeze glans, feel anal contraction
L5 vs S1 Radiculopathy - Key Differentiators:
- L5 Root
- Lateral leg, dorsum foot
- S1 Root
- Posterior calf, lateral foot, sole
- L5 Root
- EHL, ankle dorsiflexion, hip abduction
- S1 Root
- Plantarflexion, eversion
- L5 Root
- Dorsum foot, great toe
- S1 Root
- Lateral foot, sole
- L5 Root
- None (or slightly reduced ankle jerk)
- S1 Root
- Ankle jerk diminished/absent
- L5 Root
- L4-5
- S1 Root
- L5-S1
Vascular Assessment
Lower Limb Pulses
- Femoral: Groin, below inguinal ligament
- Popliteal: Posterior knee (deep)
- Dorsalis pedis: Dorsum of foot
- Posterior tibial: Behind medial malleolus
Claudication History:
- Vascular: Cramping in calf, relieved by rest in any position
- Neurogenic: Aching/burning in thighs and legs, relieved by flexion (sitting, leaning forward)
Complete the Examination
Always state to the examiner:
"To complete my examination, I would like to:
- Examine the hips to exclude referred pain
- Examine the SI joints if indicated
- Check peripheral pulses (vascular claudication)
- Perform rectal examination if cauda equina suspected
- Obtain X-rays (AP, lateral) and MRI if indicated"
Summary Presentation
“35-year-old man with 3-week history of low back pain radiating to the left leg and foot.”
Common Conditions Table
- look
- Sciatic list, reduced flexion
- feel
- Paraspinal spasm
- move
- Limited flexion
- specialTests
- SLR +, dermatomal signs, weakness
- look
- May be normal, stooped
- feel
- May be normal
- move
- Extension limited/painful
- specialTests
- Neurogenic claudication, bicycle test
- look
- Loss of lordosis
- feel
- Paraspinal tenderness
- move
- All directions limited
- specialTests
- No neurological deficit, no tension signs
- look
- Step-off palpable, hyperlordosis
- feel
- Step-off at L4 or L5
- move
- Extension painful
- specialTests
- May have radiculopathy
- look
- May be normal
- feel
- Normal
- move
- May be normal
- specialTests
- Saddle anesthesia, bladder dysfunction, bilateral signs
Waddell's Signs (Non-Organic Back Pain)
Five Categories
- Tenderness: Superficial, non-anatomical (whole back)
- Simulation: Pain on axial loading or rotation without spinal movement
- Distraction: Discrepancy between sitting and supine SLR (Flip test)
- Regional disturbance: Non-dermatomal sensory/motor changes
- Overreaction: Disproportionate verbal or physical response
Interpretation:
- 3 or more positive categories suggest non-organic component
- Does NOT mean the patient is malingering - may indicate distress
- Consider psychological assessment
Examiner Tips
Do
- Screen for cauda equina syndrome
- Perform SLR correctly (30-70° range significant)
- Use Bowstring sign to confirm neural origin
- Differentiate L5 from S1 radiculopathy precisely
- Examine the hips
Don't
- Accept back pain as positive SLR (must be leg pain)
- Forget perianal sensation
- Confuse neurogenic with vascular claudication
- Miss femoral stretch test for upper lumbar roots
- Forget to check for Waddell's signs in atypical presentations