Focus on lifting and lowering the hips and chest at the same rate. Activate your glutes and muscles around your shoulders to achieve this hip/chest lift, while keeping the low back muscles relaxed. Here we show the more challenging, single leg version. Click below the video to see a simpler modification.
Pro tip: Concentrate on keeping the hamstrings and low back "quiet." Meaning, don't use those muscles to lift the hips. Hone in on the glutes and the shoulder blades to do the lifting.