Rheumatoid arthritis is a local inflammation closely linked to diet, which can be the consequence of a diet too rich in carbohydrates, seed oil, and anti-nutrients contained in plants. Not everyone is equal when it comes to anti-nutrients, which explains why some people experience symptoms more easily than others.
I cured my rheumatoid arthritis by adopting a ketogenic diet. It's a type of diet whose benefits are too often ignored by medical doctors, even though thousands of studies have been published on the subject for over a century. Fortunately, many doctors are talking about it on YouTube and elsewhere, and are themselves practicing this diet for their own well-being.
There are also truly ergonomic keyboards and keyboard layouts, designed to avoid pain. Such keyboards are developed and sold by Dygma, Kinesis, MoErgo, X-Bows, and ZSA, to name but a few (in alphabetical order). If you use keyboards intensively, you should consider buying one. They're expensive, but well worth it. And they're fully programmable.
As far as keyboard layouts are concerned, there is an interesting resource to consult:
A comprehensive guide to alternative keyboard layouts (Dvorak, Colemak, Gallium, etc.), how to learn them, and tips for programming and Vim.
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