| A | B |
|---|
| biomechanics | applying mechanical physics principles to the movement of the body |
| static | nonmoving system |
| dynamic | moving system |
| force | push or pull that acts on an object |
| torque | a force that cause rotation around an axis |
| law of inertia | an object at rest or an object in motion will remain that way unless acted on by another force |
| law of acceleration | the amount of acceleration is related to the amount of force applied. i.e. a force twice as strong will make the object move twice as far |
| newtons second law | acceleration is inversely proportional to the mass of the object i.e. an object twice as heavy will travel half as far with the same amount of force applied |
| law of action-reaction | every action has an equal and opposite reaction |
| linear force | 2 or more forces acting along the same line |
| parallel force | forces acting in the same plane, in the same or opposite directions |
| concurrent forces | 2 or more forces acting at the same point but in different directions |
| force couple | when 2 or more forces act in different directions and cause a rotating movement |
| stabilizing force | the force is directed toward the joint, pulling the two bones together |
| dislocating force | the force causes a distraction of the joint |
| center of gravity | the balance point of the object in which torque is equal on all sides |
| base of support | the part of the body that is in contact with the supporting surface |
| line of gravity | imaginary vertical line passing through the center of gravity toward the earth |
| stable equilibrium | a change in the center of gravity will need to occur in order to unbalance the object |
| unstable equilibrium | only a slight force will disturb the balance of the object |
| first class lever | axis is in the middle with force and resistance on either side |
| second class lever | resistance is in the middle with the axis and force on either side |
| third class lever | force is in the middle with the axis and resistance on either side |
| lever for power | second class |
| lever for range of motion | third class |
| lever for balance | first class |
| fixed pulley | acts as a first class lever to move an object by changing the direction of the force |
| movable pulley | acts to increase the mechanical advantage by decreasing the amount of force necessary to move the object by increasing the distance which it must be lifted |
| wheel and axle | less force is required to turn by using a longer lever |
| inclined plane | less force is required when a longer ramp with less incline is used |
