Given the nature of work/sea states for/in which RIBs are used, it is highly likely that crew will be subject to some form of heightened ergonomic and anatomical risk.
In a work situation in Europe, employees' rights in this area would be addressed under the Physical Agents (Vibration) Directive. Here's an link which details some points raised during the consultation stages of this Directive - some good RIB-specific points made by The Chamber of Shipping, Bureau Veritas and Human Sciences & Engineering Ltd.
IMHO, people with pre-existing, or a predisposition to, musculoskeletal problems (bony/muscular/joint conditions) probably shouldn't be engaging in regular RIBbing lifestyles.
The best the rest of us can do to stay ache-free is to carry out some simple neck & shoulder stretches before setting off (sounds naff, but actually works) and to maintain a wide base of support with knees bent whilst standing.