LOW BACK PAIN

Case Scenario

Mr B is a 45 year old teacher. He has this low back pain for 3 weeks and the pain came on when he was playing basketball. In the past 2 weeks he has noticed a sharp pain down the back of his right leg which goes right down to his ankle and worse on coughing or sneezing. He has no bladder or bowel disturbance

Approach

(1) Rapport(2) Site of pain(3) Seek permission to conduct examination +

undress appropriately down to underwear(4) Patient standing: inspection(5) Patient supine: SLR (Lasague’s sign + Kernig’s

sign)(6) Tests of peripheral nerve function lower limbs(7) Patient prone: tenderness including sacro-iliac

joints(8) Patient sitting down: Slump test

What is back pain?

Surface anatomy landmarks

Surface anatomy landmarks: IS LT 12, 10?

(1) Iliac crests (IC), posterior(2) Superior iliac spines (PSIS). Spinous process

of L4 lumbar vertebra lies at or just below the level of the iliac crest.

(3) Lumbosacral junction (=) lies 10–15° superiorly and toward the midline from the PSISs.

(4) T12 can be located by counting spinous processes back from the lumbosacral junction.

(5) T10 is at a line drawn along the 12th rib and continued to the midline to meet its contralateral fellow

History back pain

(1) Circumstances associated with pain onset(2) Primary site of pain(3) Radiation of pain(4) Character of pain (eg. is pain throbbing, sharp, aching)(5) Intensity of pain (eg. on visual analogue scale)– at rest – on

movement– at present– during past week– highest level(6) Factors altering pain– what makes it worse?– what makes it

better?(7) Associated symptoms (eg. nausea)(8) Temporal factors– is pain present continuously or otherwise?(9) Effect of pain on activities(10) Effect of pain on sleep(11) Medications taken for pain Other treatments used for pain(12) Health professionals consulted for pain

Functional tests

Gait

Moaning and groaning of the back

Inspection + palpation

Observe patient standing front, back + sides for BAGS(i) Body habitus(ii) Asymmetry of posture,(iii) Gait (iv) Spinal curves, or muscle bulk, or(v) Skin abnormalities

The level of the iliac crests assessed + note any asymmetry, indicating LPSH

(i) leg length inequality(ii) a pelvic rotation(iii) a thoraco-lumbar scoliosis or(iv) inequality size of the hemipelvis.

Tips on examination

Deviation to one side during flexion or extension said to be (but has not been proven) a sign of

(i) either subtle lumbosacral instability or (ii) a significant disc bulge or prolapse Flexion in standing recorded relative to

finger tips reaching tibial tuberosity or malleoli + for side bending relative to the superior or inferior pole of the patella

Movements

Flexion

Extension

Lateral flexion bilaterally

Rotation bilaterally

Tests of peripheral nerve function lower limbs

Power: walking on toes( mainly S1), walking on heels ( mainly L5)

Squatting : exacerbates pain right sacro-iliac joint

Sensation

Reflexes

Rotation

The hips need to be stabilised to Exclude motion of the pelvis, either by

the examiner holding the hips, or by testing in the seated position.

If reproduction of pain has not occurred with these routine movements, then overpressure by the examiner in each plane can be used to further stress the spinal column

Quadrant test

The Quadrant test

The combined motion of extension, rotation and lateral flexion

Provocative test used if pain reproduction has still not occurred

Tests done with patient seated on edge of examination couch

Straight leg raise (SLR) in sitting is tested first.

The slump test ( a sign of

neuromeningeal irritation, can be added if pain reproduction has not occurred with the sitting SLR.)

Slump test

Patient lying supine Part 1

(1) Leg lengths(2) The straight leg raise test, with and

without dorsiflexion of the ankle,. Neck flexion in the slump test, + ankle dorsiflexion in SLR should make no difference to any back or leg pain in cases of hamstring tightness or pain, increase pain in cases of neuromeningeal irritation.

