(KAIT/NBC) - Hamstring injuries can hit a professional athlete or even your daily runner.
Muscle strains are common and can happen to anyone during physical activity.
Hamstring muscles run down the back of the thigh.
This large muscle can be pulled, partially torn or completely torn.
You'll notice a sudden, sharp pain in the back of your thigh, and in some cases, swelling and bruising.
Doctor Patrick McCulloch says an MRI can help doctors grade the injury on a scale of one to three.
Recovery for a grade one means stretching and gradually going back to normal activity.
Tear grades two or three can take weeks with more intense treatment, but typically not surgery.
"One of the most common problems with this is if you try to go back too early, you can re-aggravate that injury," Dr. McCulloch said.
Dr. McCulloch says frequent stretching will prevent hamstring injuries.
For more information on hamstring injuries, click here.