1. Biomechanical theory and concepts

2. Learning goals We are learning the basics of biomechanics.
We are learning the types of rotation.
We are learning to apply Newtonian physics to the body.

3. Compare the numbers

4. biomechanics
the science examining the internal and external forces acting on a human body and the effects produced by these forces
internal forces produced by muscles and tendons working against external forces of gravity, air resistance, water resistance and friction

5. aim Medicine Biomedical Engineering Sport Equipment Design
Rehabilitation
Ergonomics

6. background
movement of the body is produced by the rotation of body segments around joints
movement of joints occur when muscles contract (ex . biceps)
the skeleton is the structural framework; muscles move body segments
movement is caused by forces

7. background force is a push or pull
causes movement or a change in movement or direction
vector quantities because have both a size and direction
standard unit of force is the Newton - N
the amount of force and speed muscles can produce depends on
size of the muscles
angle of pull
type of resistance training

8. Types of motion Linear or Translation
movement in a particular direction; linear force acting on an object, resulting in a straight line
Angular or Rotary
movement around an axis; force acts “off-centre” causing spin
General
combination of linear and angular (most motion)

9. Determining motion
centric force: force applied directly through the centre of an object or body and it results in linear motion only
the object or body will move linearly in the direction of the applied force.
eccentric (off-centre) force: force directed through a point other than the centre of the object or body
always results in rotational motion (and sometimes linear motion, too).

10. Humans and rotational motion
rotations of projectiles or other objects (e.g., the swing of a hockey stick)
rotations of the entire human body about one of three axes (e.g., the tumble of a gymnast)
rotations of individual body segments (e.g, the throwing motion of a softball pitcher’s arm)

11. Newton’s laws

12. newton 3 laws established foundations of classical mechanics
see Costella for a brief and likely interesting history!

13. 1st Law of inertia
“An object remains at rest or in a state of constant motion unless acted upon by an unbalanced external force.”
the heavier an object is, the harder it is to change it’s motion.
this resistance to a change in motion is called inertia.

14. examples car skidding off icy road on a curve
gymnast maintaining a stationary pose on balance beam
curling rock if on a frictionless surface

15. 2nd law of acceleration
“In the presence of an unbalanced external force, an object will accelerate in the direction of that force”.
the heavier the body, the smaller the acceleration.

16. examples
F = ma
as more mass is added to a blocking sled, a football lineman must generate more force for the sled to accelerate at the same rate.
proper technique and strength allow professional tennis players to apply more force when they hit the ball, causing the ball to accelerate faster.

17. 3rd law “Every action has an opposite and equal reaction”.
if one object exerts a force on a second object, the second object exerts the exact same force on the first but in the opposite direction.

18. examples
punch a wall, it punches back with the same force… you break your hand.
kick a table, it kicks you back with the same force… you stub your toe.
basketball or volleyball player jumping
sprinter in starting blocks

19. Learning goals We are learning basics of biomechanics.
We are learning the types of rotation.
We are learning to apply Newtonian physics to the body.

20. Please complete
Newton Law HO