Unit 5 Biomechanics of Exercise (Week 3) Flashcards
Understand what occurs during execution of strength and other exercises. Define the mechanical and physical factors involved in exercise and movement.
biomechanics
the study of movement.
mainly with physical factors such as speed, mass, acceleration, levers, and force along with the physical functions of the movement
Stability is
the ability to maintain a balanced state
Stability principle: the larger the base of support,
the greater the body’s stability
Stability principle: the lower the body is,
the more stable it becomes.
Bent knee position prevents (2)
knee injuries and lower-body movement and keeps the spine vertical when performing upper body twisting
If the feet are parallel and shoulder-width apart (A), the weight should be
close to you or overhead.
ex: back squat
In a stride position (B), you can better balance the weight in a
forward–backward direction.
ex: standing chest press
Force is
the interaction that creates work, action, or physical change.
Muscular force is exhibited in
a push or pull type motion.
four components of force:
magnitude, direction, point of application, and line of action.
Magnitude refers to
how much force is applied to the dumbbells, barbells, or machine handles.
direction:
The way in which the force is applied
Point of application refers to
where the force is applied on the body or implement being used
Line of action (also line of force) refers to
an imaginary straight line drawn from the point of application of force through the direction of force
The angle at which a muscle pulls relative to the long axis of the bone on which it pulls.
angle of pull
mechanical advantage,
ability to do more work at a specific angle
work
F x D. Measured in foot-pounds and similar units. Example: Lifting a 200-pound barbell 8 feet and lifting a 400-pound barbell 4 feet each require 1,600 foot-pounds of work.
power:
The work done in a unit of time.
The faster the work is done, t
he greater the amount of power;
Newton’s first law states
an object at rest tends to stay at rest, and an object in motion tends to stay in motion; this is the essence of inertia.
Resting inertia
when an object is at rest, it will stay at rest unless acted upon by some outside force
Moving inertia
when an object is in motion, it will remain in motion unless acted upon by some outside force
range of motion (ROM):
the movement of a joint from full flexion to full extension.
in order to create a force, you must place
a mass into motion with acceleration and a change in velocity.
mass multiplied by velocity is known as
momentum
mass
A body of coherent matter.
acceleration
The rate of change of velocity per unit of time.
velocity
The speed of something in a given direction.
Newton’s third law of motion
objects in contact exert equal and opposite forces on each other.
lever:
Rigid bar that turns about an axis of rotation or a fulcrum.
fulcrum:
The point on which a lever rests or is supported and on which it pivots.
first-class lever:
Fulcrum in the middle, the effort is applied on one side of the fulcrum and the resistance on the other.
ex: nodding your head
second-class lever:
A lever in which the load lies between the fulcrum and the effort.
ex: push-up
third-class lever:
A lever in which the effort is placed between the fulcrum and the load.
ex: bicep attaching to elbow
torque:
the magnitude of twist around an axis of rotation (fulcrum).
gravity:
The downward pulling force that creates resistance.
center of gravity:
The point in the body around which your weight is equally distributed.
line of gravity:
A vertical line straight down from the center of gravity.
kinesthesis:
The ability to perceive your position and movement of the body or body limbs in space.
visual reference point:
A chosen point of focus to aid in stability and balance.
Force transmission arrangements in the body include
wheel and axle, pulley, pushing, and pulling.
