Low Back Pain: Focused Exam

For the Primary Care clinician

Low Back Pain • Common complaint in primary care, yet: – Often difficult complaint to address when dealing with a complicated patient – Providers may be unsure of exam – Seen as chronic problem that does not improve, and may be concerned about medication- or disability-seeking patients

Today’s talk • Focus on practical information to help the practitioner know: • what questions to ask, • what exam to perform, • what studies to order.

Today’s talk • Anatomy review • Pain generators of the back • Exam to rule out emergent issues • Exam for radiculopathy • Exam to discover cause of patient’s pain • Appropriate ordering of studies

Anatomy review • 7 Cervical vertebrae • 12 Thoracic vertebrae • 5 Lumbar vertebrae • Sacrum (5 fused) • Coccyx (4 fused) • Focus today on lumbar/sacral spine

Anatomy review • Vertebra • Intervertebral discs • Facet joints • Spinal nerve • Epidural space

Anatomy review

Pain generators • Disc rupture • Nerve impingement • Joints-facets or SI • Myofascial

Emergent causes of back pain • Cancer – Ask: 1) history of cancer; 2) pain which wakes patient from sleep, 3) weight loss, 4) new onset of pain in an elderly patient, • Cauda equina – Ask: 1) bowel or bladder problems such as retention, incontinence, decreased sensation; 2) saddle numbness.

• Infection – Ask: 1) fevers, 2) history of epidurals or IVDU

Examination for Radicular pain • Mostly caused by intervertebral disc problems such as herniation, degenerative disc disease, or narrowing from degenerative joint disease.

• Looking for a pattern of neurologic deficits: for example, that L5 strength, reflexes and sensation are all affected.

Examination for Radicular pain • Neurologic exam: – Strength – Reflexes – Sensation • Provocative tests: – Straight leg raise (SLR), contralateral SLR, Slump test

Strength testing • Explain to patient that you are testing her strength and would like her to push as hard as possible; difference between true weakness and pain-inhibited weakness.

• In general, you should not be able to “break” the person’s strength; if you can, there may be weakness. Test against strength of non-affected side, if possible.

Neuro Exam-Strength • Hip Flexor Strength Testing – L1,2,3

Neuro Exam-Strength • Knee Extension – L2-4 – Buttock should rise from table

Neuro Exam-Strength • Dorsiflexion – L4,5

Neuro Exam-Strength • Extensor Hallucis Longus (EHL) – Big toe dorsiflexion – L5

Neuro Exam • Plantar Flexion – One-legged x 3 = 5/5 strength – S1

Neuro Exam-reflexes • Patella Reflex – L4

Neuro Exam-reflexes • Medial Hamstring Reflex – L5

Neuro Exam-reflexes • Achilles Reflex – S1

Neuro Exam-Sensation • Pinprick Sensation Testing – L2

Neuro Exam-Sensation • Pinprick Sensation Testing – L3

Neuro Exam-Sensation • Pinprick Sensation Testing – L4

Neuro Exam-Sensation • Pinprick Sensation Testing – L5

Neuro Exam-Sensation • Pinprick Sensation Testing – S1

Neuro Exam-Sensation • Pinprick Sensation Testing – S2

Provocative testing • SLR • cSLR • 30-70 degrees

Radicular Pain • If your neurologic exam shows concern for acute neurologic changes in a nerve root pattern, consider MRI and referral to orthopedic surgeons.

• If you are unclear about the cause of neurologic changes, such as radiculopathy versus diabetic neuropathy, consider referral for EMG.

Disc disease • May see disc space narrowing on plain films.

• May see disc extrusion, bulges on MRI

Degenerative joint disease • Facet joints, or sacroiliac joint may be affected • You may see facet degeneration, spurring, and/or osteophyte formation on radiographic studies.

• Combined Extension & Rotation – Reproduction of Pain

Myofascial pain • May see muscle spasm, tense, tight muscles.

• Patient may get relief from NSAIDs, acetaminophen, topical preparations, stretching, trigger point injection.

• May be a component of pain, no matter the root cause of pain.

Exam

• Alignment • Weight Bearing Joints • If unable to determine free standing – try having patient stand against a wall

• Offset • Rotation – hand position – shoulder position

• Weight Balance

• Shoulder Height – symmetric Exam

• Iliac Crest Height – symmetric Exam

• Adam’s Forward Bending Test – Scoliosis • Fingertip to Floor – ROM • Reproduction of Pain

• Extension – ROM • Reproduction of Pain

Waddell test • Tests of malingering • Each test counts as +1 if +, 0 if – Superficial skin tenderness to light pinch over wide area of lumbar spine – Deep tenderness over wide area, often extending to thoracic spine, sacrum, and/or pelvis.

– Low back pain on axial loading of spine in standing – SLR test positive supine, but not when seated with knee extended to test babinski reflex.

– Abnormal or inconsistent neurological (motor and/or sensory) patterns.

– Overreaction.

– If 3+ points or more, investigate for non-organic cause.

Waddell, GJ et al. Nonorganic physical signs in low back pain. Spine. 5:117-25, 1980.