Acute Low Back Pain Glossary

Acute Low Back Problem: Activity limitation(s) due to low back symptoms (back pain or back-related leg pain) present less than 3 months.

Biofeedback: The use of auditory and visual signals reflecting a patient's muscular activity to allow the patient to facilitate or extinguish this muscle action. In patients with low back pain, the objective is to reduce pain by reducing muscle tension.

Cauda Equina Syndrome: Compression (usually due to the extrinsic pressure of a massive, centrally herniated disc) on a sheaf of nerve roots from the lower cord segments, often resulting in bilateral motor weakness of the lower extremities, saddle anesthesia, and urine retention or incontinence from loss of sphincter function.

Chemonucleolysis: The injection of a proteolytic enzyme (e.g., chymopapain) into the herniated nucleus pulposus of a disc.

CT-myelography: Computerized tomography done after contrast media has been injected into the dural sac.

Diathermy: Therapeutic elevation of the temperature of deep tissues by means of high frequency shortwave or microwaves.

Discography: The injection of a water-soluble imaging material directly into the nucleus pulposus of a disc to assess the extent of disc damage and characterize the pain response.

Discectomy: The surgical removal of all or part of a herniated intervertebral disc compressing a nerve root. When microscopic or visually aided surgical techniques are used, this procedure is referred to as microdiscectomy. The procedure can also be done through a small incision using indirect visualization (percutaneous discectomy).

Electromyography (EMG): An examination of the electrical activity of a motor unit, useful in determining the site of injury in a peripheral nerve and in detecting spinal nerve root lesions as well as primary muscle diseases. Needle EMG involves the insertion of needle electrodes into muscle; surface EMG uses surface electrodes instead of needle insertion.

Ergonomics: The study of the proper and efficient use of the body in work and recreation, including the design and operations of machines and the physical environment.

F-wave Tests: The use of electrodiagnostic equipment to measure motor conduction through nerve roots, most frequently to assess proximal neuropathies.

Facet Joints: Synovial joints formed by the facets on the articular processes of contiguous vertebrae.

H-reflex Tests: The use of electrodiagnostic equipment to measure sensory conduction of a stimulus through nerve roots that then evoke a motor reflex, commonly employed to assess S1 radiculopathy.

Herniated Disc: Herniation of the central gelatinous material (nucleus pulposus) of an intervertebral disc through its fibrous outer covering (annulus fibrosis).

Nerve Conduction Studies: Tests of peripheral nerves performed by stimulating the nerve at one point and measuring the action potential either at another point along the nerve (sensory conduction) or of the muscle innervated by the nerve (motor conduction).

Neurogenic Claudication: Symptoms of leg pain (and occasionally weakness) on walking or standing, relieved by sitting or spinal flexion, related to neural compression, usually spinal stenosis.

Pain Drawings: Drawings by patients depicting the severity, type, and location of their pain as a technique for assessing psychological involvement in the pain complaints.

Radiculopathy: Dysfunction of a nerve root often caused by compression of the root. Pain, sensory impairment, weakness or depression of deep tendon reflexes may be noticed in the distribution of nerves derived from the involved nerve root.

Saddle Anesthesia: Loss of sensation in the skin over the perineum indicative of dysfunction of sacral nerve roots.

Sciatica: Pain radiating down the leg(s) below the knee along the distribution of the sciatic nerve, usually related to mechanical pressure and/or inflammation of lumbosacral nerve roots.

Sensory Evoked Potentials (SEP): The use of electrical stimuli applied to specific nerves or dermatomes to assess the normalcy of nerve responses.

Spinal Manipulation: Manual therapy for symptomatic relief and functional improvement of the back in which loads are applied to the spine using short or long lever methods. The selected spinal joint is moved to its end range of voluntary motion, followed by application of an impulse load.

Spinal Stenosis: A narrowing of the spinal canal that may produce a bony constriction of the cauda equina and the emerging nerve roots.

Spondylolisthesis: Forward subluxation of the body of a lumbar vertebra on the vertebra below.

Spondylolysis: A fracture or cleft in the vertebral body, often through the posterior vertebral arch, loosening its normally firm attachment to contiguous vertebrae.

Straight Leg Raising (SLR):
A procedure of stretching the sciatic nerve to see if radicular symptomatology is reproduced. Each hip is alternately flexed with the knee extended; the extent to which each leg can be lifted is noted. Reproduction of the patient's sciatica when the unaffected leg is lifted is evidence of a positive "crossed" straight leg raising test.

Thermography: A procedure that images the infrared radiation (heat) emitted from body surfaces. In patients with low back problems, thermographic image patterns of the back and lower extremities are measured.

Transcutaneous Electrical Nerve Stimulation (TENS): A small battery-operated device, worn by the patient, which provides continuous electrical pulses via surface electrodes with the goal of providing symptomatic relief by modifying pain perception.

Traction: When used for low back problems, intermittent or continuous force is applied along the axis of the spine in an attempt to elongate the spine. The type most commonly used for low back problems is pelvic traction in which a girdle around the patient's pelvis is attached to weights hung at the foot of the bed.

Trigger Point: A well localized point of tenderness. In low back problems, these points are usually located in the paravertebral areas.

Visual Analog Scales: A visual means by which a patient can quantify pain. The patient marks a point corresponding to the intensity of his pain on a line, one end of which represents no pain and the other end, severe, incapacitating pain.