1. LEVERS

2. A lever is basically a rigid structure, rotating around a fixed point.
A lever consists of three parts :
1. Load (resistance)
2. Effort (force)
3. Pivot (fulcrum)
List the two main functions of a lever :
To move greater loads with a set amount of force e.g levering a heavy box with a crowbar
To help move loads at greater speed eg golf club or a badminton racquet.
Levers

3. Internal and External Levers
External levers allow force and speed to be applied from outside the body
the oars of a boat
the pole used in pole vaulting
Internal levers are inside the body and are the most important levers for human movement
Joint = fulcrum
Bones = lever arms
Muscles = effort
Internal and External Levers

4. There are 3 types of levers, fill in the grid below
Class
Illustration
Definition
Examples
First
The pivot lies between the effort and the load
See saw, crowbar
Oar in a boat
Second
The load lies between the pivot and the point of effort
Wheel barrow,
Opening a door by the handle, diving board, press ups
Third
The effort lies between the load and the pivot
Biceps curl, softball bat, badminton racket

5. THIRD CLASS LEVERS Are the most common lever type in the human body
They allow for more speed to be produced
Shorter lever for strength e.g. gymnastics rings
Longer lever for speed e.g. straight leg when kicking ball
THIRD CLASS LEVERS

6. LEVER ARMS (bones) A force arm (FA) is defined as
The distance from where effort is applied to the pivot (e.g. muscle attachment to the joint)
A resistance arm (RA) is defined as
The distance from the load to the pivot
LEVER ARMS (bones)

7. What is the advantage of using a racket in badminton?
Lengthens the lever therefore longer RA
Longer RA = higher velocity or speed can be attained when hitting the shuttle
Speed is transferred into the shuttle!
THIRD CLASS LEVERS

8. THIRD CLASS LEVERS Same for both. 3rd Class lever
Pivot = shoulder joint
Effort = deltoids
Load = racket head
THIRD CLASS LEVERS

9. How does altering the RA (bending and then straightening joints) make badminton shots more effective?
Bending arm reduces lever length allowing lever to generate more force and to be rotated with more speed
When straightened, speed at end of lever is maximised allowing racket head to travel at full speed.
Used to strike the shuttle faster and propel it forward at high speed!
THIRD CLASS LEVERS