“Front Squat: Although most guys can use slightly more weight on the back squat than on the front squat, traditional back squats involve far more activity in the hamstrings and glutes. The front squat targets the quad muscles since your back is straighter during the movement and allows you to pile on the pounds to blast your legs.”
The Labs Final Word: Although the front squat IS amazing for the quads it is impractical exercise for most trainees in order to stimulate the quads enough for growth and development. It is true that the typical movement is more quad dominant than ‘normal back squats,’ however the majority of trainees can NOT perform the front squat adequately enough to tax the quads as much as a well performed back squat. Limitations in wrist, shoulder, upper back, hips, and ankles prevent a full range of motion on the movement limiting the ability to fully tax the quads. Therefore, when most people break down on this movement it is not from quad fatigue, but support and stabilizer muscle groups that either hold the barbell in the rack position or simply help the lifter remain upright with the erectors and upper back. The ultimate problem being everything else fails before the quads can truly be worked adequately.
While technically the front squat is a better movement for direct quad stimulation, practicality gets in the way. Be sure to master a good full range back squat first and see how the quads respond. Likewise, there is nothing wrong with getting the glute and hamstring work with the back squats for better overall leg development. Finally it should be noted that high bar Olympic style back squats should be chosen over the low bar power style, sumo style, or their various counterparts.