Medical Terms

During the course of dealing with your injury, you’re likely to have a lot of complex terms and jargon thrown your way by insurance adjusters, medical providers, employers and even other lawyers. In some cases, those words may be intended to intimidate or confuse you and in others, they may just be terms of art.

Part of the way we help relieve your stress is to make sure you understand what’s going on, so that you regain a sense of control and can knowledgably participate in the process and resolution of your case.  One way we do this is to talk to you person-to-person, without the typical “lawyer speak.”

To learn more about a specific term, scan our list or enter the word/s you’re looking for to see an easy-to-understand explanation.




Lateral movement of the limbs away from the midline of the body. Opposite of Adduction.

Aberrant intersegmental motion

Abnormal movement between two adjacent vertebral segments.

Acceleration-deceleration injury

Injury syndromes commonly associated with hyperextension-hyperflexion of the neck. Most often caused by a rear-end auto accident.


The cup-shaped cavity of the hip joint at the base of the pelvis into which the ball-shaped head of the thighbone (femur) fits.  It is the “socket” of the “ball and socket” of the hip joint.

Achilles tendinitis

Inflammation, swelling and pain of the tendon which attaches the heel bone to the calf muscle.

Acquired spinal stenosis

Spinal stenosis usually due to degenerative changes.


The triangular projection of the scapula that forms the point of the shoulder and articulates with the clavicle.

Active range of motion

Range of motion in the cervical, thoracic, lumbar spine, or any other joint of the body which patient does under his or her own power.

Activities of daily living

The normal daily activities and functions a person must perform or fulfill to maintain cleanliness, self-grooming, home maintenance, eating, working and recreation.


The application of manual pressure to specific points along acupuncture meridian pathways for the purpose of decreasing pain. Pain relief is believed to be accomplished by stimulating or sedating the selected acupuncture points.


An oriental medicine treatment modality where needles are inserted in particular points on the “meridians” of Qi (channels of energy in the body). This is believed to have neurophysiologic effects which decrease pain and promote healing by balancing Qi.


A recent onset of an injury or problem. The precise time line of an acute condition can range from hours after onset to 16 weeks depending upon the standard of the particular physician or treatment provider.

Acute exacerbation

A sudden aggravation of symptoms or increase in severity of an already existing condition without re-injury or trauma.

Adaptive changes

Changes in a spinal segment which occur secondarily to another biomechanical problem in the spine. This usually involves loss of range of motion in a specific direction to compensate for the trauma at another area.

Adaptive scoliosis

A lateral curvature of the spine, which is secondary to soft tissue biomechanical imbalance and not to bony changes (structural).


Movement of a limb toward the middle of the body. Opposite of Abduction.*


Fibrosis tissue and scar tissue that bind together tissues which are usually not attached.


A chiropractic term which describes the skilled application of force to a joint or motion segment to improve intersegmental motion, decrease localized muscle tension, and restore normal motion and position.


Abbreviation for Activities of Daily Living.

Adson’s test

A physical exam test used in evaluation of thoracic outlet syndrome at the junction of the brachial plexus and the scalene muscles of the neck. The patient is placed in the sitting position with one arm straight out to the side and extended slightly backwards. The patient then takes a deep breath and turns the head toward the side being tested. A positive test is loss or diminishment of the wrist pulse on the side being tested.

Afferent nerve fibers

Nerve fibers which carry sensory impulses to the central nervous system.


A graft taken from another person (living or dead).

Ankylosing spondylitis

A chronic inflammatory disease wherein the spinal motion segments and the sacroiliac joints progressively fuse, resulting in painful restriction of spinal movement.


A joint condition of decreased or full loss of range of motion, often due to advanced degenerative changes. A spinal segment which is fused can be said to be “ankylosed”. Also, the fusion of a joint either by advanced degeneration or by artificial means (surgery).

Annular bulge

A bulging out of the annulus fibrosis, the tough fibrosis outer ring that provides support to the disc, which is diffuse and, usually due to degenerative changes or trauma, leading to degenerative changes. This condition may include partial rents or tears in the annulus fibrosis.

Annular rent

Another way to describe a tear in the annulus, usually seen during discography, less commonly on MRI, or during surgery. These tears can be traumatic in origin. Also known as an annular fissure.


See Annulus Fibrosis.

Annulus fibrosis

The outer covering of the softer, gel-like nucleus pulposus of the intervertebral disc. The intervertebral discs are located between each of the vertebrae of the spine.


Front side, the opposite of posterior. Synonymous with ventral.

