Much of the hands on work that I do involves manipulating and mobilizing restricted tissues. The targets may include joints, muscles, fascia, tendons and ligament, and scar tissue. A runner complaining of low back pain my have normal movement in their back (and often too much movement in their back) but extreme stiffness in their hamstrings. So, treating the low back alone may not address the real limitation.
Similarly, a person with neck pain may have normal movement in their neck but extreme stiffness in their mid back just a bit lower that never bothers them. In many cases, I’ll mobilize something seemingly unrelated to your pain to remove the stress from the painful tissue. Often the tissue that’s hurting is overloaded and moving/working too much and it’s neighbor is not pulling it’s weight during movement. If we mobilize the stiff stuff, the painful stuff usually feels better. And we don’t need to treat the pain!