acclimation The process of adjusting physiologically or psychologically to different environmental conditions, such as altitude or temperature

acetabular labrum A ring of fibrous cartilage that runs along the socket of the hip joint

acetabulum The socket of the hipbone in which the head of the femur rests, forming a ball-and-socket joint

achondroplasia The most common form of dwarfism, a genetic disorder that affects the development and maturation of bone from cartilage

acromioclavicular (AC) joint The joint located at the top of the shoulder between the acromion and the clavicle

actinic conjunctivitis An eye disease characterized by inflammation of the conjunctiva due to prolonged exposure to ultraviolet light

acute fracture Break of bone or cartilage in which the fracture line is sharp and the surrounding bone appears normal

acute injury An injury that occurs with a rapid onset after a single event

adhesion Fibrous band of scar tissue that forms between tissues not normally bound together, often resulting from injury

agonist A contracting muscle that is resisted by an antagonist muscle

air embolism Any obstruction of the circulatory system caused by the entry of air bubbles into the bloodstream, often through ruptured alveoli

all-around development The emphasis on the development of the three primary attributes of athleticism, flexibility, and musculoskeletal and cardiovascular capacities

allograft The surgical transplant of tissues or organs between different individuals of the same species

ALPSA (anterior labral periosteal sleeve avulsion) A lesion at the distal end of the shoulder associated with shoulder dislocation

alternative medicine Healing practices that fall outside the realm of conventional medical practice, such as homeopathy, acupuncture, naturopathy, or herbalism

alveoli Tiny air sacs within the lungs that facilitate the exchange of carbon dioxide and oxygen; the terminal points of the airways within the lungs

amenorrhea The absence or abnormal cessation of a menstrual period in a premenopausal female when menstruation should be present

anabolic-androgenic steroid A synthetic drug that is used to stimulate muscle and bone growth by mimicking the male hormone testosterone

anaerobic threshold The point during exercise when the body begins to work the muscles without the use of oxygen; the limit at which aerobic exercise can be maintained

aneurysm An abnormal blood-filled swelling of an artery or vein from weakness of the blood vessel wall

ankle inversion test A range-of-motion test performed on the ankle; positive tests reveal a potential tear of the calcaneofibular ligament of the ankle

annular ligament A strong band of fiber that surrounds the wrist or ankle joint

anomalous coronary arteries Congenital variation in the origin, pathway, termination, number, or structure of the coronary arteries; most anomalies are clinically silent and do not affect quality of life

anorexia athletica A condition in which people engage in excessive exercise to lose weight, typically associated with anorexia nervosa

anorexia nervosa A condition in which people intentionally starve themselves for fear of gaining weight, usually characterized by extremely low body weight and body image distortion

antagonist The counterpart of the contracting, or agonist, muscle responsible for the lengthening or stretching of the agonist

anterior apprehension test A clinical test for assessing the instability of a shoulder, in which apprehension with abduction and external rotation of the joint suggests anterior instability

anterior drawer test A measure of the stability and integrity of the anterior cruciate ligament of the knee

aortic stenosis A cardiovascular disease characterized by the abnormal narrowing of the aortic valve between the left ventricle and the aorta

Apley grind test A commonly applied diagnostic test in which the physician grips the hand of the patient and applies downward pressure, causing the hand to deviate toward the ulna

Apley scratch test A clinical test used to assess the range of motion of the shoulders by asking the patient to scratch his or her back

Apley test A clinical test used to assess knee or shoulder injuries

apophysis A natural swelling or outgrowth, or protuberance, on any part of a bone

apophysitis An inflammation of an apophysis

apprehension test A clinical test used to assess the location and severity of injuries, which is performed by manipulating a patient's joints and gauging his or her pain response

arachnoid mater The weblike protective covering of the brain and spinal cord; the middle of the three layers of meninges

arrhythmogenic right ventricular dysplasia A genetic disorder of the heart that is characterized by abnormal, arrhythmic ventricular contractions

arteriovenous malformation A congenital disorder characterized by an abnormal connection of veins and arteries, often resulting in internal bleeding and headaches

arthrofibrosis A condition most often associated with the knee, characterized by the growth of scar tissue resulting in limited joint mobility

arthroscopic portal Small incision through which arthroscopic surgery is performed

arthroscopy A minimally invasive surgery that allows the physician to examine the interior of a joint and diagnose and treat common knee, shoulder, and other joint problems

articular (hyaline) cartilage A tough, fibrous connective tissue that forms on the surface of bones within joints and aids in joint mobility

aseptic necrosis A condition in which the lack of blood supply to the bone may cause bone tissue death

ataxia The lack of motor coordination or the inability to coordinate skeletal muscle contractions

athlete's heart syndrome A medical condition in which the heart enlarges in response to the physiologic stresses of strenuous physical training; typically benign but difficult to distinguish from more serious cardiovascular illnesses

athlete's nodules A general term for relatively hard, discrete, roughly spherical, abnormal cutaneous masses occurring in individuals who engage in sports

athletic pseudonephritis The occurrence of protein and white and red blood cells in the urine in response to strenuous physical activity, often mimicking the problems associated with kidney disease but clearing up completely after 3 days of rest

atlantoaxial instability Increased flexibility of the ligaments between the atlas and the axis, the two bones at the top of the spinal column, with neurologic symptoms occurring when the spinal cord is affected

atlas (vertebra) The uppermost cervical vertebra of the spine

atopy An allergic reaction that becomes apparent almost immediately in response to a stimulus; genetically determined hypersensitivity to an allergen

ATP (adenosine triphosphate) A complex chemical compound derived from adenosine that is formed by the energy released from food and is used to perform cellular metabolic functions; energy molecule of a cell

auditory exostosis Benign bony growth located in the external auditory canal; frequently present in athletes who engage in water sports

autograft Tissue that is taken from one site and grafted onto another in the body of the same individual

avascular necrosis Death of the cells in a bone or joint due to depletion of blood supply

avulsion A painful separation of a muscle from its attachment to a bone

avulsion fracture Bone fracture that occurs when a tendon pulls off a piece of bone from a larger bone mass, usually as a result of a violent or forceful muscle contraction

axial compression test A test performed by pressing on the top of the patient's head with his or her neck in a neutral position; test is positive if the pain is aggravated

axial pain (syndrome) Pain referring to the central part of the body; back pain distinguished from the limbs

axis The second uppermost cervical vertebra, which provides a pivot for turning the head

axon A long extension of a neuron responsible for conducting a signal away from the cell body

balance The capacity to remain in a controlled position without falling or losing coordination