Anterior cruciate ligament 

The anterior cruciate ligament (ACL) starts in the front of the lower leg bone (tibia) and attaches to back of the thighbone (femur).  The ACL resists forward slippage of the lower leg bone under the thighbone.  The posterior cruciate ligament (PCL) starts in the back of the lower leg bone (tibia) and attaches to the front portion of the thighbone (femur).  The PCL resists backward slippage of the lower leg bone (tibia) under the thighbone (femur).  The ACL is the most commonly injured ligament of the knee.  A strain or partial tear might heal and only require physical therapy.  Complete tears often require surgical repair, which is commonly done arthroscopically.

Anterior disc herniation

An extrusion of the nucleus pulposus through the front side of the annulus of the disc.

Anterior discectomy and fusion

The surgical removal of an abnormal intervertebral disc and replacement with bone graft and/or surgical hardware for fusion, using an anterior approach to the spine.

Anterior drawer test

If the anterior cruciate ligament (ACL) becomes injured or torn, it may become lax or loose.  One test for this laxity is the anterior drawer test.  Your doctor will have you lay on the exam table on your back with your hips and knees bent.  He or she will sit on the edge of the table with his/her leg over the top of your foot.  The doctor grasps the lower leg (tibia) with both hands just below the knee joint.  The patient is told to relax.   The doctor attempts to pull the lower leg forward and feels the amount of motion between the lower leg (tibia) and thigh (femur).  The doctor will compare the motion from side to side.  An increase in motion or lack of a firm endpoint suggests a tear of the ACL.

Anterior scalene syndrome

Compression of the bundle of nerves, veins and arteries as it passes between the anterior and middle scalene muscles. This is a cause of thoracic outlet syndrome or cervicobrachial syndrome, as this is one of the more common areas of entrapment.


A vertebral segment which is moved forward relative to the segment below.

AO Joint

Atlanto-occipital joint is the vertebral joint formed by the occiput (a portion of the skull) at the base of the skull resting upon the atlas or first cervical vertebra (C1).


Anterior to Posterior or front to back. This refers to the orientation of the patient to the x-ray beam. With AP films the patient faces away from the x-ray film and faces the x-ray machine. The x-ray photons pass from anterior to posterior through the patient. The image produced is a “front to back” view of the patient.

Applied kinesiology

A chiropractic diagnostic technique based on the theory the neuromuscular system can be accessed through specific neuromuscular pressure points. This is usually combined with manual muscle testing to determine which muscles are weak and need to be balanced. Some chiropractors use this technique as a way to plan their adjustments and to recheck the patient following the chiropractic adjustment.

AROM exercise

An exercise designed to increase Active Range of Motion.


Joint pain.


Inflammation of the cartilage portion of a joint.


The injection of radiographic dye into a joint that is then x-rayed. The contrast dye allows for better visualization of the joint and possible irregularities. Arthrograms are being progressively replaced by MRI.


The injection of radiographic dye into a joint that is then x-rayed. The contrast dye allows for better visualization of the joint and possible irregularities. Arthrograms are being progressively replaced by MRI.

Arthroscopic surgery 

The use of a small camera at the end of a wand to perform surgery.  Usually the surgeon makes 3 holes (called portals) into the structure he/she is going to operate on (like a joint, or perhaps the abdomen).  The camera wand (arthroscope) is passed through one hole.  The other two holes are used to perform the surgery.  Sometimes a surgery is too difficult to perform arthroscopically and in those cases, the surgeon will make a larger incision that allows him/her to see the structures directly.  This is called an “open procedure.”


A disorder of a joint.

Articular dysfunction

A chiropractic term, which refers to an abnormality of spinal biomechanics involving a loss of normal movement of vertebral motion segment.

Articular fixation

A loss of one or more joint motions. One of the components of the chiropractic diagnosis of subluxation. See Subluxation. See Hypomobility.

Articular spondylolisthesis

A forward or anterior “slipping” of one vertebra in relation to another, due to trauma and/or degenerative changes within the facet  joints and/or the discs.

Articular surface

The surface of a joint, lined with cartilage and synovial fluid to lubricate joint movement.


The joint between bones. The movement of bones as a result of the joint.


Referring to the articulation of the joint between the occiput of the skull and the C1 vertebra (atlas). See AO Joint.


The first cervical vertebra which moves with the occipital bone of the skull, and the second cervical vertebra in the neck. Also known as C1.


A wasting or decrease in size, often in reference to muscle tissue.


