Fundamentals of Biomechanics

284 FUNDAMENTALS OF BIOMECHANICS
Archimedes' principle: the magnitude of
the buoyant force is equal to the weight
of the fluid displaced
arthrokinematics: the major, freely moveable
rotations allowed at joints
balance: a person's ability to control their
body position relative to some base of
support
balance principle: a biomechanical application
principle which states that the
stability and mobility of a body position
are inversely related
ballistic: explosive, momentum-assisted
movement
bandpass filter: a filter designed to pass a
range (bandpass) of frequencies, removing
frequencies above or below
this desirable range
bending: a combination of forces on a
long body that tends to bend or curve
the body creating tensile loads on
one side and compression loads on the
other side
Bernoulli's principle: the pressure a fluid
can exert decreases as the velocity of
the fluid increases
Bernstein's problem: a theory of motor
control in which skill learning involves
the reduction of redundant degrees of
freedombilateral deficit: simultaneous
activation of two limbs that causes less
force generation than the sum of the
two individually activated limbs
biomechanics: study of the motion and
causes of motion of living things
boundary layer: the layers of a fluid in
close proximity to an object suspended
in the fluid
buoyancy: the supporting or floating force
of a fluid
center of buoyancy: the point at which the
buoyant force acts
center of mass/gravity: the point that represents
the total weight/mass distribution
of a body; the mass centroid is the
point where the mass of an object is balanced
in all directions
center of percussion: a point on a striking
object where impact with another object
results in no reaction force at an
associated point on the grip (see
“sweet spot”)
center of pressure: the location of the vertical
ground reaction force vector; the
center of pressure measured by a force
platform represents the net forces in
support and the COP may reside in regions
of low local pressure
coactivation: simultaneous activation of agonist
and antagonist muscles (co-contraction)
coefficient of drag: a measure of the relative
fluid resistance between an object
and a fluid
coefficient of friction: a measure of the
resistance to sliding between the surfaces
of two materials
coefficient of lift: a measure of the lift force
that can be created between an object
and a fluid
coefficient of restitution: a measure of the
relative elasticity of the collision between
two objects
common mode rejection: a measure of the
quality of a differential amplifier in rejecting
common signals (noise)
compression: a squeezing mechanical loading
created by forces in opposite directions
acting along a longitudinal axis