Lloyd Dean

Muscle Contraction

AimsBy the end of the lesson you should be able to:

Describe the all or none law of muscle physiology.

State muscle fatigue and oxygen debt in relation to muscle contraction

List the types of muscle contraction

Describe agonists, antagonist, synergists and fixators applied to a range of exercises.

All or None LawTo fire a gun there must be

enough force to pull the trigger

If you pull the trigger harder the bullet does not travel faster!

A contracted muscle receives a nerve impulse either completely or not at all

The action potential (Nerve impulse) is at full strength or not at all

This is the All or None Law!

Muscle Fatigue & Oxygen DebtHow do these both impact the muscle contraction?

If no ATP is available no contraction will take place

If you use more oxygen that is taken in through the lungs then there is a deficit of oxygen

This can make the blood PH level rise, and become acidic (Commonly know as an increase in Lactate acid)

This is a by product of exercises without oxygen, or anaerobically

Antagonistic Pairs

Biceps – Prime mover

Triceps – Antagonistic

This muscle determines the movement of an action –by Contracting

Biceps – Antagonistic

Triceps – Prime Mover

This muscle works with the prime mover but creates an opposing action – by relaxing

Agonist, Antagonists and.......

Synergists FixatorsHelp to steady the

movement

In biceps curl the brachialis helps the action

Assist in stabilising the origin of the agonist to ensure movement occurs

In biceps curl the fixators would

Muscle contraction

Three types

Isometric

Concentric

Eccentric

Isometric Contraction

Muscle stays the same length during Contraction or when the activity is being carried out.

Name a sport/activity where isometric contraction occurs?

Concentric Contraction

This where the muscle shortens when performing an action

Name a sport/activity where Concentric contraction occurs?

Eccentric Contraction

Where the muscle lengthens under tension – ends of the muscle move further away during an action

Name a sport/activity where Eccentric contraction occurs?

Muscle Tone

Muscle tissue never really relaxes and is in constant partial contraction – this gives muscle its shape or tone.

Review of aimsYou should now be able to:

Describe the all or none law of muscle physiology.

State muscle fatigue and oxygen debt in relation to muscle contraction

List the types of muscle contraction

Describe agonists, antagonist, synergists and fixators applied to a range of exercises.