I;'m probably not the best person to post on this, as I'm not an expert and my books are too far away (they're actually less than 30m away but I'm just lazy) but here goes.

The salmon leap is referenced in some of the Irish myths as being one of a number (12?) of tasks and feats that all true Irish warriors must be capable of performing. A lot of them seem to be more displays of strength, coordination, agility, endurance and courage than actually being useful combat techniques. Whether or not the "Salmon Leap" looks like it does in that video is anyone's guess, but my guess is no.

In addition, the actual jump used there would be utterly useless against massed ranks. Roll over man 1, right onto man 2's gladius/spear/axe/spiky-thing-on-the-top-of-his-helmet.

Finally, some of the Roman writers reference Gauls and Britons performing some pretty amazing tricks and techniques in combat. Caesar mentions that some warriors would catch pilum from the air while running at the Roman line and throwing them back. And I can't remember if it is Caesar or Tacitus but I think one of them mentions warriors leaping over the first rank of legionairres, crashing into the second and causing general mayhem 1/2 a second before the rest of the warriors start partying. Of course, they did die after performing their little jump...

Finally, I recall reading that Galatians, at least once, rolled underneath the spears of a Pergameme (?) phalanx and coming up stabbing in the front rank. The Greeks got round that one by having the front rank kneel down next time. Mind you, after rolling all that way underneath a line of sarissas, I think I'd be too dizzy to do anything except lie down and close my eyes. I can't remember where that came from so I wouldn't put too much faith in it.

If any of this is wrong, someone who knows better can correct me. If any of this is right, I think I'll have a celebratory drink :)

Hodgson