Bankart lesion A tear of the anterior glenoid labrum that is caused by violent movement of the arm

Basilar skull fracture Fracture that occurs at the base of the skull or the portion underneath the brain

belly press test A clinical test used to assess the function of one of the four muscles of the rotator cuff located within the shoulder, the subscapularis; performed with the patient in a standing position with his or her hand on the stomach, pushing as hard as possible

Bennett fracture A bone fracture of the first metacarpal between the thumb and wrist

bipartite Consists of two parts or divisions

Blount disease A growth disorder of the tibia in which the lower leg angles inward; characterized by a bow-shaped lower leg

bony Bankart lesion A fracture of the front lower portion of the glenoid; see Bankart lesion

bony edema A swelling of a bone that occurs following an injury

boutonniere deformity A deformity of the finger in which the joint nearest to the knuckle is bent inward due to misalignment of the tendons

bowlegs Legs that bend outward instead of angling inward; the opposite of knock-knees

boxer's fracture A fracture in the fourth or fifth metacarpal, which comprises the knuckles

brachial plexus An arrangement of nerves that conducts signals from the spine to the shoulder and allows for movement of the arm

bronchitis A respiratory disorder characterized by inflammation of the mucus membranes lining the bronchial tubes

bronchoconstriction Constriction of the bronchioles (airways in the lungs) due to the tightening of surrounding smooth muscle; can cause coughing, wheezing, and shortness of breath

bulge Swelling or outward protrusion

bulimia nervosa An eating disorder characterized by episodes of binge eating followed by behaviors designed to prevent weight gain, such as purging, fasting, or excessive exercise

bursa(pl., bursae) A small, fluid-filled sac that provides a cushion between bones and tendons and/or muscles around a joint. Aids in reducing friction between bones and allows free movement

bursitis Painful inflammation of a bursa caused by pressure, repetitive stress from overuse, or infection

cam impingement An abnormal shape of the proximal femoral epiphysis that causes the femoral head to fit awkwardly within the socket, resulting in mild to severe pain

capsulorrhaphy arthropathy A disease afflicting the shoulder characterized by deterioration of the joint surface due to previous repairs of recurrent dislocations

cardiovascular drift A phenomenon that describes an increase in heart rate with prolonged exercise (greater than 10 minutes) despite the exercise continuing at the same intensity

catharsis In psychiatry, the process of release of repressed memories, ideas, or emotional tension

cauda equina syndrome A serious neurological condition characterized by a dull pain and numbness in the buttocks, genitals, and/or thigh with uncontrolled bladder and bowel function due to compression of the spinal nerves

central nervous system The part of the nervous system consisting of the brain and spinal cord; responsible for integrating environmental signals

cerebral edema An excess accumulation of fluid in the intracellular and extracellular spaces of the brain; a serious condition requiring emergency treatment

cerebrospinal fluid The fluid surrounding the brain and spinal cord that protects the spinal cord and provides nutrients

cervical spine The part of the vertebral column comprising the first seven vertebrae inferior to the skull

chair sign A clinical test to check for elbow stability and integrity, in which the patient is seated with elbows flexed at 90°, with forearms supinated and arms abducted, and then tries to rise from the chair pushing down only with the arms

chiropractic An alternative or complementary medical system that focuses on maintaining correct alignment of the musculoskeletal system; spinal manipulation is the most common treatment method, and many people visit chiropractors for treatment of low back pain

chondrolysis Disappearance of the cartilage on the joint surface of the femur (articular cartilage) as a result of disintegration or dissolution

chondromalacia A degeneration or softening of the articular cartilage

chondromalacia patella A softening of the cartilage on the articular surface of the patella that causes pain, particularly during flexion

chondroplasty The smoothing of torn cartilage on the joint surface

chronic exertional compartment syndrome An exercise-induced neuromuscular condition that causes swelling and pain in the arms and legs

closed fracture A fracture that does not pierce the skin

coarctation of the aorta A congenital disorder characterized by narrowing of the aorta, thereby decreasing blood flow to the body

coccyx The end of the spinal column; the base of the spine where the vertebrae are fused

co-contraction A type of contraction when both agonist and antagonist muscles fire at the same time

Colles fracture A fracture to the distal end of the radius bone located in the forearm

comminuted fracture A fracture involving extensive fragmentation of bone

commotio cordis Sudden heart failure due to a severe blow to the chest; most common in extreme contact sports

compartment A group of related muscles found in the same area of the body

compartment syndrome An acute medical issue characterized by the overuse of the same muscle or muscle group and decreased blood flow in a confined anatomical space

complementary medicine A diverse set of systems of holistic medicine based on philosophies other than those used in conventional Western medicine; often called preventive medicine

compound fracture The former term for a broken bone that has gone through the skin; now called open fracture

concentric movement The part of the movement where the agonist muscle contracts, for example, the lifting motion of an exercise

concussion An injury to the brain caused by a violent blow or rapid shaking; a mild concussion may involve no loss of consciousness; severe concussion may cause prolonged unconsciousness. An athlete who has had a concussion should return to play only with a physician's approval

conditioning Development of physical fitness through adaptation of the body and its various systems to a program of exercise

conduction The act of transmitting heat, sound, or nervous impulses from one area of the body to another

condyle A rounded epiphysis of a bone usually encased in the articular cartilage

contralateral Of or relating to the opposite side

contusion A blunt force injury that does not break the skin but causes underlying tissue damage, with bleeding under the skin (bruising)

convection The transfer of heat via gas or liquid

coordination The ability to conduct more than one set of muscle movements in unison

coracoid The bony prominence of the scapula

costochondritis An inflammation at the point where the ribs fuse with the sternum

crepitus A grinding noise or sensation within a joint or the lungs

cruciate Cross-shaped

crutch palsy Compressive injury to the nerve complex (the brachial plexus) located in the underarm

cyanosis A medical condition characterized by a bluish discoloration of the skin or mucous membranes; a symptom that indicates a dangerously low level of oxygen in the discolored area

