Straight leg raise | |
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![]() Straight leg test sometimes used to help diagnose a lumbar herniated disc | |
Purpose | determine if a herniated disc is the cause of leg pain |
The straight leg raise is a test that can be performed during a physical examination, with the leg being lifted actively by the patient or passively by the clinician. If the straight leg raise is done actively by the patient, it is a test of functional leg strength, particularly the rectus femoris element of the quadriceps (checking both hip flexion and knee extension strength simultaneously). If carried out passively (also called Lasègue's sign, Lasègue test or Lazarević's sign), it is used to determine whether a patient with low back pain has an underlying nerve root sensitivity, often located at L5 (fifth lumbar spinal nerve). The rest of this article relates to the passive version of the test.
With the patient lying down on their back on an examination table or exam floor, the examiner lifts the patient's leg while the knee is straight.[ citation needed ]
A variation is to lift the leg while the patient is sitting. [1] However, this reduces the sensitivity of the test. [2]
In order to make this test more specific, the ankle can be dorsiflexed and the cervical spine flexed. This increases the stretching of the nerve root and dura. [3]
If the patient experiences sciatic pain, and more specifically pain radiating down the leg (radiculopathy), when the straight leg is at an angle of between 30 and 70 degrees, then the test is positive and a herniated disk is a possible cause of the pain. [4] A negative test suggests a likely different cause for back pain.[ citation needed ]
A positive straight leg test reproduces radiating leg pain. If it only causes back pain, then the test is negative.
A meta-analysis reported the straight-leg test as having: [5]
If raising the opposite leg causes pain (cross or contralateral straight leg raising):
Lasègue's sign was named after Charles Lasègue (1816–1883). [6] In 1864 Lasègue's medical student J.J. Forst described the signs of developing low back pain while straightening the knee when the leg has already been lifted. In 1880 Serbian doctor Laza Lazarević described the straight leg raise test as it is used today, so the sign is often named Lazarević's sign in Serbia and some other countries. [7]
Back pain is pain felt in the back. It may be classified as neck pain (cervical), middle back pain (thoracic), lower back pain (lumbar) or coccydynia based on the segment affected. The lumbar area is the most common area affected. An episode of back pain may be acute, subacute or chronic depending on the duration. The pain may be characterized as a dull ache, shooting or piercing pain or a burning sensation. Discomfort can radiate to the arms and hands as well as the legs or feet, and may include numbness or weakness in the legs and arms.
Sciatica is pain going down the leg from the lower back. This pain may go down the back, outside, or front of the leg. Onset is often sudden following activities like heavy lifting, though gradual onset may also occur. The pain is often described as shooting. Typically, symptoms are only on one side of the body. Certain causes, however, may result in pain on both sides. Lower back pain is sometimes present. Weakness or numbness may occur in various parts of the affected leg and foot.
Back injuries result from damage, wear, or trauma to the bones, muscles, or other tissues of the back. Common back injuries include sprains and strains, herniated discs, and fractured vertebrae. The lumbar spine is often the site of back pain. The area is susceptible because of its flexibility and the amount of body weight it regularly bears. It is estimated that low-back pain may affect as much as 80 to 90 percent of the general population in the United States.
The sacroiliac joint or SI joint (SIJ) is the joint between the sacrum and the ilium bones of the pelvis, which are connected by strong ligaments. In humans, the sacrum supports the spine and is supported in turn by an ilium on each side. The joint is strong, supporting the entire weight of the upper body. It is a synovial plane joint with irregular elevations and depressions that produce interlocking of the two bones. The human body has two sacroiliac joints, one on the left and one on the right, that often match each other but are highly variable from person to person.
Spondylosis is the degeneration of the vertebral column from any cause. In the more narrow sense it refers to spinal osteoarthritis, the age-related degeneration of the spinal column, which is the most common cause of spondylosis. The degenerative process in osteoarthritis chiefly affects the vertebral bodies, the neural foramina and the facet joints. If severe, it may cause pressure on the spinal cord or nerve roots with subsequent sensory or motor disturbances, such as pain, paresthesia, imbalance, and muscle weakness in the limbs.
Lordosis is historically defined as an abnormal inward curvature of the lumbar spine. However, the terms lordosis and lordotic are also used to refer to the normal inward curvature of the lumbar and cervical regions of the human spine. Similarly, kyphosis historically refers to abnormal convex curvature of the spine. The normal outward (convex) curvature in the thoracic and sacral regions is also termed kyphosis or kyphotic. The term comes from Greek lordos 'bent backward'.
