I have just been told I have a RSI in my wrist. What can I do long-term to make sure this doesn't happen again

This depends to an extent on the type of movement that caused the injury. If it was a hobby that you do regularly and that involves repeated wrist movements then you may need to consider wrist supports or different techniques. You could consult a sports therapist who would be able to advise you on these matters.

If the injury is the result of your working conditions then there are many tactics that can be used to help reduce the risk for the future. Talk to your Human Resources department at work, as they should be able to assess the risk and implement strategies such as changing the equipment you use or giving you better seating or a different desk arrangement.

You can also take glucosamine sulphate (1,500mg daily) to support your musculoskeletal system, and use Devil’s Claw at the first sign of any discomfort. Taking magnesium regularly may also be helpful, as it is excellent for relaxing muscles.

Best wishes

Earle