Front squats require a lot more shoulder and wrist flexibility, that's for sure. You're sticking your elbows straight out and resting the bar on your front deltoids. The bar should be sitting next to the base of your neck, resting on your deltoids. You should not have to expend any effort to keep it in place. The advantage of this movement is that it prevents you front learning forward when pushing the weight upwards, putting all the effort onto your glutes and quads instead of your back.