How is movement controlled?

Our brains are like big computers and are in charge of controlling almost all aspects of how our bodies work and how they move. They store memories and help make sense of all the information we are constantly receiving from the world around us. Our brains are full of nerves which make pathways between each other when we do an action, the more times we do the same thing, the stronger this pathway will become. Different parts of our brains are responsible for different ‘jobs’.

Our brains send messages via nerves to the muscles in our body, telling them we want them to work (to help us move) and how strongly they each need to work to perform the movement we want to do. For more information on how your brain works click here.

Nerves also take information about the world, from all our senses, back to the brain to help it make decisions and also make small changes to our movements to make them become smoother or more effective e.g if you are picking up an egg you don’t want to grip too lightly as it will drop but if you squeeze too hard it will break. Our sense of touch and pressure (as well as what we see) will help give the brain feedback on how well it is doing.

Muscles take action by ‘contracting’ and are attached to bones by tendons. Muscles are made up of thousands of fibres which slide over each other to shorten the muscle when it contracts. Muscles usually work in pairs which have opposite actions, so when one muscle contracts to pull a joint in one way, the other muscle relaxes e.g. your biceps and triceps muscles which help bend and straighten your elbow. To perform complex movements muscles sometimes have to work in groups and be timed well to coordinate

Bones are incredibly strong and help hold us upright. Without our bones we’d look like a lump of jelly on the floor! Muscles pull on bones to help us move. Children’s bones have ‘growth plates’ at the end of them which help them to continue to grow until they reach their adult height but our bones continue to reshape and repair themselves throughout our lives. If we break a bone, special cells form a ‘callus’ which is softer than normal bone and can often appear as a lump around the site of the break. This callus then refines to the shape that is needed and becomes harder over a few weeks to heal the break. For more information on broken bones for children click here.

Joints are where two bones meet and help us bend parts of our body. The inside of a joint is covered by smooth cartilage so that the bones slide over each other easily and the joints themselves are supported by ligaments to help keep them stable.

The fluid in our inner ears gives us feedback as to how our bodies are moving (this is sometimes referred to as vestibular feedback) and our brains use this feedback to help us recognise when we are starting to fall and to help us balance.

Your brain also uses feedback from your vision to help it balance. This is why it helps to focus on one spot on a wall when you stand on one leg and why closing your eyes whilst on one leg makes it so much harder!