Turkana foot knives?

[LJ]

I've seen a few mentions of these on the web as being Turkana foot knives. But the style of decoration doesn't look particularly Turkana to me. In fact I'd be happier accepting an origin of Southeast Asia, or even Birmingham.

And ... foot knives? Why not worn on the hand as knuckledusters, or tools for scraping the white stuff out of coconuts, or scraping bark off rubber trees ?

Does anybody know of any evidence linking them to East Africa, and being used as weapons worn on the feet?