1. Musculoskeletal “Levers”
The Relationship between the Muscular and Skeletal System

2. Move It Move It
Your muscles pulling on bone often works like a SIMPLE MACHINE called a LEVER.

3. LEVER LIMB LIMBO
Most of the bones of the limbs (ARMS and LEGS) act as Levers.
LEVERS: simple machines made up of a BAR that moves around a FIXED POINT.

4. Parts of the MACHINE Lever: rigid bar that moves on a fixed point
Fulcrum: a fixed point
Effort: the applied force on the lever
Load: what is being moved (the Resistance)

5. =Bone is equal to the Lever =Joint is equal to the Fulcrum
PARTS of the Body
=Bone is equal to the Lever
=Joint is equal to the Fulcrum
=Muscle (Contraction) equals the Effort (Force)
=Thing being lifted equals the Load (Resistance)

6. Mechanical Advantages/Disadvantage
IF the Load is Close and the Effort applied far from the fulcrum
Disadvantage
IF the Load is Far from the Fulcrum and the Effort is applied near the fulcrum.

7. Classes of Levers
First Class: The FULCRUM is in the MIDDLE of the LOAD and the EFFORT
Ex. Seesaw, scissors, nodding your head.

9. Second Class Lever
The LOAD is in the MIDDLE of the EFFORT and the FULCRUM.
Ex. Wheelbarrow, Standing on your toes.

11. Third Class Lever
The EFFORT is in the MIDDLE of the LOAD and the FULCRUM.
Ex. Tweezers, or Lifting weights (arm curl)

13. Question Section
Why are Levers Useful?