What is barra vasca?

Barra vasca is a prohibited javelin throw style originating in Spain.

In 1956, Spain wanted to break the Scandinavian dominance in Olympic javelin. The Spanish found a loophole in the rules, and Felix Erausquin, a national level hammer thrower, came up with an idea to throw the javelin as if it was hammer or discus. He developed a new technique on basis of an old Basque style of spear throwing.

Erausquin grabbed the javelin with overhand grip, laid the butt of the javelin upon his back, span a couple of revolutions as if he was throwing discus - and slung the javelin. The style was revolutionary - and immensely effective. The Spanish athletes got the javelin to fly close to 100 metre mark. They were confident they'd win the javelin in Melbourne Olympics 1956.

Turned out the style was immensely dangerous - to other athletes, officials and spectators. Only some 10% of the throws landed in the sector, and some trajectories had landed in the grandstand. IAAF prohibited this style almost immediately, and the javelin was thrown in Melbourne 1956 with normal style.