Moving Objects: Pushing and Pulling Flashcards
In pushing and pulling, the basic joint actions are ________ and _______ in one or more extremities.
flexion; extension
In pushing/pulling, the joint actions of the elbow and shoulder are opposite/simultaneous.
opposite
In pushing/pulling, the joint actions of the hip, knee, and ankle are opposite/simultaneous.
Simultaneous
What are the three natures of force application?
Momentary contact, projection, and continuous application
Examples of momentary contact.
Striking, hitting.
Examples of projection.
shot put, free throw, chest pass
Examples of continuous application
weightlifting, archery
Motion always involves imparting a _____, described in terms of its magnitude, direction, and point of application.
force
Principle of magnitude of force #1: The object will move only if the force is large enough to overcome the object’s ______.
inertia
Principle of magnitude of force #2: Force exerted by the body will transfer to an external object in proportion to ____________________
the counterforce of the feet against the ground
Principle of magnitude of force #3: Optimum summation of internal force is needed if maximum force is to be applied to move an object. In other words, the largest/smallest number of body segments moved through the largest/smallest range of motion.
largest; largest
Principle of magnitude of force #4: For maximum accuracy, the smallest/largest possible number of segments should be used through the smallest/largest possible range of motion.
smallest; smallest
Principle of magnitude of force #5: For a change in momentum to occur, force must be applied over ______.
time – this is impulse!
Principle of direction of force #1: The direction in which an object moves is determined by the ______________.
direction of the applied resultant force.
Principle of direction of force #2: If an object is forced to move along a predetermined pathway, any component of force not in the pathway direction is _______ and may serve to ____________ _______
WASTED; increase friction
Principle of direction of force #3: When optimum force production is the purpose, segments involved should be aligned with the _____________________.
direction of force production
Principle of point of application of force #1: Force applied in line with the object’s center of gravity will result in _______ motion.
linear
Principle of point of application of force #2: Force NOT applied in line with the object’s center of gravity will result in _______ motion.
rotary
Principle of point of application of force #3: If the free motion of an object is interfered with by friction or by the presence of an obstacle, _______ motion may result.
rotary
The magnitude of force may be increased by using the ________________ or __________ to supplement the upper extremities.
lower extremities; body weight
True or False: economy of effort is ensured when the force is applied in line with the object’s center of gravity and in the desired direction.
True; the direction and point of application are interrelated.
A horizontal push should be applied close to the object’s __________.
center of gravity
True or false: It may be advantageous to pull in a slightly downward direction to increase friction.
FALSE: would be better to pull slightly upward to reduce friction. Duh.
Lifting is a form of pushing/pulling upward/downward.
pulling upward
The more ______ the pull and in line with the object’s center of gravity, the more efficient the lift because minimizing the RA reduces the amount of effort needed.
vertical
7 tips for safe and efficient lifting:
1.) Reduce load mass
2.) Avoid floor-level loads
3.) Keep loads close to body for a smaller RA
4.) Maintain neutral spine position
5.) Avoid trunk rotation and lateral flexion while lifting
6.) Maintain a solid base
7.) Lift velocity should be held constant
When holding an object, effort can be minimized by ________________.
supporting the object from underneath with only enough force applied to counteract gravity
When carrying an object, effort can be minimized by ___________________.
lessening the accommodation of the body’s center of gravity (which can be achieved through the mass and distance from the body of the object).
When weightlifting, effort can be minimized by ___________________.
arranging the various levers to minimize torque produced by external resistance while maximizing the available muscle torques.
Punches involve pushing/pulling.
pushing
Whereas karate punches are shorter with no follow-through, boxing punches are __________.
long with a follow-through
When working with long-handled implements, although the implement is light, the forward position means a _____ ____________ ___ and added load on back muscles.
long resistance arm