de Quervain diseaseSee de Quervain tenosynovitis

de Quervain tenosynovitis A painful inflammation of the tunnel that surrounds the two tendons that control the movement of the thumb

debridement Surgical removal of dead, damaged, or infected tissue and foreign matter from a wound or burn

deep vein thrombophlebitis The formation of a blood clot within a vein, typically located in the leg; causes the extremity to become swollen, painful, red, and/or warm

dehydration An excessive deficiency of body water

dens A superior projection of the vertebral body that goes up into the anterior ring of the atlas

depressed skull fracture A skull fracture in which fragmented bones press into brain tissue and cause neurological trauma

dermatophyte A parasitic fungus that infects the skin

dermis The deep vascular layer of the skin located beneath the epidermis

diabetes mellitus A condition characterized by hyperglycemia, resulting from the inability to appropriately control blood sugar and regulate insulin levels

diaphragm A muscular partition between the thoracic and abdominal cavities that regulates breathing

diaphragmatic breathing The act of breathing deep within the lungs by focusing on lowering the diaphragm rather than expanding the chest

diaphysis The main shaft of a long bone

diastatic skull fracture Fracture that occurs along the growth plates or sutures of the skull

disability A physical or mental impairment that prevents a person from performing one or more major life activities

disk herniation A condition of the vertebral column in which a tear in the outer, fibrous ring (nucleus pulposus) of an intervertebral disk allows the soft, central portion (anulus fibrosus) to bulge out, commonly known as a slipped disk

disk-osteophyte complex A medical condition where the soft tissue of the intervertebral disk extrudes beyond its normal parameters

displaced Pertaining to the removal from the normal position, location, or place

distraction test An orthopedic test performed on the knee; positive tests indicate a ligamentous injury of the knee

diuretic Any substance that increases the amount of urine production by the kidneys and reduces the amount of water in the blood, thereby decreasing the blood volume

dorsal Pertaining to the back surface of a body part, such as the backside (knuckle side) of the wrist and hand

dorsiflexion Backward flexion or bending toward the dorsal side; flexing the ankle and pointing the toes upward

drawer test An orthopedic test that is used to detect torn cruciate ligaments in the knee

duraSee dura mater

dura mater The outermost layer of the meninges, the membranes surrounding the brain and spinal cord

dysesthesia A condition characterized by an unpleasant, abnormal sensation such as burning, caused by lesions of the nervous system

eccentric contraction A condition that occurs when the force generated by the muscle cannot overcome the resistance placed on the muscle; also, a lengthening contraction of the muscle

eccentric movement A movement in which the agonist muscle elongates

ecchymosis The escape of blood within subcutaneous tissue that results in discoloration or bruising

echocardiogram A sonar imaging scan used to study the structure and motions of the heart

edema A swelling of tissue due to the accumulation of excess fluid

effusion The discharge or outpouring of a fluid into a body cavity

electrocardiogram A medical record that is used to measure the electrical rhythms of the heart

endogenous Produced, occurring, or caused by factors within the body of an object or organism

endotenon A thin retinacular structure investing each tendon fiber

endurance The ability to withstand stress and hardship or sustain an activity over time; a measure of stamina

epicondyle A protrusion of a bone above the condyle that provides the surface area to which ligaments and tendons can attach

epidermis The outermost layer of the skin surface of vertebrates, which is on top of the dermis

epidural space The space between the dura mater and the lining of the spinal canal

epiphysis The rounded end of a long bone

epitenon A component that surrounds the tendon and contains the vascular, lymphatic, and nerve supply and is in turn surrounded superficially by the paratenon

erythema An abnormal red discoloration of the skin due to the dilation of cutaneous blood vessels

euhydration A normal state of body water content

evaporative heat loss The loss of body heat due to the evaporation of sweat from the body

excision Surgical removal of a portion or all of an organ or other structure

exercise-associated hyponatremia Dangerously low levels of sodium within the blood due to excessive exercise

exercise-induced hematuria The presence of blood within the urine due to excessive exercise

exogenous Produced, occurring, or caused by factors outside the body of an object or organism

extra-axial hemorrhage Blood loss within the intracranial space; increases pressure, causing headaches

extreme-risk injury Injury needing immediate medical attention

extrusion A bulge or protuberance, pushing out

facet joints Small joints located between adjacent vertebrae

fascia A continuous sheet of connective tissue that separates and bonds together muscles and other organs

fasciotomy A surgical procedure in which fascia is removed from the body to relieve tension and pressure

female athlete triad A medical condition seen in some female athletes, characterized by disordered eating, amenorrhea, and osteoporosis

FEV1 (forced expiratory volume in 1 second) The volume of air an athlete can expel in the first second of a forced expiration; the most important parameter examined in determining airway obstruction

first-degree strain A minor strain characterized by only a few muscle fiber tears

flail chest A severe medical condition characterized by fragmentation of the ribs due to stress

flexibility The ability of a muscle or extremity to relax and yield to stretch forces

focal fibrocartilage dysplasia An uncommon, normally harmless bone lesion that causes deformity of the long bones in youth

fontanelle The gaps located between the bones of the cranium in an infant or fetus

foramen (pl., foramina) Any opening or orifice within the body

Freiberg disease An osteochondrosis affecting the metatarsals (long bones of the foot)

Freiberg sign The reproduction of pain caused by passive internal rotation of the hip with the leg in an extended position

fulcrum test By placing the left hand under the glenohumeral joint to act as a fulcrum, the apprehension test becomes a fulcrum test

functional limitation Any health problem that prevents an individual from completing a task

ganglion cyst A small, abnormal, fluid-filled sac (usually less than 2 centimeters) that develops near a joint capsule or tendon sheath

gastrocnemius soleus (calf muscle) strain A strain or tear, with the sensation of a pop being felt, due to the simultaneous stretching and active contraction of the muscle

genu valgum A medical condition characterized by an inward curvature of the legs so that the knees touch when a person is standing straight; commonly known as knock-knees

genu varum A medical condition characterized by an outward curvature of the legs; commonly called bowlegs

