Shoes provide comfort, support, and protection, while taking pressure off important tendons and ligaments. But not just any sneaker or slipper will do. If you can bend yours completely in half, it’s time to invest in a better pair, says Dr. Nicole Brouyette, a senior staff podiatric surgeon at Henry Ford Health in Detroit. Same verdict if you flip your shoes upside down and find that the soles are so worn out, they’re uneven.