Master, heres one for you. Find some stairs without carpet, put both feet on the bottom step. Put your Hands on the 4th or 5th step arms straight as the back should be at 90% to the feet. Now drop the Heel on one foot while lifting the Heel on the other with pressure, for 10 secs. Then keep alternating the motion 10 times. You will feel it doing you a world of good . Oh while doing it the arse shouldnt move.