EXAM Flashcards
kinesiology
the study of motion; focuses on the anatomical, physiologic and biomechanics interactions within the musculoskeletal system
biomechanics
the study of the mechanics of biologic systems; application of mechanical principles in the study of living organisms
acceleration
change in velocity of a body over time, expressed in linear and angular terms
accessory movements
slight, passive, convolutional movements allowed in most joints
active force
push or pull generated by stimulated muscle
active movement
motion caused by stimulated muscle
agonist muscle
muscle or muscle group that is most directly related to the initiation and execution of a particular movement
anatomic position
the generally agreed upon reference position of the body used to describe the location and movement of its parts
angle of insertion
angle formed between a tendon of a muscle and the long axis of the bone into which it inserts
antagonist muscle
muscle or muscle group that has the action opposite to a particular agonist muscle
arthrokinematics
motions of roll, slide, and spin that occur between curved articular surfaces of joints
axial rotation
angular motion of an object in a direction perpendicular to its longitudinal axis, often used to describe a motion in the horizontal plane
axis of rotation
an imaginary line extending through a joint around which rotation occurs (also called the center of rotation)
center of mass
point at the exact center of an object’s mass (also referred to as center of gravity when considering the weight of the mass)
bending
effect of a force that deforms a material at right angles of its long axis; a bent tissue is compressed on its concave side and placed under tension on its convex side
close-packed position
unique position of most joints of the body where the articular surfaces are most congruent and the ligaments are maximally taut
compliance
the inverse of stiffness
compression
a force applied to the contact surface that pushes or pulls one object directly against another
concentric activation
activated muscle that shortens as it produces a pulling force, internal torque > external torque, rotation in direction of activated muscle
creep
a progressive strain of a material (deformation) when exposed to a constant load over time
degrees of freedom
number of independent directions of movements allowed at a joint, a joint can have up to 3 degrees of translation and 3 degrees of rotation
displacement
change in the linear or angular position of an object
distal on proximal segment kinematics
type of movement in which the distal segment of a joint rotates relative to a fixed proximal segment (also called an open kinematic chain)
distraction
a force applied perpendicularly to the contact surface that pushes or pulls one object directly away from another
eccentric activation
activated muscle that is producing a pulling force while being elongated by another more dominant force, external torque > internal torque (joint rotation is dictated by external torque)
elasticity
property of a material demonstrated by its ability to return to its original length after the removal of a deforming force
external force
push or pull produced by sources located OUTSIDE the body, these typically include gravity and physical contact applied against the body
external moment arm
perpendicular distance between an axis of rotation and the external force
external torque
product of an external force and its external moment arm
force
a push or pull that produces, arrests, or modifies a motion
force couple
two or more muscles acting in different linear directions, but producing a torque in the same rotary direction
force of gravity
potential acceleration of a body toward the center of the earth as a result of gravity
friction
resistance to movement between two contacting surfaces
internal force
push or pull produced by a structure located within the body; refers to the force produced by an active muscle
internal moment arm
perpendicular distance between the axis of rotation and internal (muscle) force
internal torque
product of an internal force and its internal moment arm
isometric activation
activated muscle that maintains a constant length as it produces a pulling force (external torque = internal torque)
joint reaction force (JRF)
force that exists at a joint, developed in reaction to the net effect of internal and external forces; includes forces between joint surfaces and forces from any periarticular structure
kinematics
branch of mechanics that describes the motion of a body, without regard to the forces or torques that may produce motion
kinematic chain
series of articulated segmented links such as the connected pelvis, thigh, leg, and foot of the lower extremity
kinetics
branch of mechanics that describes the effect of forces and torques on the body
leverage
relative moment arm length possessed by a particular force
line of force
direction and orientation of a muscle’s force
line of gravity
direction and orientation of the gravitational pull on a body
load
general term that describes the application of a force to a body
longitudinal axis
axis that extends within and parallel to a long bone or body segment
loose-packed position
position of most synovial joints of the body in which the articular surfaces are least congruent and the ligaments are slackened
mass
quantity of matter in an object
mechanical advantage
ratio of the internal moment arm to the external moment arm
moment arm
perpendicular distance between an axis of rotation and the line of force
muscle action
potential of a muscle to produce a torque within a particular plane of motion and rotation direction (also called joint action when referring to a muscle’s potential to rotate a joint)
osteokinematics
motion of bones relative to the three cardinal or principal planes
passive force
push or pull generated by sources other than stimulated muscle, such as tension in stretched periarticular connective tissues, physical contact, and so forth
passive movement
motion produced by a source other than activated muscle
plasticity
property of a material demonstrated by remaining permanently deformed after the removal of a force
pressure
force divided by a surface area (also called stress)
productive antagonism
phenomenon in which relatively low level tension within stretched connective tissues performs a useful function
proximal on distal segment kinematics
type of movement in which the proximal segment of a joint rotates relative to a fixed distal segment (also referred to as a closed kinematic chain)
roll
arthrokinematic term that describes when multiple points on one rotating articular surface contact multiple points on another articular surface
rotation
angular motion in which a rigid body moves in a circular path around a pivot point or an axis of rotation
scalar
quantity, such as speed or temperature that is completely specified by its magnitude and has no direction
segment
any part of a body or limb
shear
a force produced as two compressed objects slide past each other in opposite directions
shock absorption
the act of dissipating a force
slide
arthrokinematic term describing when a single point on one articular surface contacts multiple points on another articular surface (also called glide)
spin
arthokinematic term describing when a single point on one articular surface rotates on a single point on another articular surface
static linear equilibrium
state of a body at rest in which the sum of all forces is equal to zero
static rotary equilibrium
state of a body at rest in which the sum of all torques is equal to zero
stiffness
ratio of stress (force) to strain (elongation) within an elastic material
strain
ratio of a tissue’s deformed length to its original length
stress
force generated as a tissue resists deformation, divided by its cross-sectional area (also called pressure)
synergists
two or more muscles that cooperate to execute a particular movement
tension
application of one or more forces that pulls apart or separates a material (also called a distraction force), used to denote the internal stress within a tissue as it resists being stretched
torque
a force multiplied by its moment arm, tends to rotate a body or segment around an axis of rotation
torsion
application of a force that twists a material around its longitudinal axis
translation
linear motion in which all parts of a rigid body move parallel to and in the same direction as every other point in the body. can occur in a straight line (rectilinear) or in a curved line (curvilinear)
ultimate failure point
length at which a tissue structurally fails and loses its ability to hold a load
vector
quantity, such as velocity or force that is completely specified by its magnitude and direction
velocity
change in position of a body over time, expressed in linear and angular terms
viscoelasticity
property of a material expressed by a changing stress-strain relationship over time
weight
gravitational force acting on a mass
viscosity
a measure of the resistance of a fluid towards being deformed when under shear stress, it is a measure of resistance to flow, heating reduces viscosity
how does the body handle forces?
the ability of the periarticular connective tissues to accept and disperse loads (impacted by aging, trauma, prolonged immobilization, and disease)
cytoplasm
contains many myofibrils that include tiny cylinders consisting of bundles of myofilaments
sarcoplasm
responsible for holding components of the cell, stores molecules required for cellular processes (responsible for giving the cell its shape)
sarcolemma
specialized membrane which surrounds striated muscle fiber cells
T tubules
invaginations of the sarcolemma that form a permeability
calcium
enters and leaves the cell through a distribution of ion channels, transporters, and pumps
inner layer of muscle
endomysium
middle layer of muscle
perimysium
epimysium
outer layer