Straight leg rising tests

Limitation straight leg raise: nerve root irritation

(1) Nerve root does not move until the leg is raised 30 degrees( symptoms between 0 -30 degrees viewed with suspicion)

(2) Nerve root irritation do not refer to back pain, referred leg pain or hamstring tightness

(3) SLR positive : nerve root irritation of one of the nerve roots forming the sciatic nerve L4-S3(Refer pain distribution below)

Sensory segmental patterns of lumbo-sacral nerves

Sensory nerve roots Sites of involvement

L2 Proximal anterior aspect of thigh

L3 Anterior thigh

L4 Medial aspect of calf

L5 Lateral aspect of calf + medial aspect of foot

S1 Lateral aspect of foot

Femoral nerve stretch test

Implies nerve root irritation forming the femoral nerve ( L2-4)

Muscle strength lower limbs

Muscle tested Movement How to do it?

Iliopsoas Flexion of thigh at the hip

Supine position, raise leg apply downward pressure against knee, push against my hand

Thigh adductors(medial rotators of thigh)

Adduction of thigh Keep your knees apart and push in

Gluteal medius + minimus

Abduction of thigh Keep your knees together and push out

Motor + Reflexes of lumbosacral nerves

Nerve roots Motor Reflex

L2 Flexion of hip (also L3)

None

L3 Extension of knee (also L4)

Knee jerk (also L4)

L4 Extension of knee (also L3) Inversion of foot(exclusively L4) Dorsiflexion of ankle (also L5)

Knee jerk(also L3)

L5 Dorsiflexion of great toe (exclusively L5) Dorsiflexion of ankle (also L4)

None

S1 Plantar flexion of foot +toes, Eversion of foot (also L5)

Ankle jerk

Patient lying supine Part 2

(3) A screening of hip motion . Restriction of hip flexion that produces discomfort in the back +/or buttock, rather than the groin, may be due to stiffness in the lumbar spine, +/or shortening of buttock muscles and not due to hip pathology.

(4) Provocative tests purportedly of the sacroiliac joint function, namely the FABER and the FADLong tests

Faber test

FAD Long test

Palpation

Patient to lie prone. A pillow placed under the abdomen is often more comfort-able

+ allows for maximal relaxation of lumbar paraspinal muscles. A gentle palpatory screen undertaken to gauge the degree and

location of any muscle spasm, as well as changes in skin texture.

A systematic approach to further palpation . Palpation over each of the spinous processes + unilaterally on each side is performed, looking for underlying intervertebral segmental stiffness, tenderness and pain reproduction.

Systematic palpation of each segment from the thoracolumbar junction to the lumbosacral junction performed.

Palpation around the sacrum and buttock completes the examination. Remember low back pain can be referred from the thoracolumbar junction, + sacroiliac joint dysfunction

Palpation of L5 spinous process

Palpation unilaterally (tips of the thumb)

Red Flags

(1) Recent significant trauma(2) Milder trauma if age > 50 years (3) Unexplained weight loss (4) Unexplained fever (5) Immunosuppression (6) Previous or current cancer (7) Intravenous drug use (8) Osteoporosis (9) Chronic corticosteroid use (10) Age > 70 years (11) Focal neurological deficit (12) Duration >6 weeks

Terminologies

Radicular pain involves a region beyond the

spine. Radiculopathy objective loss of sensory

+ /or motor function as a result of conduction block; the features of which might include numbness, motor loss, wasting, weakness, and loss of reflexes.

Causes radicular pain

(1) Disc herniation (commonest cause)(2) Spinal stenosis(3) Synovial cysts(4) Infection(5) Infestation(6) Tumour(7) Vascular abnormalities

Natural history lumbar radicular pain

A dramatic reduction in the severity of pain with treatment limited to simple analgesics.

At 12 months, at least 50% of patients can expect to be free of leg pain, but at least 60–70% will continue to experience low back pain

Imaging

In the absence of other indications, imagingis not required for 4–6 weeks after the onset of LRP Imaging is best reserved for (i) patients who do not respond to conservative

treatment(ii) whom surgery is contemplated. In patients with a history of(iii) sciatica or(iv) in whom a ‘red flag’ condition seems

likely,appropriate imaging should be requested.

Treatment lumbar radicular pain

1. Bed rest no more effective than watchful waiting. Depending on the severity and response to medication, the early resumption of daily activities should be encouraged.

2. Clinical studies shown neither piroxicam nor indomethacin nor oral dexamethasone offer greater

analgesia than placebo. Severe pain: opioids used judiciously.

3. Efficacy physical modalities :manipulation+ traction remains controversial, + no compelling evidence to encourage their utilisation.

4. Injection techniques such as botulinum toxin,prolotherapy, or facet joint injections are irrational+

illogical.