People who have osteoarthritis in their knees can delay the course of their disease by moving more. This is suggested in an epidemiological study that researchers at Boston University published in Arthritis Care & Research. The idea that exercise causes the cartilage in joints to wear down in people with arthritis, and that they should therefore should not do anything to put pressure on their joints, is not entirely correct.
OsteoarthritisOsteoarthritis is one of the most common diseases that affect the joints. The cartilage gradually wears down in the joints as the result of a process in which pain in and inflammation of the affected joints increasingly hampers their daily functioning.
Doctors used to regard osteoarthritis as a disease of aging about which little could be done, but more recent research has shown that people who develop arthritis are genetically predisposed to this.
StudyThe researchers gathered a group of 1788 men and women aged between 50 and 79 al of whom had a higher risk of developing osteoarthritis in the knee joint. They were not only heading towards old age, but many of them were also overweight or were already experiencing knee problems.
1003 of the participants already had knee problems that were visible on scans [Radiographic knee osteoarthritis]. Of this group 390 participants already actually had symptoms [Symptomatic radiographic knee osteoarthritis].
The researchers followed the subjects for two years, and recorded how the arthritis developed in their knees. The researchers also recorded the amount of light to moderately intense exercise that the participants did: they all wore a pedometer that counted the number of steps they walked each day. 1000 steps = 760 m = 12 minutes [for people not engaged in sports].
ResultsThe more serious a person's knee osteoarthritis is, the less quickly they can walk. The more the participants walked, the less likely that their walking speed would decrease.
Rheumatologists use WOMAC-scores to express the extent to which people's functioning decreases as a result of arthritis. Exercise reduced the likelihood of a less favourable WOMAC-score.
As far as the researchers could see, 7500 steps or about 6 km of walking a day provides the knee joint with optimal protection. This figure was for the total amount of walking in a day: so it included walking up and downstairs at home, doing shopping and walking the dog.
The figure below shows that every 1000 steps taken daily reduced the participants’ chance of decline by 16-18 percent.
ConclusionIn a press release Daniel White, the first author of the study, advises people who have an increased risk of developing osteoarthritis to walk at least 3000 steps a day, and if possible to gradually increase this amount to 6000 steps. [sciencedaily.com June 12, 2014]