Question: how does the brain send messages to make your body move?

Helen O'Connor answered on 11 Jun 2011:

Different parts of the brain control different things. When we think about doing something, like taking a penalty shot in football, or returning a serve in tennis, the *motor cortex* part of the brain sends a message, like an electrical signal, down the spinal cord (which has thousands of nerve fibres in it) to the arm or leg muscles telling them to move. The motor corext is a part of the cerebral cortex and is responsible for planning and doing motor actions (movement). Different parts of the motor cortex control different parts of the body.

A muscle movement takes about 200 milliseconds (one-fifth of a second) to execute: which is pretty amazing when you think that involves taking in sensory information (things you see, hear or feel), working out what that information means, and then deciding how to respond to that information. So someone throws you a ball, and you need to work out the speed it’s coming towards you, whereabouts it is likely to land, decide where you need to be to catch that ball AND get into position to catch it.

In sport, athletes practise movements repeatedly by doing drills, so that eventually they can do them automatically without even needing to think about it. This is sometimes called “muscle memory”. In sport this is important, as sport performance can actually get worse if you spend too long thinking about a movement.