Clinical Examination for Low Back Ache

Courtesy: Prof Nabil Ebraheim, University of Toledo, Ohio, USA

Low back pain is common. There are several clinical evaluation tests used to assess patients with low back pain.

1-Straight leg raising test: elevation of a painful limb causes sciatica and radicular pain. The test is positive when the pain occurs with less than 60 degrees of hip flexion. The test stretches the sciatic nerve. When the sciatic nerve itself or one of the nerve roots irritated, the patient will experience pain that travels to the leg. The test can be modified by bending the knee. When the knee is bent, the pain gets better due to relaxing of the sciatic nerve. Once the patient feels the pain, lower the leg slightly and dorsiflex the foot.

2-Contralateral straight leg raising test: elevation of the non-involved leg, which is the contralateral leg, causes back pain and leg pain on the involved side.

3-Femoral nerve stretch test: this test is rarely done. The hip extension will stretch the femoral nerve. A positive test means the L3, L4 nerve roots are involved. The test will stretch the femoral nerve and is positive when pain Is felt on the ipsilateral anterior thigh.

4-Faber test: helpful in determining the presence of SI joint problems. With the patient lying supine on the examination table, the leg of the affected side should be placed into external rotation and with the foot onto the opposite knee. The examiner will press down gently but firmly on the flexed knee and the opposite anterior superior iliac crest. The position of the left will be flexion, abduction and external rotation of the hip. The Faber test is suggestive, but not a confirmatory test, because any condition in the lower back will be painful when you perform this maneuver. SI joint injection is confirmatory for SI joint problems. Some physicians believe in this and some do not. If you inject the SI joint with numbing medicine and some steroids and the patient gets better temporarily, then the problem is in the SI joint. The symptoms of SI joint and other back problems can overlap and everything can hurt:
•Nerves •Tendons •Intervertebral discs •Facet joints •Ligaments •Muscles •Nerve irritation
The examiner has to have a detailed plan and work through algorithms. If the patient points towards one side of the lower back and the Faber test is positive, then it is probably a good idea to inject the SI joint and see the response of the patient in addition to other methods of treatment. It is up to you if or when you give the injection. It is your clinical judgment that decides the treatment.

5-Movement of the spine tests:

•flexion: pain in the lower back with lumbar flexion suggests a disc related disorder. •Extension: patient with spinal stenosis, spondylolysis, spondylolisthesis or facet disease will demonstrate pain with extension of the lower back. Because of the pain experienced with extension of the spine, people suffering from spinal stenosis gain relief from leaning forward.

6-Myelopathic signs: a positive clonus sign or Babinski’s sign indicated an upper motor neuron lesion that will not occur from a lumbar spine pathology.

•Gait disturbance: means there is myelopathy. Need to check the thoracic and cervical spine for spinal cord involvement even if they have a huge disc in the lumbosacral MRI. The lower lumbar spine deals with nerve roots and not the spinal cord itself.
•Clonus sign: nonvoluntary sustained movement of the ankle muscles with frim passive continuous stretch.
•Babinski’s sign: the test is performed by stimulating the outside portion of the sole of the foot. The test is positive when running a sharp instrument along the lateral border of the forefoot from the calcaneus produces extension of the big toe and fanning of the other toes. The test is negative if no reaction occurs or if the toes all bunched up.

7-Wadell’s signs (nonorganic findings): extremely controversial. Wadell’s sign is a set of physical signs used to indicate if chronic low back pain is due to non-organic or psychological components. There are five categories of tests included in the Wadell’s sign:

•Simulation tests
•Tenderness tests
•Flip test
•Nonanatomic weakness and sensory findings.
•Overreaction

Nonorganic physical exam findings determine if the patient is over exaggerating with nonanatomic findings. The clinician should be alert to the possibility that the patient may be exaggerating the symptoms possibly for a secondary gain. The clinicians should not be accusatory. Different patients may perceive their pain differently. We don’t understand how pain is produced, so we can’t simply accuse the patients of over exaggerating their symptoms.