Tightness in the sides of your lower back? I’m sure you have already stretched or massaged the lower back, and if the pain keeps coming back, then it’s time to implement some strength. The butt walk is a simple move that can be modified. You don’t need to hold anything overhead. You can keep your knees bent. When you have the knees bent OR straight, the goal is not to lift the leg upward with your hip flexors; you are working to lift your leg with your lower back muscles by hiking the hip upward