Mon Prof Augmenté
Muscle pairs at the elbow
When you bend your arm, the muscle at the front of your upper arm gets shorter and fatter. The muscle behind it stretches longer, and its resistance keeps the movement smooth instead of jerky.
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Age 12: open this week
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In the picture
- Short, bulging red muscle on the front of the bent upper arm
- Long, thin blue muscle along the back of the same bent upper arm
- Curved arrow at the bent elbow, marking where the forearm swings
- Short, bulging red muscle along the back of the straight arm, with its blue partner long and thin at the front
Examples
- Lifting a backpack off the floor
- Bringing a cup up to your mouth
Key takeaways
- A muscle can only pull, never push.
- In a pair, one shortens while the other lengthens and controls the speed of the movement.
Carry on in the app
Three questions on this lesson. It has left the free week, so its quiz is for subscribers.
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