THE PHYSICS OF HIGH JUMP

The high jump is one of the most popular sports that has been in existence since the beginning of the Olympics in 1896. In the early days, everyone jumped in a way that was acceptable so far they are able to get over the bar successfully. Over the years, there have been various techniques used during the high jump contest by various athletes. There are two (2) categories of high jump;

• Standing jump
• Running jump

Standing jump: High jump first started as a standing jump. This was where the athlete stands and jumps through the bar using mostly the “scissors technique”. This category of jump was last seen in 1912.

Running jump: This is where the Athlete runs towards the bar to make a jump either using the “scissors” , “straddle” or “Fosbury flop” techniques.

Throughout the years there have been various techniques that have been used by various athletes to clear the high jump heights. Every athlete has which of the techniques was best suitable for him/her.

There are various techniques of high jump over the years and they are:

• Scissors
• Straddle
• Western Roll
• Fosbury Flop

SCISSORS: This is where the jumper approaches the bar so as to take off from the outer foot.

The scissors jump

STRADDLE: The jumper crosses the bar face down with his legs straddling it. Unlike the scissors jump, the jumper takes off from the inner foot.

The straddle jump

WESTERN ROLL: This is somewhat like the straddle technique but here the jumper’s side or back faces the bar.

The western roll technique

FOSBURY FLOP: This was the starting point of the “EVOLUTION OF HIGH JUMP”. This technique is a popular high jump technique that is still used even until today and it was established by “DICK FOSBURY” during the Olympics in Mexico 1968 with a jump of 2:24m.

The Fosbury technique

Dick Fosbury tried to jump in a different way seeing as he couldn’t use the other high jump techniques to win. Instead of the straddle method( face towards the bar), he jumped with (back towards the bar — “FOSBURY FLOP”).

THE PHYSICS BEHIND THE FOSBURY FLOP

CENTER OF MASS

The center of mass of an object is about finding the object’s “BALANCE POINT”. We can easily locate the mass of every object by locating the average position of all of its mass, by taking account of how the mass is being spread around the object.

For Example, The center of mass of different shapes can be seen at the point of intersections.

Center of mass of various shapes

The center of mass of an object is about finding the object’s “BALANCE POINT”.

The center of mass for humans moves all the time as we go through our daily activities based on various postures determines the position of the center of mass.

For Example;

• When we “stand” the center of mass is around the stomach.
• When we “lift” our hands in the air the center of mass moves upwards from the stomach.
• When we “bend” the center of mass moves below our bent stomach.

A pictorial example of different postures of man and the center of mass

FOSBURY FLOP TECHNIQUE

• During this technique, the jumper runs fast so he will be able to divert his horizontal velocity to vertical velocity and take a jump. The jumper can either run from the right or left-hand side of the runway and take off on one foot.

• The secret behind the Fosbury technique is when one jumps using the Fosbury flop, the center of mass/gravity is below the bar.

• The jumper can apply the same level of force with the straddle technique but the difference is the jumper can raise his body much higher than before. I.e. the jumper’s arching body can go higher even when the bar goes up.
• Fosbury said, “ if they get that arch, it is a mechanical advantage to use that technique”. Fosbury modernized the straddle technique with the Fosbury flop.
• The Fosbury flop brought about a new technique by splitting the jumper’s body away from the center of mass, giving it more room to clear higher and higher heights/bars.

• Jumper arches his back approximately 140 degrees. Take off velocity X mass = change in momentum.

BREAKDOWN ANALYSIS BEFORE TAKING A JUMP

• ENVISIONING( FORESEEING)
• Envision your approach before getting to the bar.
• Envision your take-off after you have gotten to the bar.
• Envision your landing: Ability to be able to foresee that you have jumped over the bar even before you take the jump.
• Most athletes count their steps around the curve before getting to the take-off point so they don’t miss a step and can’t get the best jump. Mostly 4 or 5 steps.
• It is advisable to mark the start of your curve, it gives you and heads up before taking off.
• Every high jumper knows the rules of the game.

High jump is a very technical and calculative event and it doesn’t seem as easy as just jumping over the bar, it takes a lot of brainwork. It took just one man to change the history of the high jump and its techniques completely which all athletes are still making use of even till now. As much as the Fosbury flop is now the most used high jump technique, it doesn’t mean it is compulsory to jump using the Fosbury technique. The rule of the High jump is to jump higher with whichever technique you choose, just ensure you get over the bar without any external rules broken but I doubt if there will be another way of jumping if it is not “THE FOSBURY FLOP”.