Knee hypertends very often hurts but pain subsides shortly after i have a physical next week but i need her to sign off for softball.do i tell her?

Yes: If your knee hyperextends you may have one of the hyperdistensibility syndromes which can affect other joints as well. And in any case you should have a physical therapist show you proper muscle building exercises and possible splinting during sports. The exercises will build muscle and ligament and tendon strength to protect your joints. An arthroscopy means an Orthopedist who can refer you.