Squats are useful, but knee strength often needs a wider approach. Best Variations: Short-range split squats, split squat holds, slow-tempo split squats. Low Box Step-UpLow box step-ups build knee strength through the same pattern you use on stairs and curbs. Train both sides evenly: Split squats, band walks, and step-ups help each leg rebuild its own strength. Knee strength builds best through steady, controlled work.