What is with all the leaping about, anyway? My arms are tired! My wrists are sore! My shoulders ache! Ashtanga has so many vinyasas!
The Sanskrit word 'vinyasa' has become short-hand for 'jump back into a push-up,' and truly Ashtanga has more of this movement than any other style of yoga.
However, I'd just like to remind you that this is not merely or only all that it means...
Esteemed vini yoga teacher T.K.V. Desikachar suggests that the word 'vinyasa' is the result of two words: 'nyasa,' which means 'to place,' and the prefix 'vi,' which he translates as 'in a special way.'
His understanding of 'vinyasa' is that it means 'to put or place in a special way.' In our case, we are putting and placing our bodies in consonance with our breath.
Desikachar goes on to say that "vinyasa ... tells us that it is not enough to simply take a step; that step needs to take us in the right direction and be made in the right way."
I bring this up just to remind you that there is a larger, grander understanding of the word 'vinyasa.'
I encourage you to approach Ashtanga as a breath-body movement practice. We use jump-backs, the push-up, and plank positions as tools or expressions of that practice --- these tools as demonstrated on YouTube, or even the person on the mat next to you, may not be appropriate for you at this time.
Your practice will ebb and flow as your conditions changes (as they must). This means your ability --- or even your interest! --- in leaping (or lumbering) back to push-up position will change as you continue to practice. You may modify them, reduce their number, or even eliminate them altogether.
In 2012, as I was wheeled on a gurney from the ER to have surgery to piece together my foot, I practiced Ashtanga by breathing in and shrugging up my shoulders, then breathing out and shrugging my shoulders down. It helped calm me down a little, and helped me appreciate the panic and fear I was experiencing.
So I suggest that you can still practice vinyasa --- and Ashtanga --- as long as you practice allowing movement to stem from breath.
I have done this practice since 1998, and in that time have seen dozens (hundreds?) of variations of Ashtanga, as done in hospital beds, by amputees, and even (on YouTube) by a guy in a cast with a broken femur.
So if you have questions as to how to modify for your needs, please ask!
Jason owns and directs Portland Ashtanga Yoga.