As shown above, a stretch's distance is going to be determined by the mobility of the surrounding joint structures, the presence of scar tissue and / or knots, and the condition of the fascia and
other connective tissues surrounding the muscle.
There are
other smaller muscles, tendons, and
connective tissue that collectively
surround and make up the knee joint but are not relevant for this article to discuss; just be aware of them if you would like to do more extensive research.