abduction A movement of a body part away from the midline of the body.
accident An act that occurs by chance or without intention.
acne vulgaris Infected hair follicles and sebaceous glands.
acute injury An injury with sudden onset and short duration.
ad libitum In the amount desired.
adduction A movement of a body part toward the midline of the body.
Affordable Care Act Mandates the availability of affordable health care insurance for every American.
agonist muscles Muscles directly engaged in contraction as related to muscles that relax at the same time.
ambulation Moving or walking from place to place.
amenorrhea Absence or suppression of menstruation.
amnesia Loss of memory.
analgesia Pain inhibition.
anaphylaxis An immediate transient allergic reaction resulting in swelling of tissues and dilation of capillaries.
anemia Lack of iron.
anesthesia Partial or complete loss of sensation.
angioedema A well-defined area of swelling, occurring as a result of an allergic response.
anorexia Lack or loss of appetite; aversion to food.
anorexia nervosa Eating disorder characterized by a distorted body image.
anoxia Lack of oxygen.
antagonist muscles Muscles that counteract the action of the agonist muscles.
anterior Before or in front of.
anterior cruciate ligament Ligament that stops external rotation.
anxiety A feeling of uncertainty or apprehension.
apophysis A bone outgrowth to which muscles attach.
arrhythmia Irregular movement.
arthroscopic examination Viewing the inside of a joint via the arthroscope, which utilizes a small camera lens.
articulation A joint.
assumption of risk The individual, through expressed or implied agreement, assumes some risk or danger will be involved in a particular undertaking.
asymmetries (body) A lack of symmetry of sides of the body.
ATC An athletic trainer certified by the Board of Certification.
atrophy Wasting away of tissue or of an organ; diminution of the size of a body part.
avascular necrosis Death of tissue resulting from a lack of blood supply.
avulsion A tearing away.
axial loading A blow to the top of the athlete’s head while in flexion.
axilla Armpit.