Step feet into 3rd or 4th row of boxes with heels on the line
Lower down into semi-squat, pushing low back, hips & shoulders into wall
Hold for 30-secs then lower a few inches deeper and hold again for 30-secs
Lower a few inches & hold for 30-secs once or twice more, then return
If you feel excess pressure in your knees step feet slightly further away from wall to reduce angle at hips & knees