A graft taken from the patient.

Autonomic nervous system

The part of the nervous system controlling     involuntary bodily functions, including regulation of glands, organs, and smooth muscle tissue. The autonomic nervous system acts upon these tissues to slow or initiate their function.


The pulling away of one tissue from another, either by trauma or surgery.


The armpit.



The hard, osseous material consisting of bone cells (osteocytes) embedded in a matrix of calcified intercellular material.

Bone spur

See Osteophyte.


Pertaining to the arm.

Brachial plexus

A complex network of nerve tissues in the neck and armpit, which stem from the C5-T1 nerve roots. The brachial plexus contains the nerves going to the arms.


A sound, especially an abnormal one, heard on physical examination.  It is commonly used when referring to blood flow.  Doctors may listen to your blood flow over larger arteries or the heart.

Bulging disc

Same as Disc Bulge.


Inflammation of pad-like fluid-filled sacs (bursa) found within the connecting tissue of the joints, as in the shoulder and knee.


Calcaneous (or calcaneus) 

The calcaneous is the heel bone.


Inflammation of tissues enclosing a joint.

Carpal tunnel syndrome

Soreness, tenderness, and weakness of the muscles of the thumb, index and middle fingers caused by pressure on the median nerve at the point at which it goes through the carpal tunnel of the wrist.


The dense connective tissue between the bodies of the vertebrae (the intervertebral discs) and between the articular surfaces of the joints.

Cauda equina

The end portion of the spinal cord and the roots of the spinal nerves below the first vertebra in the low back.

Central nervous system

The combination of the brain, spinal cord, and nerves that control voluntary and involuntary acts.


Centrum means “center”.  It is commonly used in reference to the bones of the spine called vertebrae.  The centrum would specifically refer to the “body” or main weight-bearing portion of the vertebra.


Referring to the neck. The cervical spine has seven vertebrae (C1 through C-7) which allow for head and neck movement.

Cervicogenic headache

A headache that originates in the neck.


A branch of the healing arts focused on human health, disease processes, and physiological and biochemical aspects of the body including structural, spinal, musculoskeletal, neurological, vascular, nutritional, emotional and environmental relationships. Chiropractic procedures include the adjustment and manipulation of the articulations and adjacent tissues of the human body, particularly of the spinal column. Included is the treatment of intersegmental dysfunction for alleviation of related functional disorders. Chiropractors do not use medications or surgery. However, nutritional supplementation may be prescribed.


A condition of long standing. Health care providers consider injuries or conditions still existing 12 weeks after the occurrence to be chronic.


The “collar bone” which articulates with the scapula, acromion and the sternum.


  Any alteration in cerebral function caused by direct or indirect (rotation) force transmitted to the head resulting in one or more of the following: a brief loss of consciousness, lightheadedness, vertigo, cognitive and memory dysfunction, tinnitus, difficulty concentrating, amnesia, headache, balance disorder, nausea or vomiting. A concussion is a brain injury.

Connective tissue

 Tissue connecting and supporting muscles, tendons, and ligaments.

Conversion disorder

A condition in which a person has neurologic symptoms that cannot be explained by medical evaluation. Psychological conflict may bring on the disorder and psychological issues are manifest in physical symptoms.  It is important to note that the person is not faking the symptoms; the symptoms are real and originate from psychological rather than physical factors.


A potent anti-inflammatory drug.


A cause of chest pain.  Costochondritis is an inflammation and associated tenderness of the cartilage (i.e., the costochondral joints) that attaches the front of the ribs to the breastbone.

Cozen’s test

A physical exam test your doctor may due to look for tennis elbow (called lateral epicondylitis). The doctor will ask you to extend your wrist and he will attempt to resist you.  If this maneuver causes pain, you may have tennis elbow.


This is the region of the body where your head meets your neck.  “Cranio” refers to the head, and “cervical” refers to the neck.

Craniosacral therapy

A manipulation-based therapy first developed by William Sutherland, D.O. It is based upon the belief that cranial plates are mobile and connected to the spinal cord and sacrum through the meninges. Some techniques concentrate on detecting cranial plates that are “out of place” and correcting these dysfunctions. While controversial, many patients report relief of headaches and tempormandibular joint pain with the technique.


Crunching, rubbing or snapping sounds heard or felt when moving a joint.


The application of ice to injury sites to reduce inflammation and pain by decreasing blood flow in the area of the injury or discomfort.

CT discogram

A discogram followed by a CT Scan. The CT scan allows visualization of the disc structure following the injection of radiographic dye during the discography procedure.

