Why would an athlete need to be concerned about a twitch or sustained contraction

why an athlete would need to be concerned about twitches or contractions is because, whenever they perform, and such thing happens, it will most likely distract the athlete, and cause the athlete doing his/her performance to not be as good, and may lead to failure, for example, when someone is running very fast for a sprinting race, and he has a contraction in his leg it will cause him to react by showing signs of pain by slowing down or even tripping and falling, causing him to lose the race.

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