“This exercise is designed to both assess right and left contribution of the hip hinge under an asymmetrical load and increase single leg contralateral deadlift strength.” – http://www.functionalmovement.com/exercises/deadlift_single_leg_single_arm_with_one_kb
The exercise is unique in that it allows you to fully appreciate the beauty of learning how to stabilize on one leg, while training each side of your body without favoring or over-compensating.
If you are like me, you may over time have become more quad dominant. This is a great exercise to help teach volleyball players to fire their glutes and not their quads.
Warning, if you have never done them you will be amazed at how difficult it is and how sore you will be in the days to follow. Don’t do this late in the week if you are playing a tournament on the weekend!