The people in the pictures seem to be doing something different than figure 8.
Also, have a look at the cited sources, small print at the bottom right. However, I don't think it is a pleasure to be cited in such a context.
Maybe a case of "modern journalism": Present the first thing you stumble upon on the web?
As no other sources than the doctor and the director of the technical science centre are cited I assume that the figures about distance and speed also come from this page. However, the numbers seem rather low to me (greater than 15 m/s = 54 km/h as speed and average distances of 78 m for men and 53 m for women). It would be nice to know how the writer determined these very exact numbers for average distance.
It really saddens me to read that someone was killed by a sling
.
Several other seem to have suffered from concussion caused by stones slung presumably from slings. Otherwise two broken jaws and other facial injuries are mentioned.
Rockman: Is there a difference in meaning between the expressions "huaraca" and "honda" (de lana)?