Low Back Pain

Low Back Pain: Initial Evaluation and Management

Objectives

The student will be able to perform and document an initial back exam, initiate conservative management for low back pain, and recognize when emergent consultations are required.

Background Information

An old problem - Egyptian records dating back 5,000 years.

Incidence - 60%-80% of the adult population.

Economic impact - Estimated to cost Americans 15 billion per year.

Etiology

Musculoskeletal system (most common) -- mechanical origin.

Intervertebral discs --degeneration or herniation (HNP).
Posterior apophyseal joints (Facet joints).
Muscle -- myofacial syndromes, spasm
Nerve compression or traction.

Referred pain from other systems --GI, GU, CV.

Infection, neoplasm, or inflammation.

History

Thorough history can help determine the etiology.

History to determine the type of mechanical etiology should include the onset of pain, pattern of previous episodes of pain, and limitation of activity caused by pain.
Ask about trauma or heavy lifting.
Ask about bowel and bladder control.
Seek evidence to suggest systemic conditions.
Seek evidence of infection or tumor.

History of previous treatment can guide effective therapy.

Include social history and consider secondary gain.

Physical Exam

Patient standing and disrobed.

Scoliosis.
Range of motion -- note location of pain.
Motor exam -- toe walking and heel walking.
Palpation for spasm.

Patient sitting.

Deep tendon reflexes -- knees and ankles.
Straight leg raises (SLR).
Sensory exam -- light touch, sharp and dull over dorsum of feet.
Motor exam.

Patient supine.

Straight leg raises (Figure 1).
Hip exam.
Abdominal exam.
Motor exam (Hoover Test - see below).

Patient prone or side position.

Motor exam of abductor muscles of hip.
Sensory exam of saddle area.
Rectal exam.

Figure 1. Straight Leg (SLR)

Ask the patient to localize the pain by pointing.
At the point the patient feels pain, lower the leg and dorsiflex the foot to

A positive SLR is present when the patient experiences both back pain

A positive SLR at lower degrees of elecation is correlated with a higher

A positive crossover SLR (pain in the affected leg when unaffected

Hoover Test

The Hoover test is performed during the straight leg test: As the patient tries to

Initial Studies

Lumbosacral spine x-rays (two views usually adequate):

Not indicated for most patients unless the pain has been present for two months.
Should be obtained early if tumor or infection is suspected.
Obtain during the first month of pain if patient is less than 20 or greater than 50 years of age.
Obtain acutely in cases of trauma.

Laboratory studies: Urinalysis, CBC, SMA --obtain as indicated to rule out systemic illness.

MRI or CT: Not usually indicated as part of initial work- up. Exceptions are included in "Reasons for Immediate Referral."

Findings that suggest patient is exaggerating symptoms:

Negative sitting LSR with positive supine SLR.
Positive Hoover Test (Figure 2).
Jerky or quick release on motor testing.
Back pain with rotation of hips on ROM testing.

Initial Management

Goals of therapy.

Pain relief.
Restoration of movement and activity to previous level of functioning.
Prevention of recurrence.

Rest (usually for only a few days).

Bed rest with periods of standing or sitting with a lumbar support and arm rests.
If sciatica present, strict bed rest for 3-5 days, then progress activity to include periods of standing and sitting.
Avoid any flexion of the back.

Analgesia

Pain medications, including non-steroidal, anti-inflammatory agents, aspirin, Tylenol.
Limit narcotics to acute phase only.
Muscle relaxants -- valium with marked spasm, other muscle relaxants with less degrees of spasm.
Referral to physical therapy for acute pain therapy, to include ultrasound, short wave, TENS, electro-acupuncture, traction, and manipulation.

Patient information -- Information about back care: Instruction about sitting, standing, walking, lifting, etc. obtained through physical therapy, nurses, handouts, back school.

Exercises for fitness and to prevent recurrences -- Use caution with flexion exercises.

Follow-up at two weeks and four weeks with thorough exam on each visit. If any improvement occurs, instruct the patient to return to work with limitation of activity.

Surgery for HNP is usually not indicated. Most patients heal with conservative therapy.

Referral

Immediate:

Cauda equina syndrome (acute central disc herniation).
Progressive neurologic deficit.
Severe deficit or multiple nerve root involvement.

Delayed:

Failure to improve with 6 weeks of conservative therapy.
If signs of nerve root compression are present, and no improvement occurs with 2-4 weeks of conservative therapy.

Prognosis

When patient out of work with LBP for 6 months, only 50% resume productive employment; after 12 months, only 25%; after 2 years, essentially 0%.

Prognosis may be improved by returning to work early.

References

Hall H. Examination of the patient with low back pain. Bulletin on the Rheumatic Diseases 33(4):1-8, 1983, publ: Arthritis Foundation.
Nachemson A. Work for all: for those with low back pain as well. In: Clinical Orthopaedics and Related Research, 179, Urist MR (ed). JB Lippincott, Philadelphia, 1983, pp. 77-85.
Hall H, Iceton JA. Back school: an overview with specific reference to the Canadian back education units. In: Clinical Orthopaedics and Related Research, 179, Urist MR (ed). JB Lippincott, Philadelphia, 1983, pp. 10-17.
Ruler JB. Low Back Pain. West J Med 143:259-265, 1985.
Kelen GD, Peter PE. Guidelines for use of Lumbar Spine Radiography. Ann Emerg Med 15:245-251, 1986.
Nachemson AL. Advances in Low-Back Pain. In: Clinical Orthopaedics and Related Research, 200, Urist MR (ed). JB Lippincott, Philadelphia, 1985, pp. 266-278.
Liang MH. Acute low back pain: Diagnosis and management of mechanical back pain. Primary Care 15(4):827-847, 1988.
Fast A. Low back disorders: Conservative management. Arch Phys Med Rehabil 69:880-891, 1988.
Stankovic R, Johnell O. Conservative treatment of low back pain. Spine 15(2):120-123, 1990.
Saal JA, Saal JS. Nonoperative treatment of herniated lumbar intervertebral disc with radiculopathy. Spine 14(4):431-437, 1989.
Deyo RA, Rainville J, Kent DL. What can the history and physical examination tell us about low back pain? JAMA 268(6):760-765. 1992/ 5 Melzack, R., & Torgerson, W. S., On the Language of Pain, Anesthesiology 34;50-58, 1971.

M. Harper, MD
updated 8/30/05

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