The Fosbury Flop

The arc position and the center of mass

Once in the air and on his back, the athlete must adopt the iconic arch or bridge position.

The biomechanics of the Fosbury Flop are fascinating because it allows the athlete's center of mass to pass under or through the bar, while his or her body segments pass over it one at a time.

This is mechanically more efficient than the older styles (scissors or ventral roll) where the center of mass had to rise above the bar.

To achieve the arch, the athlete must relax the shoulders and drop the head back (facing the bottom of the mat), while pushing the hips up.

The head guides the movement; if the athlete sticks the chin to the chest to "look at the bar", the arch is broken and the butt knocks down the bar.

The stepping sequence: Shoulders, Hips, Feet

The stride is a precise time sequence. First the head and shoulders pass. At that point, the hips are low.

As the shoulders come down the other side, the hips peak over the bar. Finally, as the hips begin to lower, the legs should come up.

The "sitting on the bar" error occurs when the athlete flexes the hips before the hips have cleared the obstacle.

The coach must work on the timing of this reverse undulation, ensuring that the athlete is not in a hurry to land. Patience in the air is key to allowing physics to do its job.

The final snap or recovery

The final phase of the franking is the "Snap" or recovery whip. Once the hips have released the bar, the danger lies in the heels or calves bringing it down as they fall.

To avoid this, the athlete must perform a reflex action: bring the chin to the chest vigorously and extend the knees (kick) upward.

This mechanical action triggers a chain reaction that lifts the feet rapidly away from the bar.

It is an explosive movement that occu