Sources of Resistance to Muscle Contraction Flashcards
What are the most common sources of resistance?
Inertia, gravity, friction, fluid resistance, and elasticity
An objects weight is equal to its _____ times the local _____ due to _____.
mass; acceleration; gravity
The pound is a unit of ____ NOT _____.
force; mass
By definition, the moment arm by which a force produces torque is _____ to the line of action of the force.
perpendicular
The moment arm of a weight is always _____.
horizontal
Torque is a product of…
weight and the horizontal distance from the weight to the pivot point (joint).
Describe the “bracketing technique”.
When a sport movement is performed with less than and more than normal resistance.
What is friction?
Resistive force encountered when one attempts to move an object while it is pressed against another object.
It takes more force to _____ movement than to _____ movement.
initiate; maintain
_____ resistance does not change as speed increases.
Friction
_____ output increases as speed increases.
Power
In the transition from a lower to a higher speed there is added resistance due to _____.
acceleration
Define fluid resistance
The resistive force encountered by an object moving through a fluid, or by a fluid moving past or around an object.
Identify 2 sources of fluid resistance.
Surface drag & Form drag
Define surface drag.
The friction of a fluid passing along the surface of an object.
