Untitled Flashcards Set

System: Any structure or organization of related structures whose state of motion is of analytical interest.

Anthropometry: The discipline that studies measurements of the body and body segments in terms of height, weight, volume, length, breadth, proportion, inertia, and other properties related to shape, mass, and mass distribution.

Body mass index (BMI): Ratio of body mass to height used to describe stature.

Ponderal index (PI): Ratio used to describe stature.

Somatotyping: System of body-type description based on weight and muscularity relative to height.

Ectomorphic: Somatotype described as being linear and relatively thin for height.

Mesomorphic: Somatotype described as being muscular, strong, and possessing weight relatively proportional to height.

Endomorphic: Somatotype described as being rounder and relatively heavy for height.

Waist-to-hip ratio: Ratio of waist circumference to hip circumference often associated with disease risk.

Crural index: Ratio of the length of the tibia to the length of the femur.

Anatomical position: Reference position defined by standing erect with all joints extended, feet parallel, palms facing forward, and fingers together.

Cardinal plane: Plane that passes directly through the midline of the body.

Sagittal plane: Vertical plane dividing the body into right and left halves.

Frontal plane: Vertical plane dividing the body into anterior and posterior halves.

Transverse plane: Horizontal plane dividing the body into superior and inferior halves.

Mediolateral axis: Axis that passes horizontally side to side and is perpendicular to the sagittal plane.

Anteroposterior axis: Axis that runs horizontally from front to back and is perpendicular to the frontal plane of motion.

Superoinferior axis: Axis that passes up and down and is perpendicular to the transverse plane.

Center of mass: The point that represents the average location of a system’s mass.

Center of gravity: The point at which the force of gravity seems to be concentrated.

Line of gravity: A vertical line representing gravity that passes though a system’s center of mass.

Cartesian or rectangular coordinate system: A frame of reference defined by an origin and two or three orthogonal axes, each passing through the origin and defining one spatial dimension.

Origin (O): A stationary point in the environment, from which all measurements are made.

Global reference frame: A fixed frame of reference that allows the location of any point to be specified with respect to a defined origin.

Local reference frame: A frame of reference attached to and moving with the system of interest.

Roll Rotation of a system around the x-axis.

Yaw Rotation of a system around the y-axis.

Pitch Rotation of a system around the z-axis.

Degrees of freedom (DOF): The number of independent ways in which a system can move.

Free-body diagram: A simplified representation of a system free of the movement environment.

Flexion: Segmental motion in a sagittal plane, around a mediolateral axis, and away from the anatomical position.

Extension: Returns a segment to the anatomical position in a sagittal plane around a mediolateral axis and is described as increasing the angle at the joint.

Abduction: Motion in a frontal plane and around an anteroposterior axis that moves the segment away from the anatomical position.

Adduction: Frontal plane motion that returns the segment to the anatomical position.

Eversion: Frontal plane motion around an anteroposterior axis such that the sole of the foot rotates outward or laterally.

Inversion: Frontal plane motion around an anteroposterior axis such that the sole of the foot rotates inward or medially.

Deviation: Frontal plane motion around an anteroposterior axis at the wrist.

Pronation: Rotation at the radioulnar joint around a superoinferior axis that causes the palm to turn toward the body (medially and posteriorly).

Supination: Transverse plane motion that returns the radioulnar joint toward the anatomical position (palm moves anteriorly).

Closed skill: Skill performed under standardized or predictable environmental conditions.

Open skill: Skill performed in a changing or unpredictable environment.

Motion: A change in position with respect to both spatial and temporal frames of reference.

Force: Something that possesses the capability to cause a change in motion or shape of the system.

Relative motion: The motion of one object with respect to a reference object.

Translation: Motion along one of the x-, y-, or z-axes; linear motion.

Rotation: Motion around a fixed axis and therefore in a circular path; angular motion.

Spin: Occurs if all points on one articulating surface come in contact with one point on another articulating surface.

Glide: Sliding or pure translation in which a point on one surface glides or skids over many points of an opposing surface.

Roll: A combination of rotation and translation in which each point on a surface contacts a unique location on the other surface.

Discrete skill: Motion that has a definite beginning and end-point.

Continuous skill: Cycles of motion performed repeatedly with no well-defined beginning or end points.

Repeated discrete: Cycles of motion that are seemingly continuous but require a recovery phase between propulsive actions.

Serial skill: Movement that comprises a series of discrete motions.

Gross movement: Motion that is the result of large muscle group activity and requires little precision.

Fine movement: Motion that is precise and generally controlled by small muscle groups.

Kinetic chain: System of linked rigid bodies subject to force application.

Serial or simple kinetic chain: Kinetic chain in which each segment participates in no more than two linkages.

Complex kinetic chain: Kinetic chain in which a segment is linked to more than two other segments.

Mobility: The total degrees of freedom of a kinetic chain.

Open kinetic chain: Kinetic chain in which motion can occur at one link in the chain without cooperative motion at other links.

Closed kinetic chain: Kinetic chain in which motion at one link is only possible with cooperative movement at other links.

Functional kinetic chain: A complex kinetic chain in which some links are involved in open chain motion and others are engaged in closed chain motion.

Compensatory movements: Adaptations at normal kinetic chain links as a result of abnormal motion at another link.