- If you're squatting high bar, switch to low bar because it puts less stress on the knees.
- Practice the "asian squat" stretch. Squat all the way down while keeping your weight on your heels and sit there for a while. Do you have a tendency to want to tip forward onto the balls of your feet when you do that? If so, that's a problem and you need to practice this position more.
- Get a foam roller and foam roll all sides of your legs (especially your IT band) and your glutes before squatting. I have chronic IT band tightness on one side that pulls on something in my knee and gives me pain around the patellar tendon, but it goes away when I foam roll the side of my leg.
- Do lots of warmup reps with bodyweight and/or just the bar.
- Don't stop at parallel. Squat below parallel, until you get a "bounce" from the stretch reflex of your hamstrings. If you stop at parallel, there is shearing force on the patellar tendon as that's where the tension is at the time when you change directions. But if you go all the way down, there is almost no load on your patellar tendon at the bottom when you change directions--the load is transferred to your glutes and hamstrings.
Based on what you've told me, I really think it's likely you aren't squatting down low enough, and that's irritating your patellar tendons.
- If you're squatting high bar, switch to low bar because it puts less stress on the knees.
- Practice the "asian squat" stretch. Squat all the way down while keeping your weight on your heels and sit there for a while. Do you have a tendency to want to tip forward onto the balls of your feet when you do that? If so, that's a problem and you need to practice this position more.
- Get a foam roller and foam roll all sides of your legs (especially your IT band) and your glutes before squatting. I have chronic IT band tightness on one side that pulls on something in my knee and gives me pain around the patellar tendon, but it goes away when I foam roll the side of my leg.
- Do lots of warmup reps with bodyweight and/or just the bar.
- Don't stop at parallel. Squat below parallel, until you get a "bounce" from the stretch reflex of your hamstrings. If you stop at parallel, there is shearing force on the patellar tendon as that's where the tension is at the time when you change directions. But if you go all the way down, there is almost no load on your patellar tendon at the bottom when you change directions--the load is transferred to your glutes and hamstrings.
Based on what you've told me, I really think it's likely you aren't squatting down low enough, and that's irritating your patellar tendons.