Place your foot on top of a ball.
Maintain the lordotic curve in your lower back and slowly flex forward. Focus on moving your navel toward your thigh. As you flex forward, press your heel into the ball with approximately 30-percent pressure. Hold this contraction for five to six seconds, relax the stretch for two seconds, and then proceed to the next stretch. This system utilizes the PNF method of stretching, which basically implies that if you contract a muscle, allow it to relax, and then stretch it again, the subsequent stretch will be greater. You can also focus on the different heads of the hamstring by pointing your toes in or out.
Perform three to five static stretches of 20 to 30 seconds each, or two to three sets of three to four PNF stretches each.