Quads on fire at the bottom of the squat

[GlockSquat]

I'm turning 41 in August and have been lifting seriously since 2013. I am 100% natty (and it shows). My most recent PR's are Squat 370 (belted), Bench 300x2, OHP 190, Deadlift 410. After my 370 squat I had some pretty intense pain on the outside of my right knee so I took a full week off where I continued to do LISS cardio and foam rolled. I was feeling good and my knee was not painful at all after that week off. This morning I went in to start my new 5/3/1 cycle with a goal of a 335x5 squat. Well, during my warmups with just the bar I felt a lot of pain in my quads at the bottom of the squat. It's like my quads just tensed up and yelled at me. I continued to warm up with 135, 185, and 225. But the pain did not subside and I didn't want to risk tearing something so for the first time since I can remember I just packed things up and went home. I didn't have muscle pain in the quads the whole week so I'm wondering if the quad pain is tendinitis?I got a deep tissue massage that felt pretty good and I foam rolled my quads and almost fainted from the pain. Maybe that means if I foam roll the pain away I'll be all good?

So now I'm wondering if age has just caught up with me and it's time to do machine circuits! Okay, I'm kidding there (sort of). But I am rethinking my goals and strategy in the gym. I don't want to be in pain and gimpy all the time. I lift to enhance my life, not make it worse. I'm also 6ft1, 240lbs and 30% bodyfat so I know I should trim up a bit too. Any other 40+ lifters have advice? Maybe just do a serious reset with lighter weights? I have been lifting 4 days/week like this:

MON: Squat/rows
TUES: OHP, light bench
THURS: Deads, light squat
FRI: Bench, light OHP.

Any thoughts/advice is appreciated

[GlockSquat]

Decided to just keep doing my program but dropping squats until the quads feel better. Hopefully this isn't the beginning of my downward trajectory to the circuit training machine area of the gym!

[silachoo]

Without seeing a picture it's hard to know for certain but if the pain is localized to an area 1-3'' above the knee cap, you have some tendonitis/Tendonosis of the quadricep muscles.

I have had it and it's a royal PITA. I "cured" it by wrapping the hell out of my quadriceps and doing light 5 second count eccentric front squats. start with 3x5 with 95lbs 3 times a week. If you want to throw in some hack squat or bulgarian split squat that would be useful as well. The key is that the eccentric portion of the lift needs to be very slow and controlled.

I was dealing with this in both quads while trying to hit sets of 5 with 405. Once I dropped the squats for 2 weeks and did the above protocol I resumed squatting, tightly wrapped my quads, and hit some PR's as the pain had gone from a 5/10 to about a 2/10. Today it's a 0/10.