Precautions to ensure the safety of your knees since teenage can go a long way in protecting them from future risks such as arthritis and the need for knee replacement, experts have suggested.

As many as 50 percent of all people develop arthritis in at least one knee by the time they reach 85 years of age. The risk is seen higher among obese people. Extra pounds increase the strain on the knee joints, says Dr. William J. Bryan, an orthopedic surgeon at the Methodist Center for Sports Medicine in Houston.

"Every time you take a step you apply three times your body weight to the knee. When you run it's five times, when you jump it's seven times. If you are experiencing frequent knee pain, lifestyle changes might be in order," Bryan said in a media statement released by the Methodist Center for Sports Medicine.

Dr. Bryan said weight loss is 70 percent diet and 30 percent exercise. "If you think you can eat the same and exercise the pounds away, you are mistaken. You have to change your attitude about the refrigerator for weight loss to happen," he said.

Low-impact activities such as swimming and cycling are better for your knees than high-impact workouts such as running or aerobics. Having good core strength (abs, back and pelvis) also helps protect your knees, Bryan said.

"If you have a strong core, you can better position your foot or knee on the ground to prevent damage. This is true whether you are exercising or performing mundane tasks such as getting out of the car and walking down the stairs," he says.

According to Bryan, knee protection can also be achieved by orthotics. Improper shoes can also lead to abnormal stress. Many patients experience dramatic reductions in knee pain after getting orthotics or shoes specifically made to fit their feet.

"If you have knee pain that has lasted more than two weeks, you need to see a doctor because there might be something mechanically wrong with the knee," he said. "Making a few lifestyle changes might give you a better chance at staving off arthritis and/or eventual knee replacement," he adds.