The deepest version of this pose should only be practiced when your muscles are very warm. Cold hamstrings are prone to injury. Do sun salutations until you are hot and sweaty, and bend forward with slightly bent knees. Do not push yourself beyond your limits unless you would enjoy having a torn hamstring!
Stand tall in mountain pose, with your feet hip distance apart, toes pointing straight forward. Engage your quadriceps by raising your kneecaps and squeezing your inner thighs towards eachother. Bring your hands to your hips and tilt your pelvis back slightly as you hinge forward. Keep your lower back flat, maintaining the lumbar curve to avoid strain in that area. Lengthen through your spine while lifting the sitting bones to the ceiling. Continue to hinge forward from the hips until you can’t keep a flat back any longer. Drop your hands to your thighs, shins, ankles, or the floor. As you inhale, lift your sitting bones higher, flatten your back and, as you exhale, bring your chest towards your thighs. For a deeper stretch, grab onto your big toes with your first two fingers and bend your elbows to pull you closer to your thighs. You will feel an intense stretch in your calves and hamstrings, with no strain in the lower back. Let go of your head and neck and continue to inhale and exhale through the nose.