GLAD lesion (glenolabral articular disruption) Lesion characterized by a labral tear associated with an injury to the glenoid articular cartilage

glenohumeral joint The shoulder joint that functions as a ball-and-socket joint; composed of the glenoid socket and the humeral head

glenohumeral ligaments Three bands of connective tissue that strengthen the glenohumeral joint

glenoid Any shallow depression of a bone resembling a pit or socket

glenoid labrum A rim of articular cartilage that surrounds the margin of the glenoid cavity in the shoulder blade

glial cell Nonneuronal cell that provides nutrients and removes waste from other neural cells

glycogenolysis The process by which glycogen is broken down in the liver into individual molecules of glucose

gout A form of arthritis caused by a buildup of uric acid in the joints

gradual progressive throwing A shoulder rehabilitation technique in which throwing motions help stabilize the shoulder

gray matter A large component of the central nervous system comprising glial cells, neuronal cell bodies, dendrites, axons, and capillaries

grind test A clinical test used to determine the integrity and problems associated with the meniscus of the knee

Hawkins-Kennedy test A test that attempts to cause external compression of the rotator cuff and consequently re-create the patient's pain

hemarthrosis Bleeding into joint spaces

hematocrit The volume percentage of red blood cells in a blood sample

hematoma Swelling formed by excess accumulation of blood

hematopoiesis The production of blood cells

hemorrhage A copious discharge of blood from the blood vessels

hemothorax Accumulation of blood located within the pleural cavity, or the area surrounding the lungs

hepatitis Inflammation of the liver caused by certain viruses or other factors such as alcohol abuse or medications

hepatomegaly Abnormal enlargement of the liver

heterotopic bone formation/ossification The formation of bone in abnormal locations, such as in soft tissue or muscle

Hill-Sachs lesion A depression in the head of the humeral epiphysis due to a forceful impact against the glenoid rim

hip dysplasia An abnormal formation and deterioration of the hip socket that is characterized by excessive pain and arthritis

hip impingement A condition that is characterized by excessive friction within the ball-and-socket hip joint

hip quadrant test A clinical test that indicates arthritis, avascular necrosis, and/or an osteochondral defect within the hip

Homans sign A sign of deep vein thrombosis; is positive when pain is located within the calf muscles

hop test A clinical test used to measure the horizontal and vertical power of the legs by performing three consecutive jumps

hydrogenation A form of chemical reduction, a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst; commonly employed to reduce or saturate organic compounds

hyperpronation The extreme inward rotation of the foot during gait

hyperalgesia An increased response to pain caused by damage to the peripheral nerves

hyperesthesia A state of abnormal increase in sensitivity to sensory stimuli

hyperlipidemia An excess quantity of lipids in the blood

hypertrophic cardiomyopathy A condition where the heart muscle becomes abnormally enlarged, limiting the amount of blood that can enter the heart and thereby reducing pumping ability

hyphema A collection of blood in the anterior chamber of the eye often caused by trauma; causes blurry vision, pain, and tearing

hypodermis The lowermost subcutaneous level of the three skin layers

hypohydrationSee dehydration

hypothalamus The part of the brain responsible for the control of endocrine glands and the autonomic nervous system

hypoxia Decreased availability of oxygen to body tissues

iatrogenic Describing inadvertent harmful consequences or complications resulting from medical treatment

idiopathic A disease of an unknown origin

iliotibial band A band of fascia that spans from the iliac crest of the pelvis region to the knee joint; can become inflamed due to excessive running

impingement Striking or excessive pressure on a tissue, often from encroachment by adjacent structures

infective endocarditis An inflammation of the membrane that lines the cavities of the heart and forms part of the heart valves, generally caused by an infection

influenza An acute, highly contagious viral disease; also referred to as the flu

inguinal hernia A protrusion of the intestines through the inguinal canal where the flesh of the abdomen meets the thigh

injury, catastrophic An extremely serious injury that may result in disability and loss of bodily functions, with full recovery doubtful

injury, nonfatal A broad range of types of injury from acute to catastrophic with no life-threatening issues

injury, serious An injury in which mortality is probable

integrative medicine A combination of alternative and conventional medicine to provide a more comprehensive healing plan for the patient

intersection syndrome Inflammation of the crossover area where the musculotendinous junctions of the first dorsal compartment meet with the tendons of the second dorsal wrist compartments

interval training An exercise strategy in which an athlete raises his or her exercise intensity above the anaerobic threshold for a short period of time and then dips back below the threshold and keeps exercising

intervertebral disk A fibrocartilaginous disk that provides cushion and support between two adjacent vertebrae

intervertebral foramen An opening between vertebrae that transmits nerves from the spine throughout the body

intraarticular dilation An expansion within the joint

intra-axial hemorrhage A hemorrhage that takes place within the central part of the body

iontophoresis Therapy that uses small electric currents to deliver medicine into tissues of the body

ipsilateral Positioned on or affecting the same side

irrigation Cleansing injured tissue by rinsing with sterile saline, with or without antibiotics in the solution

ischemic necrosis A condition in which the lack of blood supply to the bone may cause bone tissue death

isometric contraction A contraction that generates muscle force but in which no joint movement occurs, such as holding a squat for 10 seconds

isotonic contraction A contraction that occurs when the muscle contracts and joint movement occurs

jerk test A clinical test used to determine the integrity of the knee joint (possible torn meniscus), also called Hughston's jerk test, to distinguish from the simple knee-jerk test of neurological reflex by tapping the patellar tendon.

Jobe's empty can test A clinical test used to determine the integrity of the supraspinatus tendon

joint aspiration The removal of fluid from within a joint

joint effusion The escape of intraarticular fluid

joint integrity A measure of the stability and durability of a joint

joint of Luschka Small synovial joints between adjacent lower-cervical vertebral bodies—a frequent site of arthritis formation

Jones fracture A fracture of the fifth metatarsal of the foot

knock-knees A condition in which the legs curve inward at the knees; see genu valgum

kyphosis An abnormal backward curve in the spinal column

labrum A thickened portion of connective tissue that surrounds the sockets of the shoulder and hip joints

