Coordinating breath and movement is my thing, that's why I always loved Ashtanga Yoga. This pose is from the primary series and I added a simplified version (table top) and instead of holding the pose we move in and out of it with the breath. It a really great one for feeling strength, opening the shoulders and having a sense of control over your movement.
On a physical level Purvottanasa has many benefits: it creates strength in arms and shoulders, improves core strength, improves alignment of shoulders, tones the entire body and is a gentle way to bend the other way (instead of bending forward again). On a mental level it gives a sense of strength and also opennes. It opens the front of the body which brings confidence and steadyness. You can tell, I love this pose and do it in almost all of my classes. Enjoy!