Chapter 2- BIOMECHANICS OF RESISTANCE EXERCISE Flashcards
Which of the following is the definition of power? A. Mass x accerleration B. Force x distance C. Force x velocity D. Torque x time
C. FOrce x velocity
To compare performances of OLY weight lifters of different body weights, the classic formula divides the load lifted by the athletes? A. Body weight B. Body weight squared C. Lean body weight D. Body weight to the two-thirds power
D. Body weight to the two-thirds power
During a free weight exercise, muscle force varies with which of the following?
Perpendicular distance from the weight to the body joint
Movement acceleration
A vertical jump involves knee, hip, and shoulder movement primarily in which of the following anatomical plane? A. Sagittal B. Perpendicular C. Frontal D. Transverse
A.Sagittal
An athlete is performing a concentric isokinetic elbow flex ion and extension exercise. Which of the following types of levers occur at the elbow during this exercise? I.first class II. Second class III. Third class
First and third class
____ focuses on the mechanisms through which the musculoskeletal components interact to create movement.
Biomechanics
The muscle most directly involved in bringing about a movement is called the prime mover or _____
A. Antagonist
B. Agonist
B.Agonist
The muscle that can slow down or stop the movement is called the___
A. Agonist
B. Antagonist
B.Antagonist
During throwing, the triceps act as an ____, extending the elbow to accelerate the ball. As the elbow reaches full extension, the biceps acts as an ____ to slow down elbow extension and bring it to a stop.
A. Antagonist, agonist
B. Agonist, antagonist
B. Agonist, antagonist
A muscle called a ____ when it assist indirectly in a movement
Synergistic
A lever for which the muscle force and resistive force act on opposite sides of the fulcrum
FIrst class lever
The pivot point of a lever
Fulcrum
A rigid or semirigid body that, when subjected to a force whose line of action does not pass through its pivot point
Lever
The ratio of the moment arm through which an applied force acts to that through which a resistive force acts
Mechanical advantage
The perpendicular distance from the line of action of the force to the fulcrum.
Moment arm
Force generated by biochemical activity, or Te stretching of no contractile tissue, that tends to draw the opposite ends of a muscle towards each other
Muscle force
Force generated by a source external to the body that acts contrary to muscle force
Resistive force
A lever for which the muscle force and resistive force act on the same side of the fulcrum, with the muscle force acting through a moment arm longer than that through which the resistive force acts
Second class lever
A lever for which the muscle force and resistive force act on the same side of the fulcrum
Third class lever
The degree to which a force tends to rotate an object about a specific fulcrum
Torque
Most of the skeletal muscles operate at a considerable mechanical ______ due to the lever arrangement within the body and relative to the external forces the body resist.
Disadvantage
When the body is erect, the arms are down at the sides, and the palms face forward?
Anatomical position
Plane of the Bicep curl?
Sagittal
Plane of the standing lateral dumbbell raise?
Frontal plane
Plane of the dumbbell fly
Transverse plane
____ is the ability to exert force.
Strength
The change is velocity per unit time
Acceleration
Acceleration is associated with resistive force according to Isaac Newton’s second law:
Force= Mass x Acceleration
Time rate of doing work
Power
The product of the force exerted on an object and the distance the object moves in the direction the force is exerted
Work
Force x Displacement
Work
Work/time
Power
The angle through which an object rotates is called..
Angular displacement
The objects rotational speed measured in radians per second
Angular velocity
Work= Torque x angular displacement
Rotational Work
The capacity to exert force at any given velocity, and power is the mathematical product of force and velocity at whatever speed?
Strength
Neural control affects the maximal force output of a muscle by determining which and how many motor units are involved in muscle contraction
Recruitment
The rate at which the motor units are fired?
Rate coding
___ muscle has fibers that align obliquely with the tendon, creating a featherlike arrangement.
Pennate
The angle between the muscle fibers and an imaginary line between the muscle’s origin and insertion.
Angle of pennation
When a muscle is at its resting length, the ____ and ____ filaments lie next to each other, so that maximal number of potential cross ridge sites are available. The muscle can generate the greatest force at its resting length.
Actin and myosin
When the muscle shortens because the contractile force is greater than the resistive force
Concentric muscle action
When the muscle lengthens because the contractile force is less than the resistive force.
Eccentric muscle action
WHen the muscle length does not change because the contractile force is equal to the resistive force.
Isometric muscle action
Advantages of the stack machines
- safety
- Design flexibility
- Ease of use
Advantages of free weights
- Whole body training
2. simmulation of real-life activities
_____ force can act in any direction.
Inertial
The resistive force encountered when one attempts to move an object while it is pressed against another object.
Friction
The resistive force encountered by an object by moving through a fluid, or by a fluid moving past or around and object or through and opening
Fluid resistance
Two sources of fluid resistance are?
Surface drag
Toward the anterior
Ventral
Toward the posterior
Dorsal
The glottis is closed, thus keeping air form escaping the lungs, and the muscles of the abdomen and rib cage contract, creating rigid compartments of liquid in the lower torso.
Valsalva maneuver
