I suspect the Athenian business is silly. Our information about the building and operation of the triremes is quite sketchy, or was within the last ten to fifteen years.
As I recall the Tutsis had a step up before the bar, from which they jumped. What the mechanical advantage of that might be, I don't know.
I'm tired of this nonsense, probably because I'm a modern wimp--australopithecus surely had a higher tolerance for pseudo-scientific nonsense.
Does this mean that people were jumping 2.52 in the early 1900s?! If so, did they use the Fosbury Flop and it faded out after that? Because if not, they probably jumped that height with the Scissors-Jump, which seems highly unlikely...