Usually the issues with hard drives come from the heads. If the head is parked and the drive is not spinning, it can handle a bit of abuse before breaking. If the drive is plugged in and spinning then it becomes fairly fragile, even though most drives know to park the head in case of a fall. Also, in any case it's always better to have a backup of your data, just in case.

I don’t know a ton about hard drive failures, but you could run a SMART check on it to read diagnostic data. It’ll give you a state of health, both impact related and general wear and tear. If that’s clean and the drive read/writes fine, in my experience its fine. As the other comment mentioned they’re far more durable when powered off than running. If travel is a concern, the external hard drive enclosures are generally just a 2.5” HDD with a Sata -> USB adapter. If it’s able to be disassembled, you can replace the hard drive with a solid state drive like this and gain more speed and durability.

if the drive was gonna fail from a drop, you'd no immediately they're pretty robust when the heads are parked, if the disk was spinning and the heads were flying that would be a different story

if you test the drive and it read writes fine it'll be good, just be careful next time