Jason Schramm of Detroit Yoga in Royal Oak MI discussing details of Chaturanga Dandasana.
That so many people do not follow the steps mentioned in this video, is why I have little hair left on the top of my head, as it has been pulled out! :)
Specifically, the modification of dropping the knees until one develops the strength to move through this transition smoothly. I suspect it's a pride thing. They don't want to appear weak by using the knees to do a push up. Although this is rarely, if ever admitted.
Not to get lost down the rabbit hole of psychoanalysis, I'll just stay on point with the details mentioned in this video. If you come to Ashtanga Vinyasa Yoga practice, like many do, being a little upper body strength challenged, be patient, be humble, be playful. If you practice consistently, there will be improvement sooner than you might think.
But please don't let fear of looking foolish (pride), keep you from practicing! As I watch my parents get older, I am constantly reminded of the value of maintaining the skill of being able to pick one's self up off the floor, and what happens if you let it go.
Get to class. Surround yourself with others who are working on what it is that you want to achieve, as well as inspirational role models, who are where you want to be.
Jason Schramm of Detroit Yoga and Students demonstrating parts of Ashtanga Vinyasa Yoga Practice.