In the physiotherapy world, the QL (Quadratus Lumborum) muscles are referred to as the "Grumpy Troll" because they can cause a lot of pain and discomfort in the low back if they have to pick up the slack the glutes and hips should be doing. The QL has two sides (right and left) running from the bottom ribs to the top of the pelvis. If the pelvis is tipped forward, the QL gets shortened and tight (and grumpy!). This class helps to make some space in the low back so that you can banish that grumpy troll!