I supplement with ankle, hip, and back mobility work. Motion is Lotion!
I like this advice. I make sure not to skip leg day and squats and deadlifts have helped a lot. I notice my knees start hurting when I *don't* exercise them. And, squats don't have to be super heavy powerlifting moves either. You would notice a difference with just body weight or 'goblet squats' with dumbbells.
+1. Strong glutes are associated with less knee pain. It has something to do with the IT band. Also, a strong vastus medialis (that muscle right above your knee) is associated with less knee pain. Leg extensions can help this, but unfortunately people with weak vm get pain when doing leg extensions, a classic catch-22. Squats will help the vm also, but not as much as leg extensions.
Remember what Tim Noakes says in "Lore of Running": the #1 ergogenic aid of all time is physical training.
"Thy righteousness is like the great mountains." --Psalms 36:6
2 - (Don't laugh) 10 minutes of squats a day on a DB Method machine (yes, the butt machine), which is an angled squat machine with a seat that shifts your weight back onto your glutes. This takes the weight off your knees and lets your hips and glutes do the work, and the high volume that's possible strengthens your hips. If I tried to do ten straight minutes of traditional squats, my knees would throw a fit, but using the machine takes away that limitation. You can add a weight belt for more resistance. I also do traditional squats with dumbbells as part of my weightlifting routine, but in lower volume - just three sets of 12 reps. I used to do super-heavy squats on a rack back in the day when I was a gym rat (over 400 pounds when I trained with Mr. Southern California, Paul Harris, back in the 1980s), but no time for that these days.
I wouldn't laugh, having a strong butt is important, but a lot of people work on it for the "wrong" reasons, and so it has become a joke
Those who travel to mountain-tops are half in love with themselves and half in love with oblivion
What ya wanna do is not so much build up your butt muscles to incredible proportions, but to just make sure you're actually utilizing them in the right proportion to your other muscles. They get, in a sense: lazy, and don't fire when they should and that causes muscle imbalances, tightness, pain - lots of stuff to fix. So if you get a 'script' for a PT to work on that, they're not going to have you do hyper weighted glute bridges, but may get you on a physio ball or do bodyweight glute bridges for you to learn how to use your butt. You just may need to work on your pelvic tilt.
They may be weaker than they should, but once they learn how to work correctly, just doing the activity - like hiking, should be enough to strengthen them. Kinda similar on how bad form when lifting heavy stuff can lead to pain and injury. It's easy to lift a light box with just using your back, and you get used to be able to to do it, until you try to lift something heavy and you just don't actually have the functional movement pattern to do it safely. And that's true even if you have the concept of what a deadlift is - knowing and doing is still two different things. It sounds crazy, but the same thing can be said for simply walking, especially if you're used to sitting 8 hours+/day.
Lots of tightness and pain can come from muscle imbalances, like between your lower back and your front core muscles, or your hamstrings to quads. I think of mobility work as just fixing these muscle imbalances, rather than thinking of it as stretching, which is trying to physiologically change how deep you can pull a muscle in extension. Like my shoulders slouch forward, but stretching ain't going to do much - it's just my back muscles are strong, and my chest is really weak (cause I climb, and don't do much um: dipping or benchpress or whatever). I'm lined up for a shoulder injury for sure. My lower back hurts more than I'd like to admit, but it's probably from my hip's being "tight" (or really: weak), since riding a bike and running aren't really working my legs on my planes of motion. The job of my hips is taken on by my back - which is bad at it, and it's cranky.
Or take my terrible ankle dorsiflexion. I've stretched it all it's going to go, but what may help me more is just working on my tibialus stretch, which is what actually pulls my foot towards my shin. It's not weak per say, but compared to my monster calves from cycling and hiking up things, it's just can't keep up. Strong tibialus muscles also help with keeping shin splints away, and feeling fresh after that long slog downhill so worth a look into working on. Easy and quick to do,
(sorry for the internet black hole of Kneesovertoesguy you'll fall into)