If your wrists hurt in the front squat, this is most likely due to improper front rack positioning. If this is the case, you need to first address this by improving front rack mobility and then improving front rack performance via light front squats. If your pain comes from general stiffness, that is one thing. If your pain is more than stiffness and slight discomfort, then opt to perform the front rack mobility drills and improve technique, while using other variations like the hack squat to attack muscular development. (Also, always see a doctor if you’re facing severe pain.)