What Is a Hamstring Strain?
Three muscles run down the back of the leg, from the thigh to the knee, that help you bend your knee and extend your hip. As a group, they're known as the hamstring.
A hamstring strain — sometimes called a pulled hamstring — happens when one or more of these muscles get stretched too far and start to tear.
Hamstring strains can be mild, with little pain and a short recovery time. Or, they can be severe and need surgery and crutches for weeks.
