Walking and Standing Good posture is the first step to preventing most kinds of back pain. Good posture maintains the back's three natural curves that give it a slight "S" shape. For good posture, your spine, muscles, and joints must work together. Strong, flexible muscles in the abdomen, hip, and legs support the natural curves of your spine. Joints in the hip, knee, and ankle provide balance and allow you to maintain good posture in any position. Body mechanics is the term for the way you position your body when you walk, sit, stand, bend, lift, or lie down. Understanding body mechanics helps you maintain good posture and manage or prevent back injuries. Body mechanics starts with good posture. When standing or walking, keep your spine straight, with shoulders back and directly under your ears. Tuck in your chin. Tighten the muscles in your abdomen and buttocks. Keep your knees slightly bent, not locked. Wear comfortable, low-heeled shoes that provide good arch support. When standing for long periods, put one foot on a stool, step, or box, and switch legs often.