CT myelogram

A myelogram followed by a CT scan. This technique visualizes the spinal nerves as they relate to the surrounding bony structures. This study is commonly used for surgical planning.

CT scan

Also called CAT scan, Computer Tomography, Computer Assisted Tomography, or Computer Axial Tomography. The use of x-ray energy passing through the body at different angles and processed through a computer to produce a cross-sectional (axial) image of an area of the body. The current term, CT Scan, is the most accurate since reformatting has allowed other planes to be imaged besides just the axial plane.

Cubital tunnel syndrome

“Cubital tunnel” refers to a passageway along the inner part of the elbow bounded by bones, muscles and ligaments. Cubital Tunnel Syndrome involves symptoms of numbness, tingling, or weakness of the pinky and ring fingers due to compression of the ulnar nerve passing through the cubital tunnel.



Diplomate of the American Board of Chiropractic Orthopedists.


Diplomate of the American Chiropractic Board of Radiology.


Diplomate of Applied Chiropractic Science.


Abbreviation for Doctor of Chiropractic.


See Degenerative Disc Disease.


The loss of strength, flexibility and endurance due to long-term illness, injury, or lack of proper motion or exercise.


In spine surgery, the term refers to the lessening of pressure on a nerve root, spinal nerve or the spinal cord. This is also a manual therapy term referring to the lessening of pressure on a nerve or joint through manual traction.

Deep tendon reflex test

A physical exam technique used to determine the existence and functioning of the nerves connected to the tested muscle. With proper technique, in normal patients, striking the tendon of the muscle will elicit a standard contraction of the muscle, thus assuring the reflex “arc” is intact. Disruption of either the sensory or motor pathways will affect the reflex.

Deep vein thrombosis (DVT)

Thrombosis means blood clot.  A “deep vein thrombosis” is a blood clot that develops in a major vein that is usually deeper in the body (not on the surface).  DVT’s commonly occur in the legs, but they also may occur in the arms.

Degenerative changes

Degeneration of any joint due to wear and tear, trauma, or unusual postures. The degenerative changes include disc space narrowing, osteophytes or bony spurring. These type of changes can be seen both on x-ray and MRI imaging.

Degenerative disc disease

An intervertebral disc, which has suffered the effects of the aging process or the effects of trauma. A disc becomes degenerated over time, often spanning years. Often there are small circumferential tears in the annulus fibrosis, the tough outer covering of the disc. A degenerated disc is also characterized by a loss of its height due to a drying-out of the nucleus pulposus, the gelatinous material inside the disc. It is often caused by a loss of motion between the vertebrae above and below, thus decreasing the mechanical flow of nutrients to the disc.

Degenerative facet joints

Facet joints, which, as a result of age and time or trauma, have signs of arthritic changes. The degenerative arthritic changes may include thinning of joint spaces, changes in the joint and cartilage surfaces, and inflammation of the joint and connecting tissues of the joint. Degenerative facet joints may or may not be symptomatic.

Degenerative joint disease (DJD) 

In the spine, DJD refers to the inflammatory changes in the facet joint, also known as the zygapophyseal joints of the vertebral bodies. These changes often lead to bone changes and reduced range of motion at the joint. Degenerative joint disease is not limited to the spine.

Degenerative symptoms

 Pain and physical restrictions are a result of degenerative changes usually in the weight-bearing joints of the body.


The blocking of a nerve supply by trauma, degeneration or surgery.

Dermatomal somatosensory evoked potential

An electrical conductivity test specific to nerve (dermatome) patterns. See Somatosensory Evoked Potential, SSEP.


A specific sensory nerve distribution pattern, which can be outlined or traced on the skin.


Dehydration of an intervertebral disc.


See Intervertebral Disc.

Disc bulge

A broad-based enlargement of the annulus fibrosis extending past the edges of the adjoining vertebral end plates with herniation of the nucleus pulposus into or through the annulus fibrosis. See Bulging Disc.

Disc herniation

See Herniated Disc.

Disc space narrowing

A narrowing of the space between the vertebrae, produced by disc dehydration (dessication) and is often imaged by x-rays. See Degenerative Disc Disease.


The surgical removal of the bulging or extruding disc material (nucleus pulposus). Access to the bulging or extruding disc material may be had by removal of the lamina of the vertebral body (laminectomy) or the cutting of an opening in the lamina (laminotomy). Discectomy may be done in conjunction with a foraminotomy and/or a fusion.

