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H.
Basic Movement Actions
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flexion vs extension
(hyperextension)
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movement
which brings the limbs or body into a more bend vs straighten position
(often in sagittal plane)
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abduction
vs adduction, leg or arm
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moving
extremity away from vs toward the body (often in a frontal plane)
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circumduction
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circular
movement combining flextion, abduction, extension, and adduction
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pronation
vs supination, forearm
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axially
turning the forarm so the palm faces backdown/downward vs
forward/upward
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dorsiflexion
vs plantar flextion
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bending
the ankle so the foot points upward vs downward
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eversion
vs inversion, foot
|
to
rotate outward vs inward (e.g., toes), typically a combination of plantar
flextion/supination/adduction vs dorsiflextion/pronation/abduction.
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I.
Biomechanics and Movement Science Terminology
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Active
Range Of Motion
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The
range through which a joint can move (typically angular, in one degree of
freedom), without assistance or resistance.
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Ambulation
|
To
walk.
|
Antagonist
Muscle
|
A
muscle whose action is the opposite to that of another muscle.
|
Concentric
action
|
A
muscle that shortens while activated.
|
Constitutive
relation
|
The
governing equation describing the relation between two variables (e.g.,
force -extension relation for a spring).
|
Dynamics
(Kinetics)
|
The
study of the forces and motion caused by the forces.
Forward dynamics: forces are inputs, motion evolves due to the
dynamical equations of motion. Inverse
dynamics: motions are known, forces are then back-calculated.
|
Eccentric
action (plyometric)
|
A
muscle that lengthens while activated
|
Isokinetic
|
An
activated muscle "contraction" in which its velocity is constant
(specified) and the force can change (e.g., depends on the level of
effort).
|
Isometric
|
An
activated muscle "contraction" in which its length does not
change (special case of isokinetic in which the velocity is zero).
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Isotonic
|
An
activated muscle "contraction" in which the force is constant
and the length can change (e.g., shorten)
|
Line
of action
|
The
conceptual center line of the pulling force of a muscle
|
Motor
unit
|
Motoneuron
and the muscle fibers it innervates
|
Multiarticular
|
A
muscle crossing more than one joint.
|
Muscle
fiber composition
|
The
relative composition of "slow" and "fast" muscle
fibers in a muscle.
|
Range
Of Motion
(Rom)
|
The
normal range of movement of any body joint. Range of motion also refers to
exercises designed to maintain this range and prevent contractures. The
"passive" ROM is the range through which a joint can be moved by
an external force (e.g., applied by a therapist).
|
Redundancy
(actuator, kinematic)
|
Actuator
redundancy refers to the concept of there being more muscle actuators that
necessary to move in the joint degrees of freedom (e.g., more than two
muscles cross the elbow joint). Kinematic redundancy refers to the
there being more joint degrees of freedom that end-point degrees of
freedom (e.g., arm).
|
Rigid
Body
|
A
body segment that is assumed not to deform; commonly used assumption
for movement biomechanics studies (e.g., limb segment).
|
Stiffness
|
The
local stiffness of a tissue (such as muscle, ligament, bone) or endpoint
(such as at hand) is the change in force divided by the change in
length. In reality the "stiffness" can depend on a range
of factors, such as the magnitude of the applied change (if nonlinear) or
whether it is measured immediately or in steady-state (if
history-dependent).
|
Synergist
muscle
|
Muscles
working together to cause similar actions.
|
Yield
point
|
The
point of stress on the load deformation curve that separates the elastic
range from the plastic range, at which point increased load causes
residual deformation after the load is removed.
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