squats are very important, take it from someone who is recovering from nerve damage and atrophy below waist. your thighs and glutes control a lot more than you think and it goes down in to your knees which is my biggest issue currently. I could barely walk a few months ago. still have a ways to go. I wasnt really squating much before I went down but I squated fairly regularly in my lifetime. I was never injured or had pains from squating. the key is to have good form and not try to overdo it with the weight. you dont need much weight. like all that 400lbs and shyt is for if you competing. 225 is more than enough.