Foam blocks are great tools for practicing yoga poses. Use them to develop more flexibility in your hamstrings while eliminating pressure on your lower back. Include this stretch at the end of your workouts when your hamstrings are warmed up.
Place two yoga blocks in front of you and stand upright with your feet in a split stance. Position your right leg forward between the blocks and your left leg approximately 31/2 feet back. For added stability, turn your back foot out slightly. Inhale with your hands on your hips, lift your chest and relax your shoulders down away from your ears.
On an exhale, bend forward at the hips, maintaining a long spine. Rest your hands on top of the yoga blocks. Inhale, lengthen the crown of your head away from your hips. Pull your abdominals in to support your spine. Pause for 10 to 20 seconds, feeling the stretch in the backs of your legs. Return to your upright start position, switch legs and repeat with your left leg forward.
Source : The Losangles Times