Any vibration have possibility of causing damage to your harddisk... do a ScanDisk to check on your drive for error. If error detected, backup all your important data before the worst happening.

You wouldn't know if the internal is damaged or not. I did drop once from the height of 1.5 metres from the ground and it is still working flawlessly without any error after ScanDisk. However, my unfortunate friend straight away need to send his unit back to factory when dropped at the same height. Still able to work and access doesn't mean the internal didn't receive any damage as well. Best if you can do a throughout disk diagnostic by downloading the utility from the HDD's manufacturer website.