If you want to unleash the longest drives and have a resilient back you must train your joints and tissues to load, store, and recover elastic energy.  You want your muscles  to become like  pulsing springs and your body a controlled whip. This is what generates the most  club head speed.  This is also what makes a resilient back.  I offer a free 30-minute video consultation where I discuss in detail how I will build that into your body tune your body for golf.