We often move too fast, too soon - or not at all - and overlook important modifications our bodies need to maintain capability. It's a common misconception that something is structurally wrong with your body and therefore you can't move in certain ways or engage in certain activities. Really, it's a matter of not overwhelming your tissue's capacity to bear a certain load.
Lots of factors affect our capacity, including (but not limited to): genetics, personal history, stress level, sleep, diet, economic, social, and environmental factors. Other times, pain has become chronic and the nervous system hyper-sensitive. In these cases, turning the volume down on the pain is an important factor in determining the volume, load, and duration of strength training sessions.
And why strength training? Because the body structurally adapts to demand! Which means passive and low-demand (i.e. massage and stretching) modalities do not challenge the body enough to adapt long-term. If you don't move it, you lose it - but that doesn't mean you can't gain it back! 😉