New habits, such as sleeping on your side, along with decreased space for breathing (as your baby grows, there’s less room in your chest for you to breathe deeply and expand your lungs) can lead to tension in your upper body. Stretching your thoracic spine (the upper part of your back) and shoulders can ease your discomfort.
Thoracic spine stretch
Place your hands on the back of a chair, palms facing up. Slowly walk your feet back until your arms and legs are straight. Back your hips up until your torso is fully extended and your hips are behind your feet to create the correct angles [shown]. Take deep breaths so that you feel the sides of your rib cage expanding.