Discogenic pain

Pain coming from the nerves embedded in the annular wall of the disc. Pain can arise from chemical or mechanical irritation of these nerves as a result of damage to the intervertebral disc. The outer portion of the annulus has sensory nerves and trauma or degenerative changes to the annulus can cause pain.


An imaging procedure which reveals the inner structure and condition of an intervertebral disc by injecting dye through a needle placed into the disc. A CT Scan is then performed to image the disc more precisely. Discography can also be used to determine if the disc is a source of pain, in addition to revealing the disc’s inner structure. Discography is often employed to determine a patient’s suitability for fusion surgery in the neck, mid back, or low back.  But more recent medical studies have recommended against its use because the inserting of the needle into the good disk is thought to cause degeneration of that disc overtime.


(1) Application of a force to mildly and temporarily release pressure from a joint. This tractioning of a joint space is for the purpose of releasing entrapped soft tissues, such as the joint capsule or spinal nerve roots. This may be performed manually, by application of weight, or mechanically; (2) An orthopedic test wherein the examiner places his/her hands under the chin/jaw and gently pulls up. This maneuver may relieve pressure from the nerve roots and discs. If the patient feels relief of symptoms, the test is “positive”; or (3) The diversion of a patient’s attention from the primary activity being performed during physical examination.

Diversified technique

A chiropractic technique in which the primary manipulative force is applied by the practitioner’s hands. See Manipulation, Chiropractic.


See Degenerative Joint Disease.


A physician graduating from a medical school of osteopathic medicine. Osteopathic doctors can use manipulation of the spine and administration of medications as part of their treatment of spinal complaints. See Osteopathic Physician. *

Dominant hand

The hand one uses most often because it is usually more coordinated and stronger than the non-dominant hand.


Reference to the back or upper aspect of the body. On occasion it refers to the thoracic spine.

Double Crush Syndrome

A nerve entrapment at two or more places along a nerve. Most typically the diagnosis refers to a carpal tunnel syndrome, cubital tunnel syndrome, and/or ulnar neuropathy nerve compression at the elbow, co-existing with pressure on the spinal nerve in the neck, causing numbness or tingling, muscle weakness or loss of reflex in the arm or hand.


The outermost, toughest, fibrosis layer covering of the brain, spinal cord and nerve roots. It also holds the brain in place and contains the cerebral spinal fluid.

Dural impingement

Pressure or deformation of the dura caused by bulging disc, bone spurs, or thickened ligaments.


A device which measures grip strength.


An abnormal sensation that a patient reports as uncomfortable that may include burning, tingling, numbness, or “pins and needles.”


A chronic depressed mood lasting more than two years.



Edema refers to any collection of fluid, seen as swelling, that is outside of blood vessels or organs – usually collecting within the connective tissues that support our organs or muscles.


Electromyogram or Electromyelogram. A test to evaluate the motor function of the peripheral nerves and the related spinal nerves. The test involves use of a needle to test nerve conduction speed. The method of the EMG is to insert small needles in muscle groups and observe for electrical indications of denervation or loss of nerve function.

Empty can test

A clinical test used by physicians to look for rotator cuff pathology in the shoulder.  It is used to identify injury of the supraspinatus.  The test is done with your arms extended out in front of you with your thumbs pointing to the ground as if you were emptying a can.  The doctor asks you to resist as he attempts to push you arms to your side.  A positive test is noted if this maneuver produces pain in the shoulder.

End feel

The quality of the resistance to movement that the health care provider feels when testing the range of motion end point of a particular joint.

Epidural block

The injection of anesthetic into the epidural space in order to block or desensitize a specific nerve at particular points of a nerve pathway.

Epidural space

The space outside the dura of the brain and spinal cord. The dura is the outer membrane covering the spinal cord and the brain.

Epidural steroid injection

The injection of a potent anti-inflammation drug into the epidural space around the nerve or joint for therapeutic purposes. It is used to decrease inflammation in the spinal space and spinal nerves and reduce pain.


A movement that brings two parts of a joint toward a straight position. In the lumbar spine, this is starting in a forward bent position and returning to a straight position (the neutral or standing position) or bending backwards from the neutral position. In the cervical spine the term is used to refer to the movement involved in looking-up or starting in a forward bent position and returning to a straight position.

Extradural defect

Indentation of the thecal sac or dura by disc bulge, osteophyte, defect in the bone, ligament, cyst or tumor. This terminology is often used by radiologists noting abnormalities on imaging studies.

Extruded disc

See Herniated Disc.