when i squat my knees cave in. i can keep them in the proper position for a rep or two but then they start to cave. what exercises help to keep the knees out?
Caving in usually happens when you lean forward too much, sounds like your technique turns to shit after 1-2 reps. I would go lighter weight and work on form.
Could be a couple things. 99% of the time its a form issue. Get a video up of some heavier sets so we can see the problem.
When it isnt technique, it's usually weak glutes (medius) or hamstrings. Tight hip abductors can cause this too.