It's All One
Solving any problem begins with a critical step: identifying what the problem actually is. In my world, this means arriving at the correct "mechanical diagnosis".
A mechanical diagnosis is fundamentally different from a medical diagnosis. In medical diagnostics, the problem is usually either an abnormality with your anatomy (like a plugged artery or broken bone), or an invasion by "bugs" (like a staph infection or a virus). Usually, you can identify the former with some form of imaging, and the latter with some form of blood test.
Mechanical diagnostics are an altogether different problem. Every human motion, (taking a step, reaching for a jar, etc.) has a pattern to it, and the whole body is involved in that pattern. Each body part has a roll to play. For a simple illustration of this, stand up and try to move your ankle, or your knee, or your hip on one leg without moving either of the other two joints. Go ahead. I'll wait.
What you'll see is that it is impossible to move any joint in the lower limb without moving the other two. This motion tracks all of the way up the spine to the skull. Every region has a roll to play. This means that, if any region cannot fulfill its roll, the pattern gets shifted and other parts get overloaded. Sometimes the overloaded parts cannot accommodate the increased load, and the tissue starts to break down. This causes local pain and inflammation, often severe enough to limit the activity. This pain is often labeled with a medical diagnosis (Achilles tendonitis, for example). The problem, however, is the altered pattern that caused the overload. Sticking with our Achilles tendonitis example ( the preferred term is "tendinopathy", but let's save that for another time) the mechanical problem may be a stiff ankle joint, a stiff hip joint, weak hip musclulature, a single leg dominant gait pattern, a stiff great toe, or any number of other factors, alone or in combination. Failure to identify the problematic pattern leads to failed, or at best, incomplete interventions.