Many people accept sore knees as an unavoidable part of getting older.
But knee osteoarthritis is more complicated than simple wear and tear, and several factors that influence the condition can be changed.
Osteoarthritis is the most common form of arthritis. It can affect the hands, hips and other joints, but the knee is one of the places where it causes problems most often.
Inside the knee, cartilage provides a smooth surface over the ends of the bones. It helps the joint move comfortably and helps spread the forces created when a person stands, walks or climbs stairs.
With osteoarthritis, the whole joint can gradually change. Cartilage becomes damaged, the bone underneath can change, and inflammation and other changes around the joint may contribute to pain and stiffness.
Symptoms vary greatly from person to person. Some people have changes visible on an X-ray but relatively little pain, while others struggle with walking, stairs, sleep or everyday activities.
Dr. Abby Cheng, an orthopedic surgeon and rehabilitation specialist at Washington University School of Medicine in St. Louis, says knee osteoarthritis can affect much more than mobility. Persistent pain can influence mood, fall risk, activity levels and quality of life.
The effects can spread into work and family life as well. Someone who cannot comfortably stand, walk or lift may miss work or have difficulty doing a job that requires physical activity.
A reduction in exercise can create additional health problems. Physical activity helps control weight, blood pressure and blood sugar and is linked with a lower risk of several major chronic diseases.
More than 30 million American adults have osteoarthritis in at least one joint. Although risk increases with age, a substantial number of people with the condition are still of working age.
Age is only one part of the picture. A previous knee injury can increase the chance of developing osteoarthritis years later, and the condition is also more common in women and in people with a family history.
Weak muscles around the legs are another important factor. Strong thigh and hip muscles help control movement and support the knee during everyday activities.
Excess body weight can add further stress. Every step places forces through the knee that are greater than a person’s body weight, so losing even a relatively small amount of weight can reduce the load on the joint.
Cheng gives a useful example. For a person who is overweight, losing 10 pounds, or about 4.5 kilograms, can reduce the stress on the knees by about 40 pounds, or 18 kilograms, during each step.
This does not mean people with knee pain should immediately begin a difficult exercise program. Activity can be increased gradually, and a doctor or physical therapist can help someone choose exercises that match their ability and symptoms.
Strength training is often particularly useful. Exercises that build the thigh muscles can improve stability and make common movements easier without requiring intense workouts.
Walking, cycling, swimming and other forms of movement may also help people remain active. Contrary to a common belief, recreational running itself is not necessarily a cause of osteoarthritis and can be part of a healthy lifestyle for many people.
Diet is another area people can work on. A pattern based largely on vegetables, fruits, whole grains and other minimally processed foods can support a healthy weight and overall health.
Cheng also recommends cutting back on highly processed and sugary foods. Although diet alone cannot rebuild damaged knee cartilage, healthier eating may help with weight control and may reduce processes in the body linked with inflammation.
For people who already have osteoarthritis, treatment can include several approaches. Knee braces, anti-inflammatory medicines, injections, strengthening exercises and rehabilitation can all be considered depending on symptoms and medical history.
Knee replacement surgery is usually reserved for severe disease when pain and loss of function remain serious despite other treatments. Modern surgery can greatly improve life for appropriately selected patients, but not everyone with arthritis will need an operation.
One misconception is that a family history of arthritis makes prevention pointless. Genes can influence risk, but they do not control everything that happens to the joint.
Maintaining muscle strength, avoiding unnecessary weight gain, staying physically active and protecting the knees from serious injury may all help. These habits also provide benefits for the heart, brain, bones and metabolism.
The guidance comes from Washington University School of Medicine in St. Louis. It emphasizes that knee osteoarthritis deserves attention because its effects can extend well beyond the joint itself.
The advice is practical, but it is important to keep expectations realistic. Lifestyle changes can lower risk and improve symptoms, yet they cannot guarantee that osteoarthritis will never develop or eliminate established joint damage.
Overall, the most useful message is that knee health is not simply a matter of luck or age. People cannot change every risk factor, but keeping the body active, maintaining strength and managing weight can give the knees a better chance of functioning well for years.
Source: Washington University School of Medicine in St. Louis.
