I haven't been able to click onto the link as I have some weird security setting on my computer that doesn't let me go onto some links. However from the comments that follow particularly about the West African link, I think I can guess what is being talked about.
I lived in The Gambia when I had DS1 and it is considered best practice to massage your baby very, very vigorously and stretch out their limbs by holding them by one leg etc. My SIL did this to my DC1 at least once a week - as I cannot get onto the link, I have no idea if it is the same thing exactly, but the massage did look very rough but I don't remember DC1 crying at all whilst it was being done.
Babies who do not have this massage done to them are considered to look stiff and be uncomfortable. It is considered very, very beneficial to babies and women who can do this (it's a learned skill, not everyone can do it) are well respected.
I know how bad it must look to Western eyes and I have no idea if the massage actually helped DS1 or not. I don't think it hurt him either. To be fair, he wasn't newborn when this was done - more like from 3 months onwards...
Just saying...