Modern research on ergonomics (the interaction between people and their work environment) is confirming what meditators have known and expressed for thousands of years: sitting with your legs and torso at 90° is mad difficult.
Ironically, even though most of us have spent tens of thousands of hours in chairs, we don’t exactly get any “better” at sitting with age. If anything, our sitting posture tends to deteriorate over time. This is because while sitting at 90° has become normal, scientific research shows that it is not natural.
Studies done in 1999 and 2007 show that sitting at an angle (between 110°-135°) protects the discs of the spine from compression damage. Participants in the study also found this angle most comfortable. In my practice, I students tell me they don’t feel the compulsion to slump as strongly when they are permitted to sit in this more ‘open’ position.
You can achieve this angle one of two ways – lean far back (which is tough to do while meditating) or drop the legs away. Which brings us to these classical meditation postures:
According to Prof. of Architecture at UC Berkeley, Galen Cranz (author of “The Chair”), “In classical chair sitting, the upper leg is at a right angle to the spine; but when this angle is opened wider (in other words, when the thighs slope down toward the floor), the muscular work of sitting upright is distributed most evenly throughout the spine, front to back and top to bottom.”
This position is closer to perching than what we normally think of as sitting. Yet, our body weight can still be completely supported by our sit bones and legs. In an office chair, the legs can spill away like as in the above photo. But for the meditator who is closer to the ground, one must consider the effect of additional pressure on the knees. You can add padding to your kneeler, or use a blanket. If you sit on a zafu, just place cushions under your knees.
As a tall person I have to use a few cushions to raise my seat high enough off the floor to open up my hips greater than 90°. If I’m sitting for any length of time, I use these cushion supports under my knees to reduce pressure on the knee joints. During retreats I sometimes feel more like a sultan than a humble meditator. But taking care of oneself (and being willing to look odd in the process) is just part of that generosity.