1. LEVERS

2. 4.3.5 Distinguish between first, second and third class levers.

3. LEVERS DEFINED Levers help us lift or carry weight
All levers have a(an)
Axis = Fulcrum = Pivot = Joint
The pivot point
Resistance = Weight = Load
Is what the lever system is trying to move, lift, or break
The weight we would be lifting, pushing, or pulling
Force = Effort = muscle
What makes the lever work
Muscles contracting
Source: IB SEHS textbook and

4. First Class Lever
The fulcrum (axis) lies between the effort (force) and resistance (weight). Opposite sides of the fulcrum.
E.g. See saw, Triceps pushdown
Rare in physical activity
Look on page 96 in your text
Picture source: womenshealthmag.com

5. Second class lever
The resistance (weight/load) lies between the fulcrum and the point of effort (force).
E.g. Wheel barrow, Tennis ball machine, toe/calf raises
Extremely rare in physical activity
Picture source: directlyfitness.com

6. Third class lever
The effort (force) lies between the resistance and the fulcrum
Very common in physical activity, the human body
E.g. Bicep curls
Picture source: quickweightlossprogram.net; constructionknowledge

7. 4.3.6 Label Anatomical representations of levers
Limit to triceps – elbow joint, calf-ankle joint, and biceps-elbow joint. You should be able to indicate effort, load, fulcrum and the muscles and bones involved.
Image source:Avstop