Biomechanics Flashcards
Describe Newton’s Three laws of motion
Law of Inertia: “A body in motion tends to stay in motion and a body at rest tends to stay at rest unless acted upon by an external force.”
kettlebell resting on gym floor vs curling rock sliding down ice. Both will remain in their state until acted upon an unbalanced force.
Law of Acceleration: “F=ma”
E.g Hitting a basketball vs hitting a baseball
Law of Reaction: “For every action, there is an equal and opposite reaction.”
Eg. The action of pushing against the court floor leads to a reaction force—that is, the floor pushing back—and, ultimately, the athlete’s body leaves the ground.
Principle 1
1 Stability - The lower the centre of gravity, the larger the base of support, the closer the line of gravity to the center of the base of support, and the greater the mass, the more STABILITY increases.
Principle 2
2 Maximum Effort - The production of maximum force requires the use of all possible joint movements that contribute to the task’s objective.
Principle 3
3 Maximum Velocity - The production of maximum velocity requires the use of joints in order- from largest to smallest
Principles 4
4 Impulse - the greater the applied impulse, the greater the increase in velocity
Principles 5
5 Direction of force application - Movement usually occurs in the direction opposite that of the applied force
Principles 6
6 - Angular motion - Angular motion is produced by the application of a force acting at some distance from an axis, that is, by torque.
Principles 7
7 Angular Momentum - Angular momentum is constant when an athlete or object is free in the air
First Class lever
Eg Head Movment
Axis(Fulcrum) in the middle- neck
Resistance(Load)- head
Force(effort) - neck muscle
Second Class lever
E.g Plantarflexion of foot
Axis(Fulcrum) - toes
Resistance(Load) in the middle - body weight
Force(effort) - ankle pushing up also quad muscle
Third Class lever
E.g Bicep Curl
Axis(Fulcrum) - Elbow
Resistance(Load) - The dumbbell
Force(effort) in the middle - biceps muscle
