I have a Manfrotto 460MG 3D tripod head which I like very much. However since starting to use a Mamiya C3 I found it rather difficult to turn the knobs sufficiently to stop the camera from slowly tilting - on one occasion it wasn't very slow and crushed my finger.
After spending far too long looking at new tripod heads I thought I'd try a little modification - replacing two of the knobs with levers.
I can report that the levers are indeed very effective and at £8 the pair off eBay a very economic solution.
I offer this in the hope that it might be useful to anyone else with incipient arthritis or an unnecessarily heavy camera.
Yeah man, that's a way to go. C3 isn't heavy so much as the weight is way above the mount, so it's really nice to be able to clamp it easily. Wide base cameras in general make it weird getting to some knobs, too.
I don't like knobs on tripods. My arthritis isn't bad, but it's still a lot easier to feel and have leverage that way. Especially in the cold, like a sunrise or night work.
The typical disadvantage of levers is that they stay unwantded positions, necessitating shimming. These "modern" levers enable to easily adjust their direction any time.