Note: I haven't posted here in eons as I'm working on a book, of which the first draft is now complete! Cheers.
I love the practice of yoga asana, so much that quite frequently I drop in at classes around Portland or whichever town I'm in (Bend, Los Angeles, Encinitas, San Diego, et al). I also attend workshops as often as my time, budget and personal interest allow. For example, in January I dropped in at an Anusara workshop by Sianna Sharman here in Portland.
I do all this that I might hear a teacher's wonderful turn of phrase, watch their presentation, or experience their asana sequence. I also like to simply practice with a group of like-minded people drawn together in mutual interest.
There's a lot to refract back through my own daily practice of Ashtanga Vinyasa. It's compelling to me to see and feel the similarities and differences between systems, and to consider what works for me, what doesn't, and why.
I'm not going to talk right now about the fundamental differences between Ashtanga Vinyasa and other systems; rather, I want to focus on the physical presentation of asanas.
The various "key" teachers of the different traditions all observed common physical tendencies in the people performing asanas, and almost all have responded by systemizing alignment cues as to what's "correct" and "incorrect."
These cues are often quite different, though they're all trying to achieve similar goals, whether it's to protect the lumbar spine, the shoulders and wrists, or the knees.
I've heard several variations of cues for chaturanga dandasana. Chaturanga dandasana means "four-limbed staff" in Sanskrit, though you may take comfort and hilarity in that "danda" has also been noted as slang for penis.
This pose is ostensibly the near-bottom portion of a push-up. The two most strident directions I've received have been:
1.) Keep the upper arm just above parallel.
2.) Never let the upper arm descend below parallel.
One of Ashtanga Vinyasa's greatest strengths is this lack of directives like these, although this disinterest in anatomy can cast quite a large shadow. Still, a one-size-fits-all approach ignores individual anthropometry, or specific bone and joint characteristics.
I've questioned these cues for chaturanga dandasana for a while because I have trained daily with guys who have performed dozens to hundreds of full-range, chest-to-floor push-ups on a regular basis, many of them for at least a decade. Basically I've observed a population of guys doing with no ill effects what many yoga teachers might consider anathema.
During chaturanga dandasana the hand is fixed and can't move, so the pose is what's called nowadays a closed-chain movement. If the pose is done correctly, musculature is triggered sequentially through the legs, trunk, and the scap muscles. The pose should activate and strengthen your serratus anterior; our friend the serratus anterior works with lower and upper trap to upwardly rotate the scapula.
As you lower from the top of the plank down to chaturanga, you'll get both "core" stability training and proprioception as you resist gravity's attempt to pull your lumbar spine or low back into an arch or extension. It's also a great proprioceptive exercise for the shoulder girdle.
Chaturanga dandasana ought to help you gain an active range of motion and make you stronger. These are good things. It can be a great asana to perform to maintain or improve shoulder health.
However, poor movement patterns or weakness in this chain caused by poor scap stabilization can contribute to shoulder injuries.
What do these movement patterns or weaknesses look like? If your hips and low back sag to the floor, you're gonna arch your upper back, and your shoulder blades will hike up and tilt forward. This is gonna impinge your rotator cuff. This is not good. This also means you're using your pecs and not your serratus anterior, which is what we want.
Your shoulder girdle works best when its muscles work together to do their jobs. In the case of the rotator cuff, one of its main jobs is to keep the head of the humerus centered in the glenoid fossa.
I take a simple approach. Do what you need to do to maintain this.
This works best in a Mysore-style setting, where a teacher can watch someone's chaturanga dandasana and then make suggestions tailored to that person's specific needs.
For example, one way to scale down surya namaskar is to use scapula chaturangas, in which the person holds an engaged plank with straight arms. They would inhale and retract the scaps, exhale and protract them, and then, still exhaling, move to downward dog.
Scaling might also mean quarter-chaturangas or half-chaturangas, as the person moves through whatever range they're able to maintain a stable, centered arm position.
It also might mean hands by waist, chest a quarter-inch off the floor — chest below upper arms. Heresy, right? As long as the arm remains centered. Also, hips shouldn't sag, and don't lead with the chin! Meaning the chest would hit the ground first, not the chin or the hips.
Personally, nowadays I like my hands near my waist and my elbows, rather than hugging my sides, out a bit less than 45 degrees (like 30). I also try to actively pull myself down to the bottom, chest almost reaching the floor. I experimented for a while with hands turned to the sides, and also the hands turned completely backwards, which torched my biceps and made for an interesting transition to upward-facing dog.
There's a wide range of possibilities for the way this pose can look dependent on the person's features and their current strength levels.
I teach both led and Mysore-style classes, so I appreciate the need for blanket alignment statements designed to decrease overall risk (and therefore teacher liability), though it's a scattergun approach at best — short on details in order for maximum coverage. The verbal cues in many systems are designed to hit the middle of the class' bell curve. People at either end of the curve are either under- or over-challenged.
A led class is a great way to learn a system and to challenge the dozens (hundreds?) or personal tics and nuances in your personal yoga practice. But to learn one-on-one, pose-by-pose, is really the best, healthiest way to learn Ashtanga Vinyasa, or any system of yoga.