Hamstring muscles are prone to injury from a number of causes, and injury can cause anything from mild discomfort up to severe pain. Sometimes people can even find themselves unable to walk properly after a strain has occurred. Incidents often involve a tear in one or more of the muscles that help to bend and flex the knee and move the thigh backwards at the hip. It is rare that a hamstring injury occurs as a result of contact, with the majority of strains happening during exercise. Instead injuries most often occur during rapid movements of the leg, resulting in a sharp pain whenever you either straighten your leg or contract it against resistance.
It is common for hamstring muscles to become injured during rapid exercise purely because of the actions involved when carrying it out. As the shin bone swings out, these muscles try to decelerate this rapid movement. At this point they are at their maximum length and at their highest level of effort, vastly increasing the likelihood of injury. As would be expected from an injury developed through rapid leg movement, strains are felt most often by professional athletes such as sprinters or hurdlers. However, sporting activities such as rugby and football can often be found to be a cause.
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