Have you ever tried this pose? It may not look like much, but this is one of those all-purpose poses that tests everything from balance to flexibility to strength. It's intense, so take the back leg knee down to the mat if you want to modify. Or, if you're feeling particularly twisty and want to take it a bit deeper, try opening up the arms or taking a bind. Breathe full, deep breaths and then take it over to the other side.
PS- More yoga poses explained.
PPS- What is the pose that you find most challenging?