Scissors jump

Once the take-off leg has left the ground (but not before) the athlete should attempt to pull the upper body face down towards the knee, also to keep the centre of mass as close as possible to the bar.

The arms can be brought back to the sides during clearance, as a further measure to keep the centre of mass as close as possible to the bar.

Even with these measures, it is clear that the bar remains considerably below the centre of mass, so the scissors is far from an optimal clearance technique.

Until the invention of the eastern cut-off by Michael Sweeney in the 1890s, high jumpers used fairly primitive variants of the basic scissors style.

This gives a very efficient clearance, but it made for an uncomfortable landing in the early days, when the jumper typically fell into a sandpit.

The first successful exponent of the modified scissors was Clinton Larson of Brigham University, in Provo, Utah, who was US champion in 1917.

Larson is credited with an exhibition jump of 6 ft 8 inches (2.03m), which exceeded the world record of the time, held by western roller Edward Beeson.

When the rule was repealed, in the late 1930s, the main result was the development of "dive" variants of the western roll and straddle techniques.

For a good example, see the video of Stefan Holm nonchalantly scissoring over 2.10m while still wearing his track suit,[5] or Mutaz Barshim over 2.16m at training.