If you are in a chair and can shift your own weight, do so at least every 15 minutes or have someone reposition you at least every hour. Reduce friction by being sure you are lifted rather than dragged during repositioning. Bed sheets or lifters can be used. Use pillows or wedges to keep knees or ankles from touching each other. Place pillows from mid-calf to ankle to keep heels off the bed.
Products are available such as water mattresses or gel pads to help reduce pressure.
Eat a balanced diet. Eat foods high in protein and calories. Drink plenty of fluids. If you cannot tolerate a balanced diet, ask your doctor about nutritional supplements. DO NOT sit on a rubber ring.