Biomechanics/Applied Kinesiology Flashcards
lever
a rigid bar with a fixed point around which it can rotate when an external force is applied
Linear momentum
the force with which a body moves; equal to its mass times velocity
fulcrum
the fixed point of a lever
axis of rotation
the imaginary line or point about which a lever rotates; the axis of rotation is perpendicular to the plane of movement
lever arm
the perpendicular distance from the axis of rotation to the line of the force
force arm (Fa)
the lever arm length of the motive force
Resistance arm (Ra)
the lever arm length of the resistance
the lever is in balance if:
the force times the force arm is equal to the resistance times the resistance arm
torque
the turning effect of a force operating on a lever at some distance from the axis of rotation
how is the amount of torque found?
by multiplying the amount of force by the length of the lever arm
the body consists of which type of lever?
third class levers
what is a third class lever?
one in which the force (F) acts between the axis (X) and the resistance (R)
are most muscles in the human body longitudinal or penniform?
penniform
what is a penniform muscle?
one in which the muscle fibres lie diagonal to the line of pull.
static (isometric) contraction
when resistance is greater than or equal to the tension in a muscle and no visible movement occurs
concentric (shortening) contraction
when the force generated by a muscle is greater than an applied resistance
eccentric (lengthening) contraction
occurs when an external force exceeds the contractile force generated by a muscle.
sagittal plane
the plane created by bisecting the body along its line of bilateral symmetry
frontal (coronal) plane
A coronal plane (also known as the frontal plane) is any vertical plane that divides the body into ventral and dorsal (belly and back) sections.
transverse plane
The transverse plane (also called the horizontal plane, axial plane, or transaxial plane) is an imaginary plane that divides the body into superior and inferior parts. It is perpendicular to the coronal and sagittal planes
glenohumeral joint
shoulder joint
what kind of joint is the glenohuneral joint?
multiaxial; it comprises the articulation between the glenoid fossa of the scapula and the humerus
