Muscle contraction types and all or none law

1. Lloyd Dean
Muscle Contraction

2. Aims
By 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.

3. All or None Law
To 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!

4. Muscle Fatigue & Oxygen Debt
How 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

5. 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

6. Agonist, Antagonists and.......
Synergists Fixators
Help 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

7. Muscle contraction
Three types
Isometric
Concentric
Eccentric

8. 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?

9. Concentric Contraction
This where the muscle
shortens when performing
an action
Name a sport/activity where
Concentric contraction occurs?

10. 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?

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

13. Review of aims
You 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.