Unit 1 AOS 1 Flashcards
What are fast twitch muscle fibres used for?
Fast twitch muscle fibres are used for power/strength and anaerobic exercise for fast, forceful muscular contractions.
What are the characteristics of fast twitch muscle fibres?
Fast twitch muscle fibres contract for short periods of time and fatigue easily.
What are slow twitch muscle fibres used for?
Slow twitch muscle fibres are used for aerobic exercise of longer duration at low-moderate intensity.
What are the characteristics of slow twitch muscle fibres?
Slow twitch muscle fibres have a greater capacity to use oxygen, contract slowly with less force, and don’t fatigue easily.
What does the sliding filament theory explain?
The sliding filament theory explains the mechanism of a muscle contraction where proteins (actin + myosin) slide past one another to generate movement.
What initiates muscle contraction according to the sliding filament theory?
A muscle must first receive an electrical impulse from the nervous system to the relaxed muscle.
What role does calcium play in muscle contraction?
Calcium release allows for cross bridges to form between the head of myosin filaments and the actin filaments.
What happens to actin during muscle contraction?
The actin is pulled towards the middle of the A band of the sarcomere.
What determines the force of contraction in muscles?
The force of contraction is determined by how many muscle fibres contract.
What is the role of ATP in muscle contraction?
ATP binds to the myosin heads, causing detachment from actin, allowing myosin to re-attach and contract again.
What is reciprocal inhibition?
Reciprocal inhibition is when a muscle contracts to complete movement, its partner will relax and stretch to accommodate the contraction on the other side of the joint.
What are agonist muscles?
Agonist muscles are those that contract to produce movement.
What are antagonist muscles?
Antagonist muscles are those that relax, allowing for the contraction to occur.
What are stabiliser muscles?
Stabiliser muscles contract to keep one part of the body stable to allow movement to occur at another.
What is the size principle in muscle contraction?
Motor units are recruited for a muscular contraction based on their size, with smaller units recruited first.
When are fast twitch muscle fibres recruited?
Fast twitch muscle fibres are only recruited when large amounts of force are needed.
What is the All or Nothing principle?
The All or Nothing principle states that an electrical impulse of a particular strength is required to cause a muscle fibre to contract.
What happens if the threshold is not reached in muscle contraction?
Muscle fibres will not contract if the impulse does not reach the threshold.
What are the three parts of a lever?
All levers have an axis (fulcrum), a resistance (weight), and a force (effort).
What is the classification of first class levers?
In first class levers, resistance and force are on either side of the axis.
What is the classification of second class levers?
In second class levers, resistance is between the force and axis.
What is the classification of third class levers?
In third class levers, force is between the resistance/load.
What is a lever arm?
The lever arm is the total distance from the axis to the end of the lever.
What is a force arm?
The force arm is the total distance from the axis to the applied force.
What is a resistance arm?
The resistance arm is the total distance from the axis to the resistance/load.
What is mechanical advantage?
Mechanical advantage is the ratio of force arm length to resistance arm length.
What does a mechanical advantage greater than 1 indicate?
A mechanical advantage >1 means the lever system is easier to move resistance.
What is mechanical disadvantage?
Mechanical disadvantage occurs when third class levers cannot lift a heavy load with the same amount of effort.
How do longer limbs affect sport performance?
Longer limbs can produce greater speed.
What are acute injuries?
Acute injuries occur suddenly and usually without warning.
What is an example of an acute injury?
An example of an acute injury is a hamstring tear.
What are chronic injuries?
Chronic injuries are associated with overuse of a particular area of the body over time.
What is an example of a chronic injury?
An example of a chronic injury is shin splints.
What factors can lead to overuse injuries?
Factors include repetition, insufficient recovery time, inappropriate recovery time, inappropriate increase in training load, inadequate footwear, and inappropriate training surface.
