This is one of the best poses for stretching the hips. Many people tend to have tight hips from sitting in front of a computer all day. It will also help increase your flexibility for the splits if that happens to be one of your goals.
Keep in mind that your hands can be wherever you want them to be in this asana, and their location often determines what muscles you are stretching.
If you raise the arms up and tilt them backward, you will bring this stretch into the back as well as the hips. You can also bring the arms down to your sides and behind you a bit to stretch the lower back. The third option is to rest them on the knee in front of you, although you won’t get as deep of a stretch in the hips.
Make sure your front knee is as close to 90 degrees as possible.
Hold for 30 seconds, and repeat on the other side.