What's best for arthritis: elliptical or treadmill?

Dr. Keith Roach M.D.

DEAR DR. ROACH: If I have the beginnings of arthritis of the knee, is an elliptical machine better to use than a treadmill? -- M.D.

      ANSWER: If you had an inflammatory arthritis like rheumatoid arthritis, there are powerful medicines that can dramatically slow or stop progression of the disease. So I'm going to assume you have osteoarthritis, which is by far the most common arthritis of the knee. 

       No treatment is known to stop the progression of osteoarthritis. But exercise is one of the most effective treatments to reduce pain and especially to increase function. This is counterintuitive to many people ---- even many doctors are loath to prescribe exercise because for years osteoarthritis was considered a "wear and tear" injury of the joint. Research shows this not to be the case. Although joint injury can lead to development of osteoarthritis, regular exercise does not. Many studies have shown that a graded exercise program (starting slow and easy, and gradually building up) can lead to better function and endurance.

       Unfortunately, many people with severe osteoarthritis have such pain that exercise seems impossible. People write to me that they just can't do any exercise, and indeed, it can get to the point where any movement is so painful that joint replacement becomes the only viable option. But for people with early arthritis, like you, and even moderate arthritis, exercise is a powerful tool. 

       Elliptical machines put less impact pressure on the joint and will be better tolerated by people with more-advanced arthritis. Pools provide the most support for your joints. However, you can do whatever exercise feels best to you. Both treadmills and elliptical machines are an investment (so is a gym membership, once the pandemic is under control), but brisk walking is cheap and effective.

       DEAR DR. ROACH: In regard to your recent column on COVID-19 exposure, though it may seem logical to advise the person to avoid playing tennis that night with a contact of a COVID case, the person who was the contact was described as having "not seen his son for at least one week before the diagnosis." In fact, the recommended look-back time for defining "contact" is 48 hours before the onset of symptoms or before a positive sample was collected in someone who is asymptomatic. According to the Centers for Disease Control and Prevention, a "close contact" is "someone who was within 6 feet of an infected person for a cumulative total of 15 minutes or more over a 24-hour period starting from 2 days before illness onset (or, for asymptomatic patients, 2 days prior to test specimen collection) until the time the patient is isolated."

       Stating that the father of the son needs to quarantine would lead to many more people quarantining than is currently recommended. Though that might truly be useful, current efforts are aimed at contacts of known cases whose exposure was within the period when the risk of transmission was most significant. -- M.K.

      ANSWER: I appreciate Dr. M.K., who is a professor of medicine and an infectious disease specialist, for writing. I wrote my answer to be as cautious as possible, but Dr. M.K.'s point is correct that the last exposure to the son was several days before the son developed symptoms -- and presumably several days before the son had the positive COVID test, though the submitted question implied the test was earlier than the symptoms. The father would not currently be recommended to quarantine by the CDC's guidelines. However, a person should consider their own risk of severe complications should they become infected when planning activities.