Yoga has been very beneficial in improving my range of motion and flexibility, as it will for all people. However, forward folds of any kind are difficult and sometimes painful for me due to irritation of the ischial tuberosity (sit bones) from Ankylosing Spondylitis. I will probably never be able to touch my toes in these poses. When I am in periods of little pain, I forget that I have this auto-immune arthritis, and often quit taking my Sulfasalazine, because - "I must be cured!". (I have the same mentality about my allergies - no symptoms - "I must be cured"). So, as we always do in Yoga, I honor my body, and if it says, "Nope, not going there today," I take the poses in a more gentle fashion, only going to the edge between ease and effort, or comfort and discomfort. The important thing is to listen to your body and keep practicing.