That is the question.

Usually, it is a wonderful thing to study with different teachers and get a different perspective on your yoga practice. But sometimes it can be downright confusing when you seem to be getting opposite instructions from different teachers. One of the confusing instructions that come up is about the pelvis/tailbone. Do you tuck it, or don't you, and if so, when? If you come to my classes on a regular basis you know I tell you not to tuck the pelvis in mountain pose and seated poses (to clarify: tucking the tailbone moves your back towards cat pose and rotates your pelvis backwards). But I am sure you've met teachers that tell you the opposite. (One thing to keep in mind is that many yoga teacher have a background in dance and have been indoctrinated with tuck, tuck, tuck! )


A 5 minute bit of research in my own library has B.K.S. Iyengar ('Light on Yoga') saying to lift the backs of the thighs in mountain pose (this tilts the pelvis forward) and Judith Lasater ('30 Essential Yoga Poses') urging us NOT to tuck the tailbone. On the other hand, Erich Schiffman ('Yoga: the Spirit and Practice of Moving into Stillness') and Patricia Walden ('The Woman's book of Yoga and Health') tell us to make sure to tuck the pelvis.

Knowledge is not a static thing. A few years ago I don't think I had a firm opinion on tucking or not tucking, I may even have leaned toward tucking. But as I read more, and took more classes and tried things out, I have landed firmly with the non-tuckers. One of the books that really made the point for me is Esther Gokhale's Eight Steps to a Pain-Free Back. Whether it works for your back or not, the first chapter makes an excellent argument for not tucking your pelvis, showing how pulling the tailbone under puts stress on the wedge shaped disk between your sacrum and your spine, leading to pain and herniated disks.

Leslie Howard also stressed the importance of untucking for the pelvic floor muscles in her recent workshop. A tucked pelvis does not only lead to permanently shortened PF muscles, it also places the pubic bone in a position where it no longer serves to hold up your internal organs such as your bladder and uterus. That burden is then placed on the gripped and weak pelvic floor muscles, which can lead to prolapsing of these organs. Another pelvic floor expert chimes in here on this blog (scroll down a bit for the bit on posture).

P.S. If you have lordosis (excessive curvature of the lower back, also called swayback), you've probably been told that you should tuck to counteract the excessive curving. The swayback, however, is in most cases not caused by a pelvis that is rotated forward too much. It is usually a combination of a tucked pelvis, locked knees, hips that push forward and a lifted ribcage. After a few years of standing that way you have created short back muscles and weak abdominals. Tucking your tailbone in this case is not going to solve your problem, it's like putting a brace on an already weak knee. What you need is lengthening of your lower back muscles, active abs, a rotation of the ribcage and a level pelvis (which will feel like a forward rotation to you initially!). In order for this to become comfortable you'll have to put in time lengthening your hamstrings and back muscles, and strengthening your glutes and deep abdominals.