“No, these are not tattoos (纹身),” he said, “they are for pain in my joints.”

I am still searching for the Root of Tattooing, the Root of this ancient Tradition of inking someone’s Skin – in all Tribes it is said to have healing benefits, although those benefits vary across the World…
an interesting Article of a Traveller in China that came across therapeutical Tattoos;

http://www.vagabondjourney.com/therapeutic-tattoos-in-china-an-ancient-tradition-in-modern-times/