Levers

give the location in the body of each component of a lever system

lever - bone

fulcrum - joint

effort - muscular force

load - weight/resistance

describe each class of lever

1st class - fulcrum is in the middle of the load + effort

2nd class - load is in the middle of fulcrum + effort

3rd class - effort is in the middle of fulcrum + load

give two examples of each class of lever

1st class - downward phase of bicep curl, extension of neck (header in football)

2nd class - standing on tip-toes on edge of diving board, using fingers to push off in swimming

3rd class - upward phase of bicep curl, flexion of knee

describe effort + load arm

effort arm - distance between fulcrum + effort

load arm - distance between fulcrum + load

benefit + drawback of efficiency of 2nd class lever system

benefit - less effort to lift heavy load (mechanical advantage)

drawback - smaller RoM so difficult to put speed/acceleration on body

benefit + drawback of efficiency of 3rd class lever system

benefit - bigger RoM to generate momentum + accelerate a body

drawback - more effort to lift heavy load (mechanical disadvantage)

define mechanical advantage + disadvantage

mechanical advantage - effort arm is greater than load arm so large load can be moved with relatively small effort

mechanical disadvantage - load arm is greater than effort arm so large effort required to move relatively small load