Abduct - moves body segments away from the midline of the body
Anatomical position - erect standing position with all body parts, inclduing palms of the hands, facing forward; starting position for segment movements
Anteroposterior axis - imaginary lines around which frontal plane rotations occur
Axis of rotation - imaginary line perpendicular to the plane of rotation and passing through the center of rotation
Balance - ability to control equilibrium
Center of gravity - point around which a body's weight is equally balanced, no matter how the body is positioned
Curvillinear motion - motion along a curved line
Extension - movement that returns a body segment to anatomical position from a position of flexion
Externally rotate - rotating a body segment outwards (away from the midline of the body)
Flexion - anteriorly directed sagittal plane rotations of the head, trunk, upper arm, forearm, hand, and hip, and posteriorly directed sagittal plane rotation of the lower leg
Force - push or pull; the product of mass and acceleration
Frontal plane - plane in which lateral movments of the body occur
General motion - motion involving translation and rotation simultaneously
Horizontal trajectory - projection of an object upwards at a slight angle that follows a flat, long shape
Linear velocity - the rate of change in velocity
Mediolateral axis - imaginary line around which sagittal plane movements occur
Moment of inertia - inertial property for rotating bodies representing resistance to angular accelerations; based on mass and distance the mass is distributed from the axis of rotation
Projectile - a body in free fall is subject only to the forces of gravity and air resistance
Pronate - combined conditions of dorsiflexion,eversion, and abduction (ex. wrist = turn so palms face down)
Radius of rotation - distance from axis of rotation to a point of interest on a rotating body
Range of motion - angle through which a joint moves from anatomical position to the extreme limit of segment motion in a particular direction
Rotation - circular movement of an object around an axis
Sagittal plane - plane in which forward and backward movements of the body occur
Stability - resistanc to disruption of equilibrium
Transverse plane - plane in which horizontal body segment movements occur when the body is in an erect standing position