Lachman test A test that is used for examining the integrity of the anterior cruciate ligament of the knee

lactate threshold The point at which lactic acid buildup in the muscles begins to impair performance

lamina(pl., laminae) A broad plate which extends from the pedicle to the median line of the vertebra, two laminae fusing to complete the roof of the vertebral arch

laminectomy Surgical removal of any part of the lamina

lateral epicondylitis A painful inflammation of the tendon that wraps around the elbow; also called tennis elbow

lateral pivot-shift test A clinical test used to evaluate the anterolateral structures of the knee

lift-off test A clinical test used to check the stability of the shoulder

ligaments Fibrous connective tissues responsible for connecting bones, cartilage, and other structures

linear fracture A fracture that runs parallel to the axis of the bone

load and shift test An orthopedic test used to check for the stability and integrity of the shoulder

loose body A free-floating piece of bone or cartilage that has broken away and is moving around a joint

lordosis An inward forward curve of the lower spine

lucid interval A temporary improvement in a patient's condition following a traumatic brain injury, after which the patient's condition deteriorates

Ludloff sign A test checking the ability to flex the thigh while sitting down; is positive if patients fail to perform the test, and negative if performed effectively

lumbar The portion of the spinal column between the thorax and the pelvis, commonly called the lower back

luteal phase The second half of the menstrual cycle lasting from ovulation to menstruation

malleolar bursitis Swelling and pain over the ankle bone caused by irritation of the bursa, a fluid-filled sac that aids in reducing friction between moving bones

McMurray test A test used to determine whether a meniscal tear is present in the knee by bending the lower leg, straightening it out, and rotating it; is positive if pain is found around the area of the meniscus

medial and lateral patellar glide test A test used to determine the stability of the lateral retinaculum in the knee and the medial aspect of the knee

medial epicondylitis An overuse injury, commonly known as golfer's elbow, that causes pain in the inside of the elbow

medial tibial stress syndrome An overuse injury, commonly known as shin splints, causing irritation in the shinbone, which is located in the front of the lower leg

mediastinum The central cavity surrounded by the lungs, containing the heart, proximal aorta, and vena cava and lined by a protective tissue, the pericardium

meninges Protective coverings of the brain and spinal cord, consisting of three layers from outermost to innermost—namely, the dura mater, arachnoid, and pia mater

meniscal cartilage The cushioning tissue of the knee between the femur and the tibia

meniscus A structure consisting of both the lateral and the medial cartilage of the knee, acting as a pad between the joints of the femur and the tibia and providing a smooth surface for the joints to glide on

menorrhagia Excessive menstruation that lasts for more than 7 days

metabolic ketoacidosis A condition that usually affects patients with diabetes when the body has very low levels of insulin and starts to break down body fat, leading to the formation of a high concentration of ketone bodies, and thus causing the blood to become too acidic

metaphysics The study of reality in relation to such questions that may not be answered scientifically; also, the study of subjects relating to mind and matter

metatarsalgia An overuse injury that causes pain in the middle region of the forefoot

microfracture A surgical technique in which tiny holes are made in the exposed bone in an area of the joint where the full thickness of the cartilage has been completely damaged

microtrauma The term given to microscopic injuries such as microtears in muscles, tendons, and tissues

milk test An orthopedic measure to test elbow instability

Monteggia fracture A break in the ulna bone of the forearm, along with dislocation of the radial head

Morton neuroma Irritation, pain, and swelling of the nerve located between the third and fourth toes of the foot

moving valgus stress test A test used to determine whether the medial collateral ligament (MCL) of the elbow is torn

MR (magnetic resonance) arthrogram A test used to examine the joints in the body, such as the knee or shoulder, in which a contrast-enhancing dye is injected to facilitate viewing by magnetic resonance imaging

muscle hypertrophy The increased cross-sectional size of the muscle fibers

muscle strength The ability of the muscle to create force against physical objects

muscular endurance The ability of a muscle to perform and maintain repeated muscle contractions over long periods of time

myocarditis An inflammation of the heart muscle (myocardium)

myocardium Cardiac muscles that make up the bulk of the heart wall

myofascial release The adding of pressure with the thumb over the muscle spasm to decrease the contraction

myositis ossificans The formation of bone within muscle tissue; occurs after the tissues surrounding the muscles are damaged in a traumatic injury

Neer test A test that attempts to cause external compression of the rotator cuff and consequently recreate the patient's pain

nerve impingement (or “pinching” of the nerve) Refers to pain in or impaired function of a nerve that is under pressure

nerve root A part of a collection of nerve fibers that branch off from the spinal cord. Dorsal roots are composed of sensory fibers that bring information into the spinal cord. Ventral roots are composed of motor neurons that carry commands from the spinal cord to the muscles and internal organs

nerve tracts A collection of nerve fibers located in the central nervous system (CNS)

neurons Nerve cells; the conducting cells of the nervous system that receive and transmit information through chemical and electrical signals

Noble compression test A test used to check for iliotibial band syndrome

nondisplaced A type of fracture in which the bone maintains its normal alignment after breaking

nonpurging-type bulimia nervosa An eating disorder involving excessive eating along with attempts to compensate afterward through diet pills, fasting, or excessive exercise

nonunion A fractured bone that failed to heal properly

nuchal ridge A thick crest located on the back of the neck and base of the skull (occipital bone)

nucleus pulposus A gelatinous substance found in the center of intervertebral disks of the spinal column; aids in shock absorption

Ober test A test used to evaluate the shortening of the iliotibial tract muscle

O'Brien test A test used to evaluate acromioclavicular joint injury in the shoulder

OCDSee osteochondritis dissecans

occipitocervical injuries An injury of the cervical spine in which the cranium dislocates from the neck, a severe injury that can be fatal if not treated immediately

odontoid process A toothlike structure found in the second vertebra of the neck

open fracture A fracture in which the bone penetrates through the skin, also called a compound fracture

orthorexia nervosa An eating disorder characterized by an excessive concern with eating healthy foods (not officially recognized as a medical diagnosis)

orthosis A support device used to brace or correct the function of specific limbs—for example, arch supports that are used to correct foot function

os acromiale Pain in the shoulder due to the failed fusion of the bone at the front of the shoulder roof known as the acromion

os odontoideum A separation of the top of the dens from the C2 vertebral body

ossicle The smallest bones in the body, of which three are located in the middle ear

osteoarthritis A form of arthritis; a degenerative disease that affects joints and also leads to the gradual breakdown of cartilage and the formation of “bone spurs” on joints

osteoblasts Cells in the body that are responsible for bone formation

osteochondral injury An injury that affects the articular cartilage and the bone underneath

osteochondritis Inflammation of bone and cartilage

osteochondritis dissecans (OCD) An injury in which fragments of cartilage and bone are separated from the end of the bone and are loose in the joint space

