This principle is now applied in order to get people back to work faster, to resist all sorts of joint and back pain, and to 'fight' aging. This approach inhibits the natural healing process. From the point of view of Daoism this is a form of aggression known as 'attempting to put off your fate.' Eventually it returns (to all of us) and usually with a vengeance. (see chapter 30 of the Daodejing)
I'm not attempting here to accurately represent the methods of physical therapists, a constantly changing field, which is particularly skilled at getting people walking again after surgery. What I am suggesting is that common notions of how healing works can be obstacles to understanding and practicing qigong. A Qigong approach to relieving pain is to increase circulation to any areas of tension so that the possibilities of healing can take place. We stabilize the area with precise and balanced alignment and we practice moving in alignment within a smaller range of motion. In essence, we create a safe enough environment to let relaxation happen, dissolve tension, and let whatever healing can happen, happen.
Pain tells us an injury has taken place. Pain is often associated with tension. If the injury is so serious that no one thinks it will ever heal, than perhaps building strength (ie. more tension and with time, insensitivity) is the best option. It is a situations in which "you are trying to dig a well after you are already thirsty."(Nei jing,Classic of Chinese Medicine, Commentary on the Inner Classic or Chinese Medicine)
On the other hand, if the injury is associated with an area of strength, or chronic tension, and is exacerbated by habitually tense movement or posture, than strengthening more muscles will make the problem worse in the long run. In the short run the problem may appear to go away because it has been obscured...... but this is not true healing.