You may have not known this, but Physiotherapy has existed for so many years now that people might have been practicing it for so long and that it was still not labeled as Physiotherapy.
Since in the beginning, us people are not lazy to start with. Prehistoric Humans, Cavemen, or whatever we may be calling them always travels, hunt on different places, and sleeps on rough ground which certainly will cause body pains if you do that all the time. Ancient civilization like Egyptians and Romans always work hard to expand their glory, fight other nation, and spread their culture just to be known. We on the other hand, the modern age, also do lots of things such as waking up early morning and go to our jobs just to earn money, have nightlife’s, and perform variety of activities.