osteochondrosis The necrosis or breakdown of growth centers in the pediatric or skeletally immature patient followed by regeneration or healing

osteoclast A body cell that not only breaks down bone tissue but also absorbs it back into the body

osteolysis The active resorption of bone matrix by osteoclasts as part of an ongoing disease process

osteonecrosis A condition in which the lack of blood supply to the bone may cause bone tissue death

osteopenia A condition in which the level of bone mineral density is below normal levels, but not as severe as in osteoporosis

osteophyte An abnormal growth of bone in damaged joint areas, more commonly known as a bone spur; commonly seen in osteoarthritis due to the nature of degenerative joints

osteoporosis A disease that causes bones to lose density, strength, and tissue over a period of time, leaving bones fragile and more susceptible to injuries such as fractures

osteotomy A surgical procedure that involves cutting the bone to promote proper alignment and healing in the affected joint area; can be used for arthritis treatment and to fix bones that may have grown incorrectly

otalgia Ear pain, of which there are two types: (1) pain originating from the outside of the ear, or referred otalgia, and (2) pain that originates from within the ear, or primary otalgia

otorrhea A discharge of fluid from the ear canal

Ottawa ankle rules A set of guidelines established to help physicians determine whether X-rays are needed to diagnose possible fractures in the foot or ankle

Ottawa knee rules A set of guidelines established to help physicians determine whether X-rays are needed to diagnose knee injuries

outer annulus The outermost layer of fibrocartilage in an intervertebral disk, tears or ruptures of which may permit extrusion of the nucleus pulposus into the surrounding tissue

overreaching A condition in which an athlete trains excessively, causing stress, fatigue, and sometimes poor athletic performance

Pace sign A test used to determine whether a patient has piriformis syndrome, a compression of the sciatic nerve by the piriformis muscle of the thigh

paraplegia Partial or complete paralysis of the lower extremities caused by a spinal cord defect or traumatic injury

paratenon The external covering of the entire tendon

paratenonitis Inflammation of the paratenon, the outermost layer of the tendon

paresthesias The occurrence of abnormal nerve sensations such as tingling, burning, itching, and “pins and needles,” sometimes caused by nerve damage

parietal pleura A specialized skinlike surface that lines the thoracic cavity

patellar tendinosis Inflammation or long-term damage to the tendon that connects the bottom of the kneecap to the top of the shinbone

patellar tendon The attachment of the quadriceps muscle to the tibia

patellar tilt test A test used to assess the tightness of the lateral side of the knee and also pain around the kneecap (patella)

Pavlik harness A soft brace used for babies less than 6 months old with thighbone fractures

periodization The process of splitting up time into blocks; in sports medicine, the splitting up of a training regimen into phases

periosteum A membrane/tissue covering all bones

peripheral nervous system Composed of the nerves outside the brain and spinal cord, which also connect the central nervous system to the sensory organs, limbs, and muscles

pertussis A contagious bacterial disease that causes violent coughing, commonly known as whooping cough

pes planus A condition in which the arch of the foot collapses and touches the ground, commonly called flat feet

petechiae Round red spots that are visible on the skin due to bleeding under the skin

phalanges(sing., phalanx) The bones of the fingers and toes

pharmacokinetics The study of what happens to a drug after it is taken into the body, that is, how it is metabolized

phonophoresis A technique using ultrasound to help the body absorb therapeutic drugs through the skin

physiatrist A physician who specializes in physical and rehabilitation medicine

physis The growth plates at the ends of long bones

pia mater The innermost layer of the meninges, the membranes surrounding the brain and spinal cord

pincer impingement A form of hip abnormality in which the front edge of the hip socket sticks out too far

piriformis sign A test used to determine whether the pain originating in the gluteus maximus causing referred pain down the leg is due to piriformis syndrome

pivot-shift test A test used to determine the stability of the anterior cruciate ligament (ACL) in the knee

plantar fascia A series of connective tissues that start from the heel and support the arch in the foot

plantarflexion Bending of the foot in a downward direction

pleura A membrane that surrounds the lungs and also covers the diaphragm and lines the inner chest wall, forming a potential space for lung expansion

pleural cavity The body cavity that surrounds the lungs

plica syndrome An inflammation of the plica (see plicae) found in the knee

plicae Bands of synovial tissue located in the lining of a joint

plication A surgical procedure used to tighten tissues by folding them into tucks and suturing them

pneumomediastinum A pathological condition consequent to trauma to the chest in which air leaks from the injured lungs into the middle of the chest (mediastinum)

pneumonia An inflammation of the lungs caused by infection

pneumothorax A serious condition that occurs following the collapse of a lung, in which air collects in the pleural space surrounding the lungs and makes breathing difficult

popliteal Refers to the structures in the back of the knee, such as veins, nerves, arteries, and so on

positive J sign A test that shows the patella tracking laterally as the knee changes from flexion to extension

posterior drawer test A test to evaluate the posterior cruciate ligament (PCL) in the knee, especially for tears and ruptures

posterior Lachman test A test used to diagnose a torn anterior cruciate ligament (ACL)

posterior sag test A test used to determine instability in the posterior cruciate ligament

posture The position in which the body is held upright against gravity while standing or sitting down

power A force that is exerted over a period of time

progressive muscle relaxation A set of skills whereby the athlete is trained to control the tension of his or her muscles by alternatively consciously flexing them, holding the tension, and then slowly releasing them

progressive overload The increased stress placed on the body during exercise

prolotherapy A form of therapy that involves injection of a substance into the body to strengthen weakened tissues and also alleviate pain

proprioception The ability to sense the position and movement of muscles

protrusion An extension beyond the usual limits

pseudocyst An abnormal sac that resembles a true a cyst but lacks membranous lining

pterygium An abnormal growth that begins on the white of the eye and invades the cornea, the clear tissue covering the iris and the pupil, which may result from overexposure to sunlight and can be surgically removed. May also refer to a winglike triangular membrane abnormally occurring in the neck, eyes, knees, elbows, ankles, or digits

pudendal nerve compression syndrome Pain in the pelvic area due to compression activities such as cycling

pudendal nerve entrapment syndrome Chronic pain in the pelvic area due to stretching, inflammation, or compression of the pudendal nerve

