Many Pilates reformer exercises are done lying down with the head on the headrest. The important thing to be aware of is that the headrest can be down flat or propped up. In many cases, it will be your preference whether the headrest is up or down. You will want to find out what is most comfortable for your neck. However, it is important to have the headrest down anytime you are going to bring your legs over your head. There are also exercises where you turn around and put your feet through the headrest area.
The shoulder blocks keep you stable on the reformer as you push or pull the carriage. Often your shoulders are against the blocks, but there are also exercises that use the shoulder blocks as props for the feet, knees or hands.
