You might consider looking at each job, breaking it down by actual tasks - keyboard work, writing by hand, talking on the phone, using books or binders, stapling, meetings, reading, and so on. Try to get a sense of what portion of the workday is spent doing each task and then look for ways to spread them out more evenly, particularly tasks which involve repetitive motion. You want to be careful of over-specializing jobs. In fact, it's become a feature of modern work that jobs are getting more specialized, and that's exactly part of the problem. By doing some cross-training you not only spare people unnecessary injury but the group in general becomes more flexible.
People enjoy their jobs more when there's variety.
Be certain, of course, that you're not rotating people between two equally repetitive tasks. Often a worker is afraid to even stop and close their eyes or take a deep breath for fear they will be seen as unproductive. Micro-breaks truly are a very important element of any prevention strategy. Workers must know that they're welcome to practice this habit, that it's sanctioned by management. At the least, they are a way of delaying the fatigue point.