MUSCLE CONTRACTION

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TYPES OF CONTRACTIONS…What are the different muscle contractions?

ISOTONIC – WHEN MUSCLE LENGTH CHANGES THROUGH A RANGE OF MOTIONConcentric – Muscle shortening (upward phase in bicep

curl)

Eccentric – Muscle lengthening while tension is developed (lowering weight in bicep curl)

ISOMETRIC – VERY LITTLE CHANGE IN MUSCLE LENGTH WHILE TENSION IS DEVELOPEDExample: Holding a weight stationary (in one place/still)

ISOKENETIC-Similar to isotonic (muscle changes length during the

contraction) where they differ is that Isokinetic contractions produce movements of a constant speed. To measure this a special piece of equipment known as an Isokinetic Dynamometer is required. Examples of using isokinetic contractions in day-to-day and sporting activites are rare. The best is breast stroke in swimming, where the water provides a constant, even resistance to the movement of adduction.

Sliding Filament Theory:-method by which muscles are thought to contract.

At a very basic level each muscle fibre is made up of smaller fibres called myofibrils. These contain even smaller structures called actin and myosin filaments. These filaments slide in and out between each other to form a muscle contractions, hence called the sliding filament theory!

Stretched/Extended Muscle:

Partially contracted Muscle:

Fully Contracted Muscle:

1. CREATE YOUR OWN MUSCLE CONTRACTIONResearch how to show muscle contraction in a visual way using

your own bodies…

2. RESEARCH SLIDING FILAMENT THEORY

Create a PP/Poster/Skit/Speech explaining how sliding filament theory works…

GLOSSARY OF TERMSCreate a Glossary of important terms (key words) at the back

of your book…