From what I've seen (I'm no medical professional), the most typical issues come from the basic issue of doing just about anything repetitive and static for a long duration with not enough breaks. Several of these issues are probably common to any form of long computer use:
- Wrist issues - from typing in an improper position, and from any limitations imposed by the particular laptop.
- Neck/shoulder issues - from the monitor not being aligned well with the human using it.
- Eye strain - staring at lit surfaces for hours on end are just not what humans evolved for.
- Leg/hip issues - from sitting, sometimes in bad chairs, for hours on end.
- Just not moving around enough - I don't care if you sit in a rejuvenating yoga pose for 8 hours - being static for really long periods of time is not a good plan for humans.
The trick with ergonomics is that it's not one size fits all. Humans are built in all sorts of variations. So are laptops, chairs, keyboards, monitors, and desks. Also, any previous physical issue, or lack of good posture while working can be exacerbated by prolonged strain of any sort.
IMO - medicine and just about anything relating to physical health is an art, not a science, and if you really want comprehensive advice - always see a doctor... but a sanity-building checklist with no consideration of budget might include:
Hire true ergonomic experts - there are businesses that consult on this, and who will work with each individual in your office to figure out the right conditions for them. A tall person is different from a shorter person, a person with eye strain is different with a person with tennis elbow, a person who works on the laptop in between meetings is different from a person who sits on the laptop all day while simultaneously on conference calls.
Invest in the right equipment for the right person - don't self-diagnose, and don't necessarily buy the same super-awesome high end whatever for everyone - this is where expert advice really helps.
Figure out a policy for repeating as necessary - people change, technology changes, usage changes - figure out how often you'll be inviting the experts back - don't make it a one-time thing.
Also get advice in overall conditions that affect the group - lighting, air quality, temperature - things you all have to share.
Create a culture of holistic health - taking breaks, making sure sure small pains are addressed before they are big issues, avoid a culture of complaining and suffering in favor of a culture of "if something is wrong, let's fix it".
Determine any off-site, out of office policies - are you willing to provide ergonomic support out of office? At home? At other sites? No one's budget is infinite, so where do you draw the line?
Figure out at what point you will require offical medial notice. Ergonomics is generally taken to mean setting up an office environment that prevents injury. So if a pre-existing employee health condition adds to the cost of ergnomic measures, is that a disability that requires medical verifiation? Figure out a policy so you don't end up enforcing the rules randomly.
There's really is never a "perfect" case. Every office I've worked in has tried to at least attempt some humane working conditions, but there's always a point where something for someone is too expensive without a serious justification. And there's a balancing act of universal purchases to save money and administration effort vs. getting the right thing for the right person.
A good office culture will solve much of that - giving people enough flex to swap and trade to get the right balance will usually do it. For example - having some variety of keyboards, trays, mice, monitors, headsets, etc - and finding a way to balance it out.