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Cartilage is 65 to 80 percent water. (Source: National Institute of Arthritis and Musculoskeletal and Skin Diseases)

back and forth over one another. It also absorbs shock from the impact of physical movement. In osteoarthritis, layers of cartilage wear away making the cushioning thinner and less effective. If osteoarthritis becomes serious enough, bone will meet bone, causing decreased movement and pain. Osteoarthritis is usually the worst in joints that bear the most weight, specifically the knees, hips, and lower back. Osteoarthritis is primarily linked with aging, and all of us experience it to some degree (whether or not it becomes serious enough to cause pain). Older people naturally develop the condition after decades of bodily wear and tear, but overweight and obese individuals typically experience its debil- itating effects at much younger ages. That makes sense when you think about it. Your musculoskeletal system (your bones, muscles, and connective tissues like ligaments and tendons) is designed to carry a healthy amount of weight over the course of your lifetime. With normal usage, this system should serve you well and be relatively trouble free for at least six decades. If you tax joints with a greater load than they are meant to bear, however, those joints wear out sooner than they otherwise would. You could compare this to the brake pads on a car. When you step on your car’s brake, the brake pads press against the spin- ning tires, causing friction that slows the wheels. If enough pressure is applied, the car’s movement eventually stops. This friction is hard on the brake pads, and they wear away a little with each use. Nevertheless, brake pads are built to withstand a certain amount of pressure and friction, and if

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