Unit 3 AOS 1: Biomechanics Review Flashcards

Unit 3 AOS 1: Improving Movement Skills and Biomechanical Principles

3.1 - Biomechanical Principles for Analysis of Human Movement

• Introduction to Biomechanics

  • Study of motion and forces affecting the human body.

  • Uses laws of mechanics and physics to improve sports performance.

• Key Concepts in Biomechanics

  • Linear and Angular Movement:

  • Linear Motion: Movement along a straight or curved path without rotation.

  • Angular Motion: Rotational movement around an axis.

  • Newton’s Laws of Motion:

  1. Inertia: An object in motion continues in motion unless acted upon by another force.

  2. Acceleration: The change of motion of an object depends on the net force acting on it and the mass of the object.

  3. Action-Reaction: For every action, there is an equal and opposite reaction.

  • Projectile Motion: The trajectory of an object under the influence of gravity.

  • Factors include height, angle, and speed of release.

  • Levers in Anatomy:

  • Third-Class Levers: Common in human movement, axis, force, resistance, and mechanical advantage.

  • Equilibrium and Stability:

  • Centre of Gravity, Base of Support, and Line of Gravity influence stability.

Benefits of Biomechanics

• Technique Efficiency: Fine-tuning techniques improves performance.

• Injury Reduction: Understanding injury causes leads to better techniques, decreasing injury risk.

• Equipment Modification:

  • Adjustments made to sports equipment (e.g. weight, design) improve performance.

  • E.g. Lightweight gear for juniors, advanced technology in sports (e.g., cricket bats).

• Technology Use: Utilizes tools like bowling machines and video analysis to enhance skills.

3.2 - Motion Mechanics

tTypes of Motion

• Linear Motion: Straight line movement.

  • Rectilinear Motion: Movement in a straight line.

  • Curvilinear Motion: Movement along a curved path.

  • Example: An ice skater gliding or cyclist stopping.

• Angular Motion:

  • Body parts move through the same angle, in the same direction, at the same time.

  • E.g. Gymnast performing a giant circle on the bar.

• General Motion: Combination of linear and angular motion, such as a leg’s movement when cycling.

Measurement of Motion

• Describing Motion: Key terms used are distance, displacement, speed, velocity, and acceleration.

  • Distance: Total path traveled regardless of direction.

  • Displacement: Straight line distance from initial to final position plus direction (vector quantity).

  • Speed: Distance per unit of time (average and instantaneous speed).

  • Formula: Speed = Distance/Time.

  • Velocity: Displacement per unit time and includes direction.

  • Average Velocity = Total Displacement/Total Time.

Force and Torque in Motion

• Force: A push or pull affecting the motion of an object

  • Calculated as F = MA (where M = mass, A = acceleration).

  • Types:

  1. Internal Forces: Originating from the body such as muscle actions.

  2. External Forces: Environmental factors affecting motion like gravity, friction, air/water resistance.

• Torque: Potential to cause rotation, influenced by:

  • Force applied and distance from the axis of rotation (moment arm).

  • Formula: Torque = Force x Distance.

• Factors Influencing Torque:

  1. Amount of force applied.

  2. Length of the moment arm.

Momentum

• Momentum: Quantity of motion, calculated as Momentum = Mass x Velocity.

  • Greater momentum requires more force to stop.

• Conservation of Momentum: Total momentum in a closed system is constant.

  • Collisions can lead to transfers of momentum.

Angular Momentum

• Angular Momentum: Calculated similarly to linear momentum but involves rotation:

  • Angular Momentum = Angular Velocity x Moment of Inertia.

• Moment of Inertia: Resistance to changes in rotational motion determined by mass distribution relative to the axis of rotation.

Impulse and Momentum Relationship

• Impulse: Change in momentum from a force applied over time.

  • Impulse = Force x Time.

  • Important in controlling momentum in sports activities.

• Practical Applications:

  • Techniques in sports like shot put or catching balls can enhance understanding of impulse.

  • Example: Catching a ball with a bend in the knees minimizes peak force and avoids injury.