Make sure they know what to do if they start experiencing those symptoms. Supervisors need training too. Whoever is in charge of any part of the program needs training on their responsibilities. Every three years, take a close look at your program. This is one standard that may, in the long run, actually save you money.
Back injuries are among the most expensive ones to treat.
If your ergonomics program can prevent just one of those, it will have proven its worth. The Battle for a Safe Workplace.