BIOMECHANICS DAY 2 Biomechanics basics Newtons Motion Laws

BIOMECHANICS DAY 2

Biomechanics basics Newton’s Motion Laws Classes of levers Work Moment of Force Kinetics Kinematics Mass vs. Weight Center of mass vs. center of gravity Seven Principles of biomechanical analysis Problem solving

Biomechanics Statics: Dynamics: ____________

More closely: Biomechanics: Dynamics Kinetics: __________ Kinematics: _________ Cause and Effect

Kinetics • Forces the ______the movement • Forces tha_______from movement The forces which act on the human body can be INTERNAL: EXTERNAL:

Kinematics The geometry of motion Linear Motion Displacement Velocity Force Mass Rotational Motion

A Closer look at Kinematics • Time: • Displacement: • Velocity: • Acceleration:

Types of Motion Linear (or Translational) Motion: Example: a sprinter accelerating down the track or a hockey player veers to go around another player (resolved in a straight line)

Linear Motion con’t… • Human movements are not always in a straight line- i. e. a wide receiver: • Force as a Vector: force as a push or pull of a certain magnitude in a particular direction. • Using basic trigonometry- a diagonal force vector can be computed for any direction.

Types of Motion • Rotational Motion: Example: ice skater’s spin and a gymnast’s somersault

Rotational motion • Torque (T): • The axis of rotation in the body are joints • Moments/ torques can be positive or negative and therefore we must create a coordinate system to define positive direction

Ice-Skater Spin

• Mass is a Mass Vs Weight • Weight is the • Mass is measured by using a balance comparing a known amount of matter to an unknown amount of matter. • Weight is measured on a scale. • The Mass of an object doesn't change when • Weight does change with location.

Center of Mass vs. Center of Gravity Center of Mass: - This will be different person to person - Does NOT change with movement, always the same in the person Center of Gravity: - this will change with movement of the person - one’s stability is affected by the center of gravity - most stable when:

Center of Mass vs. Center of Gravity Center of mass Center of gravity

Seven Principles of Biomechanics Get into groups of 7 people, number yourselves 1 -7 You will become the expert on your principle You will need a textbook for each group aka 7 textbooks! Pg: 231 -234

Make this table Principle Broad Category Principle #1 Stability Principle #2 Principle #3 Principle #4 Principle #5 Principle #6 Principle #7 Angular Motion What does it state? Terms to understand Examples

Motion Analysis Next class you will be given your take home assignment. You will use notes to work through the following problems and questions for the end of unit evaluation