I have a B&R bar and have marks on my back where the bar sits. I've been squatting for over a year, and this never was a problem until the past week or two. Could this mean that the bar is slipping down slightly when I'm squatting? Also I've noticed that my spine of the scapula feels like the bar is sitting directly on top of it. I feel like I'm positioning the bar correctly at the top of the deltoids. I know that that bone goes slightly downward diagonally. Therefore, while I feel that I have the bar correctly positioned right below the spine of the scapula, the bar still hits as it goes across my back where the bone angles down.