Muscles and movement
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Summary
Muscles and movement
In a nutshell
Muscles are an essential part of your body and the muscles attached to your skeleton help you move. In this summary, you will learn how joints, tendons and muscles allow you to move.
Bones and muscles
ligament | A body part that connects bones together. |
joint | The point where two bones meet. |
tendon | A body part that connects muscle to bone. |
Muscles and movement
Muscles are made of cells that contract (shorten) and produce movement. When a muscle contracts, it pulls on a tendon which causes the bone to move. This only happens if the bone is part of a joint connected by a ligament.
Muscle pairs
Muscles can only pull in one direction so they must work together. One muscle contracts pulling the bone whilst the other relaxes and lengthens. To reverse the action, the muscle that was relaxed then contracts to pull the bone in the other direction.
Note: The muscle pairs must be of the same type. So, the heart is a muscle that pumps blood around your body. But this muscle won't work in a pair with your biceps because it is made of a different type of muscle.
Example
Triceps (1.) and biceps (2.) are an example of two muscles that work as a pair.
Movement | Bicep movement | Tricep movement |
| Lifting the forearm | Contract | Relax |
| Lowering the forearm | Relax | Contract |
 |  |
FAQs - Frequently Asked Questions
Why do muscles work in pairs?
Muscles can only pull in one direction so they must work together. One muscle contracts pulling the bone whilst the other relaxes and lengthens.
How do muscles help you to move?
Muscles are made of cells that contract (shorten) and produce movement. When a muscle contracts, it pulls on a tendon which causes the bone to move.
What is a joint?
A joint is the point where two bones meet.