Report it to your employer right away, even if the injury seems minor at the time.

Reporting deadlines vary enormously by state, from as little as a few days to as long as several months, and missing yours can jeopardize your claim entirely. Some states simply require you to report as soon as practical. Since you are unlikely to know your state’s deadline off the top of your head, the safe move is to report immediately.

Then: get the injury documented in writing, ask for your claim number, seek medical attention, and keep your own record of what happened, when, and who you told. If symptoms appear a few days later, which is common with back and shoulder injuries, report that too rather than waiting to see whether it settles.