Biomechanics Flashcards
What are the 2 different types of forces?
- Submaximal - Less than maximal force, generally used when accuracy is of most importance. (Eg. Putting in golf)
- Maximal - result in perfect force summation, maximal muscles contraction and excellent technique achieve maximal force. (Eg. Kicking for distance)
What is summation of force?
Process that determines how to best use body segments depending on the demands of the task – power or accuracy?
What is simultaneous force summation?
Where all body parts move at the same time to produce a force. Generally used to produce accuracy. (Eg. Dart throw)
What is sequential force summation?
Where body parts are moved in sequence to produce a force. Generally used to produce maximal force in whole body actions such as throwing and kicking. (Eg. Baseball pitch)
Name the 4 principals to produce maximal (sequential) force.
- Stronger and larger muscles are moved first followed by the smaller muscles.
- Sequentially accelerate each body part so that optimum momentum passes from one body part to the next.
- Use as many body parts as possible, so force can be applied over the maximum possible time.
- Follow through is important to prevent deceleration of last segment and safe dissipation of force.
What is the demand of submaximal force summation?
Accuracy
What is the demand of maximal force summation?
Power
What is linear motion?
All parts of a body travel in the same direction at the same speed. (Rectilinear - Movement of a body or object in a straight line trajectory (eg. An ice skater glides along the ice))
What is angular motion?
Takes place when object turns about an axis of rotation. (Eg. Gymnastic rotating around on a high bar)
What is general motion?
Combination of linear and angular motion. The vast majority of human movement in sporting examples is general motion. (Eg. Cyclist)
What is distance?
The path a body follows.
What is displacement?
The direct line from point A to point B. (The way a crow flys)
What is a projectile?
A projectile is any object released into the air.
List 6 factors which affect the flight path of a projectile.
- Gravity
- Air resistance
- Height of release
- Angle of release
- Speed of release
- Spin
What are the 4 different types of spin?
- Top spin
- Back spin
- Clockwise spin
- Anti-clockwise spin
What is gravity and what force does an object accelerate toward the Earth?
Gravity is the force that causes objects to fall to the earth. The force of gravity causes an object to accelerate toward earth at a rate of 9.8 m/s2.
What are the 2 types of balance? Provide an example.
- Static - sprint starts
3. Dynamic - running
List the 4 factors affecting balance.
- Mass
- Base of support
- Line of gravity
- Height of (COG) centre of gravity
What is Newton’s first law?
The Law of Inertia
Explain Newton’s first law.
A body continues in a state of rest or uniform motion in a straight line unless it is acted upon by an external force.
The greater the mass of an object, the __________ it’s inertia.
Greater
What is Newton’s second law?
The law of acceleration
Explain Newton’s second law.
The change of motion is proportional to the force impressed and is made in the direction of the straight line in which that force is impressed
What is the equation of (Newton’s) the law of acceleration?
F=ma
What is Newton’s third law?
The law of action-reaction.
Explain Newton’s third law.
To every action there is an equal and opposite reaction
Provide an example for Newton’s third law (action-reaction).
When a ball is thrown at a wall the force of the action is replicated in the reaction but sent in the opposite direction, thus bouncing off the wall.
