Not to re-hash some good info posted already; some tips on squatting:
1) you can't squat in pain ! pain is inhibitory to muscle contractions. you will develop compensatory movement patterns and initiate other orthopedic problems - get to the doctor & maybe a PT (if either say just don't squat or that squatting is dangerous, leave immediately! they are idiots!)
2) Leg extensions increase knee shear - do not do them if you have knee pain/problems. For most people they are a useless injury proving open chain exericse. If your life/job dosen't require open chain knee extension DO NOT DO THEM!
3) leg presses & leg extensions CAN NEVER EVER replace squats!! Squats are a primal movement pattern that we must do daily! I.E. sitting in a chair, at a desk, driving a car and taking a shit alll require full, 3 dimensonal squatting !!! Does someone help you on or off the toilet?? If you completely eliminate squats they will eventually have to!
4) squat flat footed, no plates or blocks! - it increases load on the knees and changes the path of the bar.
5) you must break parrallel when squatting, stoppng at 90 degrees leaves you open to masive knee injury for no muscles are supporting your knees, just the ligaments - that's why the orthopedist has you sit on a table and bend your knee and pulls on the tibia (Lachtman's test) to see the integrity of the ligaments.
6) squatting above 90 degrees over develops the quads in relation to the hams & glutes, thus creating muscle imbalance and further problems - also people look like assholes when they load up the bar and barely move it while screaming their head off!
7) GO BACK & READ #1!!!!
Good luck & keep squatting!!
S
