Tony, great question. The theory behind putting the band in both directions is to work on both physiology and accessory movement. The physiologic movement is the true movement you see at the joint, i.e. shoulder flexion, hip extension etc. Accessory movements are what we call roll, glide and spin. They happen at the joint involuntarily. It’s important to try and work on both aspects of the overall joint biomechanics if they are restricted. I hope this helps.