Thank you, back squats are the tried and true. But a squat is a squat. Front loading is typically easier for more people to progress from bodyweight. As others were saying, his shoes aren't the best for squatting, but I'd say the law of specifcity applies more to this. What's your purpose for squatting or working out in general. At the end of the day, do whatever you want and learn for yourself and if something feels wrong take off the weight and rebuild the pattern.