Stability Ball Training: Abs & Back With Robert Sherman This creative video addresses the physiological, biomechanical and kinesthetic awareness principles, which form the foundation in training the abs and back on the ball. To access this content, you must purchase Stability Ball Training: Abs & Back, OnDemand Monthly Subscription Payment Plan, OnDemand Annual Subscription, OnDemand Monthly Subscription, OnDemand 6-Month Subscription or OnDemand 2 Year Subscription or log in if you are a member.