1. Levers and systems

2. Learning goals I will be able to identify the three classes of levers.
I will be able to distinguish between static and dynamic systems.
I will be able to list the 7 biomechanical principles.

3. Levers!

4. Parts of a lever Load Effort Arm Load Arm Effort
the movement of force is the single most important concept in understanding human movement.
Effort Arm
Load Arm
Fulcrum
(axis)
Effort
(force)
Load
(resistance)
The purpose of a lever is to
gain a mechanical advantage.

5. Anatomical levers
the force applied through muscle contraction (the pull on the movable bone at the attachment site) is the “effort.”
the joint where the bones come together is the axis or “fulcrum.”
the mass to be moved by the muscle is the “load.”

6. 3 Types of levers
classification of lever based on way load, effort, and fulcrum are positioned in relation to each other.
result is a mechanical advantage of either increased speed and range of motion or increased force.

7. 1st class fulcrum always positioned between load and effort.
when fulcrum is midway between effort and load no mechanical advantage is gained.

8. 1st class when fulcrum is closer to effort… Mechanical Advantage:
effort must be greater than resistance of load.
distance the effort moves is less than distance the load moves.
Increased Speed and Range of Motion
Mechanical Advantage:

9. 1st class when fulcrum is nearer to load… E L Mechanical Advantage
effort is less than resistance
effort moves farther than load moves
lever favours force which means athlete can get more force out than they put in
Mechanical Advantage
Increased Force

10. 2nd class E L
load always between fulcrum and effort.

11. 2nd class Mechanical Advantage Increased Force
always favor force at expense of speed or range of motion.
effort will always increase the force applied.
Mechanical Advantage
Increased Force

12. 3rd class effort acts between fulcrum and load.
most common type of lever found within human body.
effort acts between fulcrum and load.
movement effort results in movement load in same direction.

13. Increased Speed and Range of Motion
3rd class
always move load through a larger range of motion than effort
effort will always increase speed at which the load moves.
effort is always greater than load resulting in increase in speed.
Mechanical Advantage
Increased Speed and Range of Motion

14. What type of lever? Device Lever Type Hammer Spoon Nutcracker Oars
Hockey Stick
Wrench

15. Complete the chart Movement Lever Class Effort Force Fulcrum/Axis
Resistance
Knee Extension
Shoulder Adduction
Elbow Extension
Hip Extension

16. Static and dynamic systems

17. 7 biomechanical principles
Biomechanical Concept
Principles
Stability
1. Stability
Maximum Effort
2. Production of Maximum Force
3. Production of Maximum Velocity
Linear Motion
4. Impulse
5. Direction of Application of the Applied Force
Angular Motion
6. Production of Angular Motion (Torque)
7. Conservation of Angular Momentum

18. Statics
branch of mechanics that deals with objects or bodies in a state of constant, unchanging motion.
the rate of change of motion of an object or body is unchanging over time
a gymnast holding a stationary pose on a balance beam
a high diver in free fall
Pilates or Yoga instructor

19. Dynamics
branch of mechanics studying changes in the motion of objects or bodies as a result of the actions of forces
a dynamic system is one that experiences a change in the rate at which it is moving as a result of forces applied to it
a rugby player weaving his or her way down the field
show jumping equestrian horse
changes in our movement patterns are the product of multiple internal as well as external forces.

20. Learning goals I will be able to identify the three classes of levers.
I will be able to distinguish between static and dynamic systems.
I will be able to list the 7 biomechanical principles.