(I am not a physical therapist.) The ankle part can be trained separately by flexing them, I would believe. If your heels keep raising and you really want to b

(I am not a physical therapist.) The ankle part can be trained separately by flexing them, I would believe. If your heels keep raising and you really want to be able to do it, have someone take a video of your attempt and study where your center of gravity travels. It should move towards the floor in a straight line. Chances are, you are simply not extending your behind outwards enough because there are other parts of your core muscles that are not flexible enough. It's an exercise worth practicing and should be much more popular than the typical "pushups/crunches" routine that many non-athletes do at home. (This is where I will be taken apart by someone who knows more details:) Pushups and crunches train precisely the muscles that will pull your back and shoulders forward. A complex exercise such as squats and a good extension-stretch for your back will go a long way of making office dwellers feel better.