Active sitting is where you are sitting on your sit bones not your tailbone, you have adequate lumbar support to facilitate neutral pelvis alignment, and you can align your rib cage directly over your pelvis while elongating your torso. Yes, that sounds like a lot of details but that is why we spend time helping you master this concept. How you sit matters. Your body is a use it or lose it system and you can not effectively use your core muscles when sitting in collapsed and rounded postures. So lets start working on understanding more about that active sitting looks like in the real world.