which muscle flex the hips
Hip flexor strain - aftercare. The hip flexors are a group of muscles that help you move, or flex, your leg and knee up towards your body. A hip flexor strain occurs when one or more of the hip flexor muscles becomes stretched or torn. Hip flexors allow you to bend your knee and flex your hip. Sudden movements, such as sprinting, kicking, and changing direction while running or moving, can stretch and tear the hip flexors.