The Single Leg Deadlift is one of the most effective exercises you could ever perform. It essentially teaches you how to "hinge" from the hip and load  up the muscles on the backside of your body. (Glutes, Hamstrings, Calves, Low Back Muscles). Done properly it will help you learn how to move from the hips while simultaneously improving your posture and movement habits. Most people end up moving from the low back too much and this can cause low back pain as well as upper back and shoulder pain. The Single Leg Deadlift done well can correct many asymmetries and weaknesses in your body.