Weather forecasting knee - does it exist?
Some people with arthritis claim that they can forecast the weather with their knees. Is it true?
The relation between pain and weather has been extensively studied, especially in people with arthritis. While a number of studies have shown that it is a real effect that high humidity coupled with low air pressure is indeed associated with pain or stiffness in joints, a truly objective relation between weather and arthritis severity has yet to be established.
For instance, arthritis patients do not report dramatic increases in symptom when bathing or swimming. Also, patients easily tolerate swings in air pressure when flying near a storm.
If so, what causes the pain?
Because there is still no conclusion on the relation between weather and arthritis severity, the jury is still out as to whatcauses the pain. Several explanations have been given. Here are just a couple of them. Take them with a grain of salt.
One explanation is that weather changes make injured ligaments swell, and the nerves around the joint sense this as pain. Another is that air within the joint expands as the air pressure falls, again causing the nerves to report pain.
- 'The last word', New Scientist, website at www.newscientist.com
- 'Ask the experts', Scientific American, September 2006