I have a very bad left knee, that has been bothering me for the last 20 years, so obviously my leg development has always been lagging.
However I have always been somewhat suspicious about the “don?t squat” tales from a lot of people.
I think the best advise I ever had was from a doctor telling me that “if it hurts bad don?t continue, if it hurts good by all means continue”
Recently I have changed leg training after reading esp. Mike Boyles articles.
So for now it is mostly front squats (atg) and single leg work such as step ups.
Getting soft tissue work and glute-activation work has also helped tremendously, and my therapist told me that my bad knees were probably partly caused from bad mobility in ankle and hip, plus a weak posterior chain.
So for the last 6 months I have been doing these “off” exercises.
Eg. a 225 lb front squat is really a big thing for me, but a bit of humble pie never hurt anybody (yeah right!!)
Still I?d recommend front sq, rd and single leg work.