The patient sits upright on the examining table with the legs hanging loosely over the edge of the table. The hips are in a neutral position and the hands are placed behind the back.
The examination is performed step by step as following:
First the patient is asked to “slump” the back into thoracic and lumbar flexion while the examiner supports the head to keep it in a neutral position.
With one arm , the examiner then applies pressure across the shoulders to maintain increased flexion in the thoracic and lumbar spine.
At the same time, the patient is asked to actively flex the cervical spine and head as far as possible.
Using the same hand, the examiner then applies pressure to maintain flexion in all three parts of the spine.
With the other hand the examiner holds the patient’s foot in maximum dorsiflexion. In this position the patient is asked to actively straighten the knee as much as possible.
The test is then repeated with the other leg and, if possible, with both legs at the same time.
What does a positive Slump Test mean?
The test can cause impingement or irritation of the dura and/ or nerve roots, with pain radiating down into the areas supplied by the sciatic nerve.
If the patient is unable to extend the knee because of pain, the examiner reduces the pressure on the cervical spine and asks the patient to slowly raise the head.
The Slump test is considered to be positive if the patient is then able to extend the knee further without pain or with less pain, indicating that neural structures are affected.
During the course of the test, pains may occur that must be defined in the differential diagnosis, these include:
Facet joint arthritis
Tight hamstring muscles.
Limited knee and ankle joint mobility.
Sensitivity & Specificity
A prospective case control study by Javid Majlesi that was done on 75 patients with complaints suggestive of lumbar disc herniation, he found that the slump test has a high Sensitivity and Specificity as following 1:
Sensitivity: 84 %
Specificity: 83 %
The Conclusion of the study was that the Slump test might be used more frequently as a sensitive physical examination tool in patients with symptoms of lumbar disc herniations, while the Straight Leg Raise SLR (Lasegue Test) may especially help identify patients who have herniations with root compression that requiring surgery.
Another study 2 comparing Straight Leg Raise SLR (Lasegue Test) and slump test, it showed that the sensitivity of slump test was 80 % compared to 87 % for SLR test , while the specificity of slump test was 71 % compared to 42 % of SLR test.
Accuracy of Slump test VS Straight Leg Raise SLR (Lasegue Test)
Bechterew’s test is an abbreviated slump test, performed by asking the seated patient to actively extend his or her uninvolved leg at the knee, to lower that leg and then subsequently extend the involved leg. If symptoms are not produced, the patient is asked to extend both legs at the knee simultaneously.
A positive finding includes the reproduction of radicular pain below the knee, inability to attain full knee extension, leaning backward and bracing oneself on the table (tripod sign), or any combination thereof.
Sitting root test:
Sitting root test is another test similar to the slump test.
With the patient seated and his or her neck flexed to the chest, the clinician places one hand on the distal thigh of the tested leg to prevent hip flexion and uses the other hand to extend the lower leg at the knee.
Any of the typical SLR responses is considered a positive finding.
If the test is negative, the clinician may increase tension placed on neural elements by adding trunk flexion.
The slump test assesses the excursion of neural tissues within the vertebral canal and intervertebral foramen58 and detects impairments to neural tissue mobility from a number of sources.
The slump test enables the tester to detect adverse nerve root tension caused by spinal stenosis, extraforaminal lateral disk herniation, disk sequestration, nerve root adhesions, and vertebral impingement.
One study 3 found that a positive slump test was recorded in 57% of subjects with apparent repetitive grade I hamstring strains suggesting some form of relationship between the hamstrings and the sciatic nerve.
The only advantage of the slump test over the Straight Leg Raise SLR (Lasegue Test) is that it increases the compression forces through the intervertebral disks and will highlight the presence of dural adhesions.
Javid Majlesi, Halit Togay, Halil Unalan, Sadk Toprak. The sensitivity and specificity of the Slump and the Straight Leg Raising tests in patients with lumbar disc herniation. J Clin Rheumatol. 2008 Apr;14(2):87-91. doi: 10.1097/RHU.0b013e31816b2f99. PMID: 18391677.
V R P M’kumbuzi, J T Ntawukuriryayo, J D Haminana, J Munyandamutsa, E Nzakizwanimana. Accuracy of straight leg raise and slump tests in detecting lumbar disc herniation: a pilot study. Cent Afr J Med. Jan-Apr 2012;58(1-4):5-11. PMID: 26255334.
Turl SE, George KP. Adverse neural tension: a factor in repetitive hamstring strain? J Orthop Sports Phys Ther. 1998 Jan;27(1):16-21. doi: 10.2519/jospt.19184.108.40.206. PMID: 9440036.
Maitland GD. The slump test: exam ination and treatm ent. Aust J Physiother 1985;31(6):215–219.