This pose is commonly practiced during the Sun Salutation sequence, it is a great power pose.
During this pose you will be engaging your abdominal muscles, your biceps and your triceps, and your calf/thigh muscles. So essentially working the whole body.
During this pose there is a tendency to let the lower back drop. To avoid this happening draw the pubis toward the navel. Also make sure to keep the elbows in tight towards your body.
Have fun practicing!
Namaste ✌