Biomechanics
5/6/1999

Levers
•	Fulcrum—what the lever is anchored to
•	Allows the lever to do something for us
•	Examples
•	Occiput and C1—center is a little posterior
•	Vertebrae—center of rotation is in the center
•	Type 1
•	Fulcrum is in the middle
•	F1 * d1 = F2 * d2
•	Have a set distance of the muscle to the joint 
•	The other distance is how far the center moves
•	The force applied to this distance is the weight going through the center
•	Then determine the amount of force needed to counterbalance
•	Gastroc and soleus are the only two muscles that fire during perfect upright posture
•	Counter force in the disk is equal to the amount of force down and the calculated force
•	Type 2 or 3
•	Fulcrum is at the end 
•	Center of gravity is off centered do to the difference thickness of the muscles
•	Muscle A requires 3 1/3 Forces –efficient for work
•	Muscle B requires 25 Forces—not efficient for work
•	We do not have any muscles like A
•	Advantages to muscles like B 
•	Mobility
•	Greater ROM
•	Faster movement (velocity)
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