When you have rheumatoid arthritis, the handle of your knife is as important as a well-sharpened blade. I don't own the knives that Annette is describing on her blog. However, I do have a number of knives with handles that are of different thicknesses.
My favourite knives are made by OXO - under the Good Grips label. The soft, cushioned rubber handle fits comfortably in my hand and, because it's made of rubber, it provides a better gripping surface than many other knives.
As we slice through time, these knives have had a good workout. So good, that I've had to replace two of them.
Unfortunately, there has been a change in the design. Compare the handles of the older and newer models in the picture, below. Apparently, the newer knife on the right has been on a diet.
Dependent upon your needs, and how your hands are, see if you can hold the knife - if it's not mummified in packaging - and mime slicing and dicing to see how it fits and feels.