Many suffer with lower back pain constantly. Many also have neck pain. Often these problems can be remedied by postural adjustments. You can make these adjustments yourself if you know two things: having a clear image of what it is you are trying to achieve and of how to change yourself to reduce or eliminate the problem. Often that change involves letting go of tension in those painful places.
Change is the key. If the master is holding you and saying to change and you are not having an effect, then you are not changing. Changeability is the term Master George Xu has referred to. If you are alone and working on a form or basic, single moves, or qigong, the movement is defined by change. You are changing something constantly and movement occurs. Many practitioners are not aware of where they are not moving, not changing. And if you are in pain, in the lower back for example, it is a symptom of something not moving, not changing.
To change, qi must flow and for that to happen our minds need to let go of tension. In other words, if we are suffering from chronic pain somewhere in our bodies, part of the dynamic of that pain includes the state of the mind. In my experience one must just do the moves with an intention focused on the relationship of the mind and body, because that is where the answer is.