• Question: how and why do cramps occur?

    Asked by charlieallen to Helen, Jenni, Mark, Martin, Stu on 17 Jun 2011. This question was also asked by grococka09.
    • Photo: Mark Burnley

      Mark Burnley answered on 15 Jun 2011:


      The answer is we don’t really know! We think it might have something to do with receptors in the muscles and joints not giving the brain the right information, causing the muscle to contract when it should be relaxed. These receptors are really important because they prevent the muscle from over-stretching or over-shortening and damaging itself, but sometimes they go a bit wrong. This explains why stretching a muscle can relieve a cramp: what you are doing (we think) is giving the receptors more information so that they figure out that the muscle is contracting when it shouldn’t be!

      Have you ever noticed the OPPOSITE of a cramp? This is even rarer, so rare in fact that you might not even believe it exists (there is certainly no scientific evidence of it), but when I’m running, every once in a while my leg feels like it is going to collapse when I step onto it. I have always wondered what causes this, and my best guess is that it has something to do with these same receptors not helping the muscle contract when they should. It feels a bit like pushing a door somebody else has already opened for you. When this happens and I’m running it looks like I’m pretending to fall over, which looks pretty stupid!

      There is of course the theory that cramps are caused by lactic acid (it doesn’t), but I covered this in another answer: http://bit.ly/iLyupv

    • Photo: Stuart Mourton

      Stuart Mourton answered on 15 Jun 2011:


      I don’t think i have much to add to Marks answer really. It can be a real problem though, as you will often see players having to stretch out lots when games go on longer than normal. Extra time in football is a good example. It is pretty obvious too that it is an afliction that happens to almost all players and there’s nothing you can do about it. You’ll often see team mates and sometimes even opposition players helping each other stretch out their legs if they get cramp. It’s pretty painfull!!

    • Photo: Helen O'Connor

      Helen O'Connor answered on 17 Jun 2011:


      Thanks Mark: this is definitely not my area and I don’t know alot about physiology. I have worked with golfers who suffer from something called the “yips” where their hands go into a sort of spasm which stops them taking shots (this problem can get quite serious and cause people to retire from golf). Darts players can also suffer from something similar.

      There are several expanations for the yips, some say it is just a psychological problem, caused by anxiety, but other research has shown that in some ways, the “yips” is similar to the muscle cramps that writers or musicians can get in their hands. We still dont know how to stop cramps though!

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