pulmonary contusion Bruising of the lungs that causes pain and difficulty in breathing

pulmonary edema Excess fluid buildup in the lungs; can be caused by circulatory problems such as congestive heart failure

pulse oximetry A method in which the oxygen saturation of the hemoglobin is monitored

purging-type bulimia nervosa A type of disorder in which the bulimia patient uses vomiting, laxatives, diuretics, or enemas to rid the body of consumed calories

purpura Bleeding under the skin characterized by purple or red discoloration spots

push-up sign A test for posterolateral instability in the elbow

pyrogen A substance that causes a rise in body temperature and subsequent fever; released by certain bacterial infections

quadriceps tendon The tendon above the patella (kneecap)

radiation heat loss The loss of heat from the body, most significant between sunset and sunrise, due to infrared emission

radicular pain Muscle weakness, tingling, numbing, and pain due to the compression of a spinal nerve root

radicular symptom Pain manifested in the legs or arms due to a compressed spinal nerve root

radiculopathy The inflammation of spinal nerve roots

reduction The technique of returning a fractured bone to its proper alignment

release test A test in which a force that decreases the patient's pain is removed, causing the pain to return

relocation test A test used to determine whether anterior instability is present within the shoulder

Renee creak test A test used to diagnose pain and tightness in the iliotibial band; is positive if pain is present when standing on the affected leg with knee flexion at 30°

retromalleolar groove A concavity located in the fibula, which when abnormally shaped can lead to tearing of the peroneus brevis (PB) tendon

reversibility Reduction or complete loss of fitness as the result of not training

rheumatoid arthritis An autoimmune disorder that causes chronic inflammation in the joints and can also affect other organs in the body

rhinitis An inflammation of the mucous membrane inside the nose, commonly known as a stuffy nose, that is associated with the common cold and allergies

rhinorrhea Fluid nasal discharge; “runny nose.” Following head injury, may indicate leakage of cerebrospinal fluid, a serious condition requiring prompt medical attention

ribs, false Five ribs, located inferiorly to the true ribs, called “false” because not directly connected to the sternum

ribs, floating The lowest two sets of ribs attached to the vertebrae in the lower back

ribs, true The uppermost seven pairs of ribs, attached to the sternum

rickets A disorder that leads to the weakening and softening of bones in children; caused by lack of vitamin D and, in some cases, lack of adequate calcium intake

righting reflexes A neuromuscular response that enables the body to regain its normal position when it has been displaced

rotator cuff A structure composed of four muscles that stabilize the shoulder joint and allow shoulder movement, namely the supraspinatus, infraspinatus, teres minor, and subscapularis

sacrum The triangular bone located in the base of the spine, composed of five fused sacral vertebrae forming the rear of the pelvis

sarcopenia The degenerative loss of muscle mass and strength due to aging

second-degree strain An injury in which the muscle is overstretched, causing inflammation and pain; involves most of the muscle fibers tearing and difficulty performing certain movements

second impact syndrome A condition involving a second concussion before the first has properly healed; a serious, often fatal injury in which the brain rapidly swells up, causing an increase in the intracranial pressure

secretory phase The second half of the menstrual cycle

septal hematoma Bleeding within the nasal septum

sequestration An abnormal separation of a part from a whole, such as a portion of a bone by a pathological process or a portion of the circulating blood into the surrounding soft tissue from a broken blood vessel

Sever disease Pain in the heel due to the inflammation of the growth plate (calcaneus) located in the back of the foot

shear injury An axonal injury to the brain due to accelerated rotational forces

shoulder capsule A structure that provides extra stability to the shoulder joint

SLAP lesion (superior labrum anterior-posterior) An injury to the glenoid labrum, located in the shoulder

slipped disk A condition of the vertebral column in which a tear in the outer, fibrous ring (nucleus pulposus) of an intervertebral disk allows the soft, central portion (anulus fibrosus) to bulge out. See disk herniation

slump test A physical examination to evaluate the sciatic nerve in cases of pain in the spinal and lower extremities

Smith fracture An injury to the distal radius (forearm bone)

spasm An involuntary contraction of a muscle

specificity A measure of a test's ability to rule out a disease

Speed test A test to evaluate whether pain is present in the bicipital groove of the shoulder

spica A body casting to treat fractures

spinal stenosis A narrowing of the space enclosed by the spinal column, causing pressure on the spinal cord

spirometry A test used to measure the breathing capacity of the lungs

spondylolisthesis Forward displacement of a vertebra over a lower segment due to a congenital defect or fracture in the pars interarticularis

spondylolysis The breaking down of a vertebra, usually leading to small stress fractures from an overuse injury

spondylolytic A term used to describe a patient with a degenerative disorder of the pars interarticularis, a structure found in the vertebrae

spondylosis A degenerative disorder that affects the intervertebral disks in the spine, often referred to as spinal osteoarthritis

sports concussion A head injury caused by either mild or severe impact during sports activity that causes the brain to shake violently within the cranium

sports hernia A condition that occurs when muscles and tendon in the lower abdomen become weakened, usually causing chronic groin pain in athletes; not a true hernia

Spurling test A test for pain in the neck originating from the spinal nerve roots

Stener lesion A condition that occurs when the ulnar collateral ligament (UCL) tears and the surrounding tissue of the overlying thumb tendon gets lodged between the torn UCL fibers

stenosis A condition in which the blood vessels and tubular organs become narrowed and constricted

strain The stretching or partial tearing of the muscle, resulting in inflammation and pain

strength The ability of a muscle to generate and resist physical force

stress fracture A small crack in a bone, usually caused by overuse

stress fracture test A bone scan used to evaluate the injured area on the bone

stretch reflex A muscle contraction in response to stretching within the muscle; also known as a myotatic reflex

stroke volume The amount of blood that is pumped out of a ventricle in the heart during a contraction

structural tolerance The ability to withstand weeks or months of high-volume training without the incidence of injury, illness, or fatigue that may lead to overtraining

