Here is a pic of a Spanish Resurrection from about 1430 or so. The guard on the viewer's left has a couple of those javelins that we see sometimes, but mostly don't pay enough attention to. The image can be found here

Cropping out the guy in question shows that he has (red!) finger loops on his javelins.

Zooming in further, shows how they are bound to the shafts with cord.

Tod does a video on these here, and a follow up video herer
I must thank Tom B. for turning my on to this photo-stream.
Mac