I can only find one true quad isolation exercise and that's the leg extension exercise. My issue is I have a glute medius strain, which only seems to effect when I'm squatting, whether that's one leg or both. I can only squat maybe 20 degrees at most before I feel mild tension, and naturally the more I go the worst it feels up to 90 degrees. Since it can take 4-6 weeks for a strain, I'd like to not lose all my progress, as I seem to feel fine doing RDL's. I also feel fine doing standing abduction machines and the like. It's the "driving through the heel" maneuver from knee flexion that seems to cause a lot of pain. So I'm wondering if all I have available to me is leg extension machine for the next 6 weeks to continue making progress?