Did you know: Muscles contract, and relax…

Some muscles in our bodies are attached to bones, and when they contract, the bones move. That’s how you can eat delicious food…just lifting food from your plate, to your mouth, requires your ‘bicep’ to contract.

‘Contract’ means the muscle fibres (the stuff that makes up the muscle) stack up and become shorter. When the bicep shortens, it lifts your hand towards your face!

Every time a muscle contracts, another muscle relaxes. In the case of your biceps, it’s the tricep that relaxes when you bring food from the plate to your mouth. They work together in pairs!! They’re a great team, just like you and your friends are.

So for me to eat my healthy food, which fuels my movement, my brain has to send a signal down to my arm, telling the bicep to ‘contract’ (shorten), and the tricep to ‘relax’ (lengthen). Clever brain!!

Have a go with this action, to help you understand:

Look at a partner’s arm when they pretend to eat something, can you see their bicep contract, and their tricep relax?

You can strengthen your biceps and triceps by doing pulling and pushing movements. Give this a go…

Stand behind your chair, then squat down to pick it up safely. Now, standing with long arms, holding onto your chair, bend your elbows to lift your chair up, and then lower it down again. When you do this, keep your tummy gently ‘pulled in and up’, and your knees bent. Do this five times…you’ve just pulled the chair towards you using your biceps!

To use your triceps, sit on the chair with your hands holding onto the seat, just under your legs. Scoot your bottom off the chair, so you are still holing on with your hands, but your bottom is just in front of the chair. Now bend your elbows and lower yourself down, then push up again by straightening your elbows. Do this five times…you’ve just pushed yourself up using your triceps!

Do you know the names of any other muscles in the body? What actions can you do to make them contract? Which muscle has to relax in order for that one to contract?

Our heart is a muscle as well…does that means it contracts too? Find out what you can and tell us about it on the blog!

Captain Kinetic

Enjoy contracting and relaxing!

Captain Kinetic 🙂




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