10 Explanations For Those Strange Things You Do All The Time

Why is it that the first thing you do when you hurt yourself (okay second thing after treating everyone to your favourite swears) is shake your hand vigorously? Are you trying to shake the pain out? Cool it down?

Well yeah, sort of.

It is unsure as to whether this is learnt behaviour or an instinctual response, but by shaking your fingers out after shutting them in a door/hitting them with a hammer/getting them caught in the snappy crocodile at the dentist, you could be activating something called "pain gating".

This was a theory put forwards in the 1960s that asserts that non-painful stimuli will block painful stimuli from travelling into the nervous system. Basically a new sensation in the spot where you have hurt yourself will distract the nerves and force them to focus on the non-painful feeling rather than the painful one. It is this effect that is also behind the idea of "rubbing it better" when you smack your shin on the coffee table.

It is all to do with the way your different types of nerves interact with your different types of receptors in the brain. Simply put, you have "large" and "small" nerves, the small ones communicate pain, the large ones communicate everything else. There is gate in the part of the spinal cord known as the dorsal horn which filters the signals coming from these two types of nerve and, if the large ones are activated, the signals from the small ones wont get through.

Shaking your hand basically creates a painless "pressure" sensation due to the G-force the motion creates - pressure takes precedence over pain and, voila, your finger hurts slightly less.