Degenerative disc disease (DDD) is a medical condition typically brought on by the aging process in which there are anatomic changes and possibly a loss of function of one or more intervertebral discs of the spine. DDD can take place with or without symptoms, but is typically identified once symptoms arise. The root cause is thought to be loss of soluble proteins within the fluid contained in the disc with resultant reduction of the oncotic pressure, which in turn causes loss of fluid volume. Normal downward forces cause the affected disc to lose height, and the distance between vertebrae is reduced. The anulus fibrosus, the tough outer layers of a disc, also weakens. This loss of height causes laxity of the longitudinal ligaments, which may allow anterior, posterior, or lateral shifting of the vertebral bodies, causing facet joint malalignment and arthritis; scoliosis; cervical hyperlordosis; thoracic hyperkyphosis; lumbar hyperlordosis; narrowing of the space available for the spinal tract within the vertebra ; or narrowing of the space through which a spinal nerve exits with resultant inflammation and impingement of a spinal nerve, causing a radiculopathy.
Cauda equina syndrome (CES) is a condition that occurs when the bundle of nerves below the end of the spinal cord known as the cauda equina is damaged. Signs and symptoms include low back pain, pain that radiates down the leg, numbness around the anus, and loss of bowel or bladder control. Onset may be rapid or gradual.
Waddell's signs are a group of physical signs, first described in a 1980 article in Spine, and named for the article's principal author, Professor Gordon Waddell (1943–2017), a Scottish Orthopedic Surgeon. Waddell's signs may indicate non-organic or psychological component to chronic low back pain. Historically they have also been used to detect malingering in patients with back pain. While testing takes less than one minute, it has been described as time-consuming and alternatives have been proposed.
Foot drop is a gait abnormality in which the dropping of the forefoot happens due to weakness, irritation or damage to the deep fibular nerve, including the sciatic nerve, or paralysis of the muscles in the anterior portion of the lower leg. It is usually a symptom of a greater problem, not a disease in itself. Foot drop is characterized by inability or impaired ability to raise the toes or raise the foot from the ankle (dorsiflexion). Foot drop may be temporary or permanent, depending on the extent of muscle weakness or paralysis and it can occur in one or both feet. In walking, the raised leg is slightly bent at the knee to prevent the foot from dragging along the ground.
Failed back syndrome or post-laminectomy syndrome is a condition characterized by chronic pain following back surgeries. Many factors can contribute to the onset or development of FBS, including residual or recurrent spinal disc herniation, persistent post-operative pressure on a spinal nerve, altered joint mobility, joint hypermobility with instability, scar tissue (fibrosis), depression, anxiety, sleeplessness, spinal muscular deconditioning and even Cutibacterium acnes infection. An individual may be predisposed to the development of FBS due to systemic disorders such as diabetes, autoimmune disease and peripheral blood vessels (vascular) disease.
A spinal disc herniation is an injury to the intervertebral disc between two spinal vertebrae, usually caused by excessive strain or trauma to the spine. It may result in back pain, pain or sensation in different parts of the body, and physical disability. The most conclusive diagnostic tool for disc herniation is MRI, and treatment may range from painkillers to surgery. Protection from disc herniation is best provided by core strength and an awareness of body mechanics including good posture.
Radiculopathy, also commonly referred to as pinched nerve, refers to a set of conditions in which one or more nerves are affected and do not work properly. Radiculopathy can result in pain, weakness, altered sensation (paresthesia) or difficulty controlling specific muscles. Pinched nerves arise when surrounding bone or tissue, such as cartilage, muscles or tendons, put pressure on the nerve and disrupt its function.
Neurogenic claudication (NC), also known as pseudoclaudication, is the most common symptom of lumbar spinal stenosis (LSS) and describes intermittent leg pain from impingement of the nerves emanating from the spinal cord. Neurogenic means that the problem originates within the nervous system. Claudication, from Latin claudicare 'to limp', refers to painful cramping or weakness in the legs. NC should therefore be distinguished from vascular claudication, which stems from a circulatory problem rather than a neural one.
A GALS screen is an examination used by doctors and other healthcare professionals to detect locomotor abnormalities and functional disability relating to gait, arms, legs and the spine.
Spinal decompression is the relief of pressure on the spinal cord or on one or more compressed nerve roots passing through or exiting the spinal column. Decompression of the spinal neural elements is a key component in treating spinal radiculopathy, myelopathy and claudication.
Spinal stenosis is an abnormal narrowing of the spinal canal or neural foramen that results in pressure on the spinal cord or nerve roots. Symptoms may include pain, numbness, or weakness in the arms or legs. Symptoms are typically gradual in onset and improve with leaning forward. Severe symptoms may include loss of bladder control, loss of bowel control, or sexual dysfunction.
The term sacroiliac joint dysfunction refers to abnormal motion in the sacroiliac joint, either too much motion or too little motion, that causes pain in this region.
Femoral nerve stretch test, also known as Mackiewicz sign, is a test for spinal nerve root compression, which is associated with disc protrusion and femoral nerve injury.
The shoulder abduction relief test, also called Bakody's test, is a medical maneuver used to evaluate for cervical radiculopathy. Specifically, this test is used to evaluate for nerve root compression at C5-C7. It is often used when a patient presents with neck pain that radiates down the ipsilateral upper extremity. The patient's shoulder is abducted by lifting the affected arm above their head either actively or passively. A decrease in radicular symptoms upon shoulder abduction would be considered a positive Bakody's sign and is indicative of nerve root compression.