You just need to ensure you're forcing your hips back so the tension goes onto the hamstrings. You also need to ensure your legs are straight enough that the bar doesn't hit the knees on the way down. The bar also has to stay over your feet to keep the weight in your COG, if you move the bar even a small amount away from your COG then you'll load up the wrong places.
You can see these cues in my video. I'll be pushing them a little further this week to get more horizontal.
You can see these cues in my video. I'll be pushing them a little further this week to get more horizontal.