Lower extremity pain and numbness is very common in clinical practice, and there are two main causes: 1, nerve root compression due to disc herniation, resulting in conduction pain and numbness. 2, soft tissue near the lumbar spine, joint injury resulting in pain and numbness. So how to determine whether the patient’s pain and numbness is from the intra-vertebral canal (herniated disc compression of nerve roots) or extra-vertebral canal (soft tissue injury near the lumbar spine) lesions? Clinically, we most commonly use the straight leg raise and straight leg raise strengthening test. The patient lies on his back with both lower limbs extended, the examiner holds the patient’s knee with one hand to straighten the knee joint, and holds the ankle with the other hand and slowly raises it until the patient has radiating pain in the lower limbs, and records the angle between the lower limbs and the bed at this time, which is the straight leg raise angle. Normal people can generally reach 80-90°. The degree of straight leg elevation can vary greatly between individuals and should be compared on both sides. If the elevation is less than 70° and is accompanied by radiating pain in the posterior aspect of the lower extremity, it is positive. When sciatica occurs with straight leg elevation, slightly lower the angle of the affected limb being elevated until the pain basically disappears, and then passively dorsiflex the ankle joint, it is positive if there is a further increase in nerve tension causing pain. This test can help to identify whether a positive straight leg raise test is due to nerve or muscle factors. If the lower extremity elevation is limited due to muscular factors such as the iliotibial bundle and popliteal muscles, the strengthening test is negative. If it is caused by nerve root compression, the radiating pain will be significantly worse in this case. This test combined with the straight leg elevation test is double positive and has greater significance. The following three tests have great clinical significance in diagnosing and identifying lumbar pain caused by lesions inside and outside the lumbar spinal canal. 1, lumbar scoliosis test: (1) method of operation: the patient is in an upright position and keeps the whole body muscles relaxed, the heels are close together, and the waist is moderately tilted back. ① Affected lateral bending test: the examiner is located behind the patient and the same direction as the patient, one hand on the affected side of the pelvis of the hip lateral fixed pelvis, the other hand pressed the Jian side of the shoulder above the reverse force (note: the patient passive, the examiner active force), the patient’s lumbar spine passive to the affected side bending, when bending to the extreme, at this time, ask the patient whether the affected side of the lumbosacral deep pain or concurrent hip and lower limb radiating pain or numbness If so, the patient must use a finger to point out the specific location where the clinical signs are induced. Meaning: At this time, the intervertebral foramen on the affected side is narrowed, and if there is an aggravation or recurrence of symptoms, it is an intravertebral cause. ② healthy side bending test: the inspector hands switch positions, the same method will be the patient’s lumbar spine passive bending to the healthy side, when bending to the extreme, at this time, ask the patient whether the affected side of the lumbar pain signs elicited. (2) Clinical significance: ① If the spinal bend to the affected side triggers deep lumbosacral pain or is complicated by radiating pain or soreness in the buttocks and lower extremities, it is a positive sign and can be judged to have intraspinal pathogenic factors. The test is also positive when the spine bends to the healthy side to the extreme, so that the deep lumbosacral pain and lower limb signs induced by the original lateral bending test disappear completely. ②If the spine is bent to the healthy side and there is pain on the affected side of the back, it can be judged as soft tissue damage outside the lumbar spinal canal. ③ If either the spine bends to the affected side or the healthy side, it leads to lumbar or lumbosacral pain, it is judged to be lumbago caused by mixed lesions inside and outside the lumbar spinal canal. 2.Thoracoabdominal pillow test (1)Operation method: First, let the patient lie prone on the examination bed, and the examiner presses deeply with the finger in the intervertebral space of each vertebral plate of the lumbar vertebra 3~sacral vertebra 1 on the diseased side and the lumbar muscle next to the spinous process to find a most sensitive pressure pain point. The next step is performed while keeping the original pressure unchanged and the position of the pressure unchanged: ①. Chest pad test: first place a cotton pillow of about 20~30cm height on the patient’s chest, then press as above to ask whether the patient’s original pain symptoms have changed significantly, whether there is radiating pain or tingling sensation in the buttocks and lower limbs, if it increases, it is positive, and vice versa is negative. ②. Abdominal pad test: then put a cotton pillow on the patient’s lower abdomen, and ask the patient about the increase or decrease of pressure pain and the presence of radiating pain by the same method, if it is aggravated as positive, and vice versa as negative. (2) Clinical significance: ①If the pad chest test is positive and the pad abdominal test is negative, it suggests a lesion in the lumbar spinal canal or a lesion mainly in the lumbar spinal canal. ②If the pad thoracic test is negative and the pad abdominal test is positive, the possibility of intra-lumbar spinal canal pathology is basically ruled out, and extra-spinal canal soft tissue damage lumbago can be considered. ③If the pad thorax and pad abdomen tests are positive, then it should be judged as lumbar leg pain caused by mixed lesions inside and outside the lumbar spinal canal. (3) Tibial nerve flick test: (1) Operation method: the patient is in prone position, the examiner lifts the affected ankle with one hand and makes the knee joint flex 90°, so that the soft tissue of popliteal fossa is in a completely relaxed state (the standard for checking whether the knee joint is completely relaxed: the weight of the patient’s lower leg is completely borne by the examiner’s hand, and the immediate fall of the lower leg after releasing the hand is an objective indicator of the patient’s lower leg being completely relaxed). The middle finger or index finger of the examiner’s other hand finds the tibial nerve trunk in the popliteal fossa and gently plucks the tibial nerve trunk passing under the fascia from the posterior medial side of the popliteal fossa (note: do not press heavily or deeply to stimulate the posterior knee capsule), and then asks the patient if there is any local pain and conductive soreness on the posterior side of the calf. The same comparative examination is then done in the popliteal fossa on the healthy side. (2) Clinical significance: Any local pain or conductive soreness of the calf when flicking the tibial nerve trunk during the examination is considered positive for this test. If the finger presses the nerve trunk or the posterior knee capsule heavily, false-positive signs may be elicited. Where intraspinal pathogenic factors irritate the lumbar nerve roots, the tibial nerve flick test is mostly positive, but it should be combined with the positive signs of the pad chest pad test and the scoliosis test. If the latter two tests are completely negative and only the tibial nerve flick test is positive, then irritation of the sciatic nerve trunk by the diseased gluteal muscle should be considered. A positive tibial nerve flick test combined with a positive thoracoabdominal cushion test or lumbar scoliosis test or all three tests are specific signs corresponding to the upper and lower levels of soft tissue damage in the spinal canal.