The straight leg raising test, also known as the Lasegue sign, is a basic test for various sciatic nerve stress tests, but it is necessary to rule out the effects of stretching of the posterior capsule of the diaphragm and knee joint. The method is as follows: the patient's lower limbs are straight and supine, the examiner holds the knee of the patient with one hand to straighten the knee joint, and the other hand holds the ankle and slowly raises it until the patient has radiation pain of the lower extremity. The angle between the lower limb and the bed surface is the angle at which the straight leg is raised. Normal people can generally reach about 80 degrees, and there is no radiation pain. On this basis, the straight leg raising and strengthening test can be carried out, that is, the examiner raises the lower limb of the patient to the maximum and puts it down about 10 degrees. When the patient does not pay attention, the foot will be dorsiflexously, if it can cause lower extremity radiation pain. That is positive.

Basic Information

Specialist classification: neurological examination classification: physical examination

Applicable gender: whether men and women apply fasting: not fasting

Analysis results:

Below normal:

Normal value:
no

Above normal:

negative:
Normal people can generally reach about 80 degrees, and there is no radiation pain.

Positive:
In the straight leg raising test, when the lower limbs are raised at 0 to 20 degrees, the movement of the nerve roots in the spinal canal is not caused, so the limitation in this range is mostly caused by the tendon of the rope. After the lower limbs rise more than 30 degrees, it can cause the nerve roots to pull or move downwards. The most traction is the waist 5 nerve roots, followed by the lumbar 4 nerve roots. When the elevation angle exceeds 60 degrees, the tension of the lumbar 5 nerve root is maximized and is sufficient to move it downward in the spinal canal. Because the lumbar 5 and lumbar 4 nerve roots are subjected to a large pulling force, patients with lumbar 5 to 骶1 and lumbar 4 to 5 intervertebral discs are mostly positive for straight leg elevation test. In patients with more severe lumbar disc herniation, not only the straight leg elevation test on the affected side is positive, but also the straight leg elevation test on the healthy side can be positive. This is because the nerve root can be made when the lower limb is elevated. The dural sac is affected, which changes the relative position of the contralateral nerve root and the protrusion, and induces pain.

Tips: Check your relaxation, you should face it positively and actively cooperate with the inspection. Normal value

The result of the test was negative. Normal people can generally reach about 80 degrees, and there is no radiation pain.

Clinical significance

Abnormal result

The patient was supine and the lower extremities were flat. The examiner held the knee of the patient in one hand to straighten the knee joint, and the other hand grasped the ankle and slowly raised it until the patient developed radiation pain in the lower extremities. The lower limb and the bed surface were recorded at this time. The angle is the straight leg raising angle. Normal people can generally reach 80-90 degrees. If the elevation is less than 70 degrees and is accompanied by radioactive pain on the posterior side of the lower extremity, it is positive. Straight leg raising test in the base of the straight leg raising test

On the basis of the extension of the foot, the sciatic nerve is pulled tighter and the root pain is more positive. This test combined with the straight leg elevation test is double positive, which is more significant. In the straight leg raising test, when the lower limbs are raised at 0 to 20 degrees, the movement of the nerve roots in the spinal canal is not caused, so the limitation in this range is mostly caused by the tendon of the rope. After the lower limbs rise more than 30 degrees, it can cause the nerve roots to pull or move downwards. The most traction is the waist 5 nerve roots, followed by the lumbar 4 nerve roots. When the elevation angle exceeds 60 degrees, the tension of the lumbar 5 nerve root is maximized and is sufficient to move it downward in the spinal canal. Because the lumbar 5 and lumbar 4 nerve roots are subjected to a large pulling force, patients with lumbar 5 to 骶1 and lumbar 4 to 5 intervertebral discs are mostly positive for straight leg elevation test.

In patients with more severe lumbar disc herniation, not only the straight leg elevation test on the affected side is positive, but also the straight leg elevation test on the healthy side can be positive. This is because the nerve root can be made when the lower limb is elevated. The dural sac is affected, which changes the relative position of the contralateral nerve root and the protrusion, and induces pain.

People who need to be examined have abnormal pain when lifting their legs.

Positive results may be diseases: sciatic nerve injury, degenerative ligamentum flavum hypertrophy, iliac fascia fat sputum, lumbar spinal stenosis, third lumbar vertebrae transverse process syndrome, sciatic nerve pelvic outlet stenosis considerations

Taboo before inspection: no special contraindications.

Requirements for inspection: Check the feelings of relaxation, should face positively, and actively cooperate with the inspection.

Inspection process

The patient's lower extremities were straight and supine. The examiner held the patient's knee in one hand and straightened the knee joint. The other hand grasped the ankle and slowly raised it until the patient developed radiation pain in the lower extremities. The lower limb and bed were recorded at this time. The angle of the face.

Not suitable for the crowd

Generally no taboos.

Adverse reactions and risks

No.