Chapter 1 Flashcards
Slight, passive, convolutional movements allowed in most joints (also called joint play)
Accessory Movements
Push or pull generated by stimulated muscle
Active Force
Motion caused by stimulated muscle
Active Movement
Muscle or muscle group that is most directly related to the initiation and execution of a particular movement
Agonist Muscle
The generally agreed on reference position of the body used to describe the location and movement of its parts. In this position, a person is standing fully upright and looking forward, with arms resting by the side, forearms fully supinated, and fingers extended
Anatomical Position
Angle formed between a tendon of a muscle and the long axis of the bone into which it inserts
Angle-of-Insertion
Muscle or muscle group that has action opposite to a particular agonist muscle
Antagonist Muscle
Motion of roll, slide, and spin that occur between curved articular surfaces of joints
Arthrokinematics
Angular motion of an object in a direction perpendicular to its longitudinal axis; often used to describe a motion in the horizontal plane
Axial Rotation
An imaginary line extending through a joint around which rotation occurs (also called the pivot point or the center of rotation)
Axis of Rotation
Effect of a force that deforms a material at right angles to its long axis
Bending
Point at the exact center of an object’s mass
Center of Mass
Unique position of most joints of the body where the articular surfaces are most congruent and the ligaments are maximally taut
Close-Packed Position
The inverse of stiffness
Compliance
A force, applied perpendicularly to the contact surface, that pushes or pulls on one object directly against another
Compression
Activated muscle that shortens as it produces a pulling force
Concentric Activation
A progressive strain of a material when exposed to a constant load over time
Creep
Number of independent directions of movements allowed at a joint
Degrees of Freedom
change in the linear or angular position of an object
Displacement
Type of movement in which the distal segment of a joint rotates relative to a fixed proximal segment (also called an open kinematic chain)
Distal-on-Proximal Segment Kinematics
A force, applied perpendicularly to the contact surface, that pushes or pulls one object directly away from another
Distraction
Activated muscle that is producing a pulling force while being elongated by another more dominant force
Eccentric Activation
Property of a material demonstrated by its ability to return to its original length after the removal of a deforming force
Elasticity
Push or pull produced by sources located outside the body
External Force
Perpendicular distance between an axis of rotation and the external force
External Moment Arm
Product of an external force and its external moment arm
External Torque
A push or a pull that produces, arrests, or modifies a motion
Force
Two or more muscles acting in different linear directions, but producing a torque in the same rotary direction
Force-Couple
Potential acceleration of a body toward the center of the earth as a result of gravity
Force of Gravity
Push or pull produced by a structure located within the body
Internal Force
Perpendicular distance between the axis of rotation and the internal (muscle) force
Internal Moment Arm
Product of an internal force and its internal moment arm
Internal Torque
Activated muscle that maintains a constant length as it produces a pulling force
Isometric Activation
Force that exists at a joint, developed in reaction to the net effect of internal and external forces
Joint Reaction Force
Branch of mechanics that deceives the motion of a body, without regard to the forces or torques that may produce the motion
Kinematics
Series of articulated segmented links, such as the connected pelvis, thigh, leg, and foot of the lower extremity
Kinematic Chain
Branch of mechanics that describes the effort of forces and torques on the body
Kinetics
Relative moment arm length possessed by a particular force
Leverage
Direction and orientation of a muscle’s force
Line of Force
Direction and orientation of the gravitational pull on a body
Line of Gravity
General term that describes the application of a force to a body
Load
Axis that extends within and parallel to a long bone or body segment
Longitudinal Axis
Positions of most synovial joints of the body in which the articular surfaces are least congruent and the ligaments are slackened
Loose-Packed Positions
Ratio of the IMA to the EMA
Mechanical Advantage
Perpendicular distance between an axis of rotation and the line of force
Moment Arm
Potential of a muscle to produce a torque within a particular plane of motion and rotation direction
Muscle Action
Push or pull generated by sources other than stimulated muscle, such as tension in stretch periarticular connective tissues, physical contact, and so forth
Passive Force
Motion produced by a source other than an activated muscle
Passive Movement
Property of a material demonstrated by remaining permanently deform after removal of force
Plasticity
Force divided by a surface area
Pressure
Phenomenon in which relatively low-level tension within stretched connective tissues performs a useful function
Productive Antagonism
Type of movement in which the proximal segment of a joint rotates relative to a fixed distal segment
Proximal-on-Distal Segment Kinematics
Arthrokinematic term that describes when multiple points on one rotating articular surface contact multiple points on another articular surface
Roll
Angular motion in which a rigid body moves in a circular path around a pivot point or an axis of rotation
Rotation
A force produced as two compressed objects slide past each other in opposite directions
Shear
Arthrokinematic term describing when a single point on one articular surfaces contacts multiple points on another articular surface
Slide
Arthrokinematic term describing when a single point on one articular surface rotates on a single point on another articular surface
Spin
Ratio of stress to strain within an elastic material
Stiffness
Ratio of a tissue’s deformed length to its original length
Strain
Force generated on a tissue resists deformation, divided by its cross-sectional area
Stress
Two or more muscles that cooperate to execute a particular movement
Synergists