Stryker notch view An X-ray view used to evaluate for Hills-Sachs lesion after a dislocation

subacromial impingement Pain in the shoulder caused by friction between the rotator cuff and acromion

subarachnoid space The meningeal space located between the arachnoid and the pia mater subchondral bone A bone layer that underlies the articular cartilage

subcutaneous emphysema A pathological condition that occurs when air is trapped beneath the tissues in the skin of the chest, neck, and face

subdural space The space between the dura mater, the outermost meningeal layer, and the underlying arachnoid mater, caused by an injury or a pathologic process such as a subdural hematoma

subluxation A condition that occurs when the patella, commonly called the kneecap, becomes partially dislodged from its normal position

subtalar neutral position The normal position of the foot when one walks

sulcus sign A test to evaluate the presence of inferior instability within the glenohumeral joint

superior retinaculum The ligament binding the extensor tendons closest to the ankle joint

surfer's ear A condition that occurs when the ear canal becomes blocked due to abnormal bone growths, called exostoses, caused by prolonged exposure to cold water and wind

surfer's myelopathy A nontraumatic spinal cord injury in which blood flow to the spine is interrupted when the back is hyperextended, sometimes causing partial or complete paraplegia

swan-neck deformity A hand deformity in which the distal joint of the finger is pointed inward and the proximal joint outward

synchondrosis A cartilaginous joint that joins bone to bone, such as the sternocostal joints where the first ribs join the sternum

syncope A temporary loss of consciousness, commonly known as fainting

synostosis A condition in which two separate bones fuse together as one

synovial cyst A cyst that is filled with synovial or joint fluid to produce its characteristic bulge

synovial fluid The lubricant that serves to reduce friction of the articular cartilage within the joint capsule

synovial tendon sheath A membrane consisting of an outer fibrotic sheath and an inner synovial sheath, which may be found in areas subject to increased mechanical stress where efficient lubrication is required

synovitis An inflammation of the synovium, the tissue that lines the joints

synovium A soft tissue that lines the joints and produces synovial fluid

syringomyelia A disorder characterized by the formation of a cyst in the spinal cord

tachycardia A heart rate faster than normal

tarsal coalition A condition in which two bones in the back of the foot (tarsal bones) are fused

tendinitis The inflammation of the tendon; rarely occurs without the presence of underlying degenerative tendon change

tendinopathy Tendon injuries such as tiny tears, pain, and inflammation

tendinosis A noninflammatory repetitive injury to the tendon resulting in microtears that do not heal properly

tendon A band of fibrous connective tissues that connect a muscle to a bone

tenodesis stabilization Procedures that are indicated for patients with lateral ankle instability with failed anatomic repair; consists of a suture of the end of a tendon to a bone

tenosynovitis An inflammation of a tendon and its sheath

tenotomy A surgical procedure that involves cutting or releasing a tendon

tension pneumothorax A condition that forms a one-way valve, allowing air to enter the pleural space but not to escape; the buildup of air within the pleural space producing pressure on the lungs, thus making breathing difficult

tetraplegia A traumatic spinal injury that causes complete paralysis of all limbs

therapeutic exercise A therapy with goals such as improving musculoskeletal function, recovering from injuries, and providing relaxation

thermoregulation Control of body temperature

third-degree strain The most severe type of strain, which occurs when a muscle has been completely ruptured due to an injury

Thomas test A test used to evaluate whether a patient can extend the hips

Thompson test A test used to evaluate for an Achilles tendon rupture

thoracic kyphosis An abnormal forward curvature of the upper back region

thoracic spine The middle region of the spine, consisting of 12 vertebrae

tibia vara A growth disorder of the upper shinbone, causing a bowlegged appearance

tinea capitis A contagious infection of the scalp caused by a fungus, commonly called ringworm

tinea corporis A contagious fungal infection affecting the skin, commonly known as ringworm

tinea cruris A fungal infection affecting the groin area, commonly called jock itch

tinea pedis A fungal infection of the foot, commonly known as athlete's foot

Tinel test One of two tests used to diagnose the presence of carpal tunnel syndrome

tophi The buildup of uric acid in joints, bones, and cartilage

torticollis A pathological condition involving uncontrolled spasms of the neck muscles so that the neck remains in a twisted position with the head tilted and turned to one side

toss The act of disengaging a member of a cheerleading team from either a pyramid or a base arrangement

traction apophysitis An inflammation of an unfused apophysis caused by excessive pull of an attached tendon

training load The product of all three fundamental components of training: frequency, duration, and intensity

trans fat An unsaturated fat that is made into a solid by adding hydrogenated oils during manufacturing

Trendelenburg test A test to evaluate hip function, specifically of the gluteus medius muscle, in which the patient is asked to stand on one leg

triangular fibrocartilage complex A structure found in the wrist that is made up of several different structures, the primary components are being the dorsal and palmar volar ligaments

trochanter Two bony projections located near the end of the thighbone

trochlear groove The concave surface in the knee joint where the patella makes contact with the femur

tuberosity A protuberance on a bone, especially where a muscle or ligament is attached

turf toe Pain at the base of the great toe caused by jamming the foot

uncinate process Any hooklike process, such as that keeping a vertebra from sliding backward off the vertebra below it

uric acid A heterocyclic compound of carbon, nitrogen, oxygen, and hydrogen with the formula C5H4N4O3; a chemical created when the body breaks down substances called purines

valgus Bowlegged position

valgus stress test A test to evaluate the medial collateral ligament (MCL) in the knee

varus Knock-kneed position

varus stress test A test to evaluate the lateral collateral ligament (LCL) in the knee

vertebra(pl., vertebrae) Any of the separate segments comprising the vertebral column; there are normally 33 of them, differing in size and structure according to location

vertebral foramen The opening in the center of the vertebra through which the spinal cord passes

vesicle A small sac containing fluid

visceral pleura A membrane covering the lungs and lining the inner wall of the chest

Vo2max Refers to the peak oxygen uptake and the body's ability to use it during exercises that increase in intensity over time

volar Refers to the the palmar surface, or underside of the wrist and hand

volar plate A thick ligament found in the fingers preventing hyperextension injuries

West Point view A specially positioned X-ray view used to detect a Bankart lesion of the shoulder

white matter The portion of the brain containing myelinated nerve fibers; also part of the central nervous system

winging Lifting off of the medial border of the scapular shoulder

xerosis A condition in which the skin is abnormally dry

Yergason test A test that is conducted by having the patient flex the elbow and rotate the hand from a palm-down position to a palm-up position while the examiner resists the motion

Zanca view An X-ray view used to evaluate the acromioclavicular (AC) joint in the shoulder