Stress on arthritic knees significantly eased by small weight loss

A new study says that overweight people suffering from arthritis in the knees, could diminish the stress the knees take with every step, by just losing one pound.

In a study, of 142 overweight adults with arthritis in the knees, the researchers found that for each pound participants managed to shed, there was a 4-pound reduction in the force hitting their knees with every stride they took while walking.

According to the researchers, that means that dropping just one pound would reduce the "load" on the knee joint enough to translate into slower arthritis progression.

Apparently excess weight can contribute to the both the development and progression of knee osteoarthritis, which is one of the most common forms of arthritis.

Osteoarthritis occurs when the cartilage cushioning the joints breaks down over a period of time, causing inflammation, pain and stiffness.

Experts usually recommend that overweight and obese adults with knee arthritis lose weight and exercise to help manage the condition, almost as a common sense measure, but whether weight loss actually slowed the progression of knee arthritis was unclear.

Dr. Stephen P. Messier of Wake Forest University in North Carolina, and colleagues in their study, tried to gauge the effects weight loss can have on arthritis patients' knee mechanics.

The participants were all older adults with disabling arthritis symptoms, and were part of a larger weight-loss study.

At the beginning of the study, and 6 and 18 months later, the researchers performed a "gait analysis" of each patient. The team found that for each pound participants lost during that time, there was a four-fold greater reduction in the force going into the knee with each step they took.

The investigators say that measurement when accumulated over thousands of steps per day, meant an enormous reduction which would be 'clinically meaningful'.

One question however they cannot as yet answer, is whether such weight-loss effects hold up over time, and whether they can slow the progression of knee arthritis.

The research is published in the journal Arthritis & Rheumatism, July 2005.