It’s because stretching does not change the brain. And to change the body we need to change the mind.
Our muscles spindles have nerves that relay information between our spinal cord, brain and muscle. Technically, this function is called the alpha-gamma loop and it keeps us alternating between action and proper resting tone as needed. But stress and injury cause the the feedback loop to get dysfunctional. By allowing gentle muscular “pumping” in proper sequence we get the loop to function correctly again. The muscles change and, more importantly, the mind changes. It sees easier and more supportive pathways in movement and in life.