This warrior 1 variation is something I like to throw into the middle of a vinyasa to get deep in the hips and to open up the chest and shoulders. It's particularly beneficial for people who slouch, or are constantly in a seated position, as their shoulders tend to round. It's also really good for guys who go hard with upper body lifting, as they tend to have really tight shoulders and chest muscles as well.
TIP: Start in warrior 1, and then bring the torso forward. When you can't go forward anymore, lift the arms up. Intend to press the palms together (this will be difficult for people who are really tight in the shoulders and chest), and exhale the shoulders away from the ears. Be really mindful and honest with yourself - this can be dangerous for the shoulders if you're not paying attention. Always work in a pain-free range.
PS- Have a yoga question? Ask it (anonymously, if you like!) here and I'll answer in a future post. Plus, how visualization can help your yoga practice, and a recipe for gluten-free pumpkin pancakes.