Sciatica, or not? An improved SLR answers the question

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A 34-year-old female patient presents to your office with a dull achy sensation in her buttock and thigh without symptoms distal to the knee. Symptom severity and frequency have progressively increased over the last month. She has seen other chiropractors. However, they have been unsuccessful in symptom relief with spinal manipulation as their primary method of treatment. Her buttock and thigh pain is worse with sitting; however, walking alleviates symptoms quickly. There are no red flags. Orthopedic evaluation reveals a positive SLR at 70 degrees with reproduction of her chief complaint. 

In our latest blog, we will revise the traditional SLR test with a new twist to differentiate this patient's etiology. Do you want to learn about a new orthopedic examination today?

The most commonly performed test for low back pain, sciatica, or lumbar disc herniations is the Straight Leg Raise (SLR). (1) Recently, Pesonen et al. modified the SLR allowing you to isolate your patient's problems with greater diagnostic reliability. In the following blog, you will learn about this new test—the Extended SLR (ESLR), and why it may be your new favorite test for your patients with sciatica.

What is the SLR?

The clinician progressively lifts the supine patient’s straightened leg until symptoms are reported. Reproduction of radicular symptoms in the 30-70 degree range, suggests the involvement of the L4/5 or L5/S1 nerve roots from radiculopathy or dural irritation. Also called Lasegue's Test.

What are the limitations of the SLR?

• The ambiguity of results if symptoms are elicited below 30 degrees or above 70 degrees

• Requires Braggard’s Test to differentiate musculoskeletal from neurologic symptoms

• Very low specificity when performed in isolation.

• Unable to discern neural symptoms from musculoskeletal etiologies.

What is the ESLR?

The clinician progressively lifts the supine patient’s straightened leg until radicular symptoms are reported. The clinician then performs ankle dorsiflexion to increase neural tension for thigh symptoms, or hip internal rotation to increase neural tension for lower leg symptoms. Intensification of symptoms during either neural differentiation maneuver suggests a neurologic origin (vs. musculoskeletal origin). (2)

ChiroUp Pro Tip

These movements increase tension on neural structures while not affecting the local musculoskeletal structures. These movements are proximal or distal to symptoms, not to affect local MSK structures.

If the patient is experiencing distal (below the knee) symptoms: use hip internal rotation to increase neural tension.

If the patient is experiencing proximal (above the knee) symptoms: increase neural tension, use ankle dorsiflexion.

Now, back to the 34-year-old patient from the beginning of the blog. There is an excellent chance this patient is suffering from Piriformis Syndrome (PS). PS is a common diagnosis missed with a traditional SLR. Patients with piriformis syndrome often have compression of the fibular tract of the sciatic nerve. This nerve can create symptoms from the buttock to the anterolateral leg. The SLR will mechanically compress the sciatic nerve's fibular tract with increased hip flexion. Peak compression occurs as the piriformis transitions from an external to internal rotator of the hip ~70 degrees.

The ESLR may help differentiate lumbar radiculopathy versus peripheral neuropathy in this case.  During the ESLR, symptoms may present at a specific degree of hip flexion. However, nerve compression will not increase with ankle dorsiflexion. Remember that with neurologic signs above the knee, use a distal differentiator. So, the SLR tells us we have nerve irritation, but the ESLR tells us the compression is likely mechanical and above the knee.

For more information on Piriformis Syndrome, check out the complete condition reference in ChiroUp with all the orthopedic tests, treatments, and rehabilitation exercises.

• References

  1. Konstantinou K, Dunn KM, Ogollah R, Vogel S, Hay EM. Characteristics of patients with low back and leg pain seeking treatment in primary care: baseline results from the ATLAS cohort study. BMC Musculoskelet Disord. 2015;16(1):332.

  2. Pesonen, J., Shacklock, M., Rantanen, P. et al. Extending the straight leg raise test for improved clinical evaluation of sciatica: reliability of hip internal rotation or ankle dorsiflexion. BMC Musculoskelet Disord22, 303 (2021).