Pre-Existing Conditions and Workers Compensation
Any kind of insurance is a double-edged sword, and it often feels like each party is on the wrong side of the deal. Those who have insurance feel like they can't get a break when they need help, and those providing the insurance often feel like everyone has their hand out for everything under the sun. Add into this that there are a select subset of the population taking up most of the available healthcare resources and the insurance fraud that occurs on a regular basis, and you can see why it can make the case of pre-existing conditions even trickier. We'll look at what you need to know in the case of workers comp.
The Straight Facts
Obviously, you do not want to preclude a perfectly capable employee just because they have typical problems like a heart condition or knee problems. However, there have been cases where this has been known to cause disputes. Employees may blame something related to their condition by something that happened at work, and while you aren't required to pay out for this, the burden of proof will now be put upon you to come up with evidence that their working was not responsible and that their pre-existing condition was. You are only held responsible if their condition worsens due to being on the job. For example, if someone has a back condition and there is no reasonable accommodation to get them ergonomic equipment, then you may be found at fault.
What You Can Do
Documentation is highly encouraged for all employees, but be extra careful for those with pre-existing conditions. Have employees sign off on forms that acknowledge the steps you've taken to reduce the likelihood that they will be injured on the job. Also, try not to take any chances. If you have someone with a knee injury who really shouldn't be lifting heavy objects, then don't ask them to fill in if that's not within their job description. Too often the needs of the moment outweigh the needs of the future. If you make too many risky moves though, then chances are you're going to land yourself in some type of hot water. Especially considering that back pain is extraordinarily common, it's a pre-existing condition that simply can't be taken lightly.
Additional Considerations
Each state has their own specifications regarding pre-existing conditions. For example, if the original injury was not from on the job, then insurance may deny the claim. The same goes if it can be proven that a worker operated outside their doctors orders. Any type of lie made by the employee is the best way to build a case that their claim is fraudulent.