Optimal Javelin Flight: Physics and Fixes

Like many events in track & field, the javelin throw is an interesting combination of basic physics and human ability. It can be fairly easy to calculate the correct way to throw, but it can be much harder to execute. Correcting technique can also be hard if you are not sure what you are doing wrong. Here you will find common javelin flight problems and possible fixes.

Optimal Javelin Flight

In order to have the perfect throw we first need to know what the perfect throw consists of. Many factors go into how far a javelin will fly, but for the sake of keeping things simple we will cover 4 of the basics:

Release Height

Throw a javelin. Now throw a javelin off the top of a 30 story building with the same amount of force. What happens? The javelin from the building is going to cover more distance- basic physics. Obviously there is not this much difference in competition, but the moral of the story is the higher the release, the better.

Javelin Speed

Essentially the faster you can get a javelin moving at release, the farther it will go (with a perfect release). This is probably the most important factor in your javelin throw success. A ratio that is fairly accurate to figure out speed/distance is as follows:

For every 1m/s increase in release speed, the javelin flight gains 4m in distance. Or for my American friends- for every 2.2mph in release speed, the javelin flight gains ~13ft in distance.

Release Angle

The second most important factor in the throw is the release angle. For most objects the optimal flight angle is 45 degrees. Do to the javelin’s aerodynamics and speed its release angle should be around 36-40 degrees. This is calculated from the path of the javelin’s center of gravity.

For every 3 degrees in difference there is roughly a 2m difference in distance (with perfect attack angle).

Attack Angle

The above factors are also affected by the attack angle of the javelin. This is the amount of rotation the javelin is off the center of gravity’s flight path in any direction. The optimal attack angle is very close to the center of gravity to slightly above it, creating an attack angle between 0-5 degrees. This is usually the angle that determines the flight of the javelin, which brings me to problem flights and their fixes.

Problem Flights

First understand the following:

The attack angle rotation can be divided into 4 hemispheres: upper, lower, left, and right.

Dive Left (for right hand thrower)

Common cause: Attack angle is rotated into the “left hemisphere” so to speak. Usually this is caused by the athlete over-rotating the trunk during the block. As a result the throwing arm is pulled across the body. This is called “bailing” in jav terms. Bailing also robs the throwing arm of speed creating a shorter throw.

Fix: Have the athlete focus on bringing their left fist to their left armpit and stopping during the block.

Dive Right (for right hand thrower)

Common cause: Attack angle is rotated into the “right hemisphere”. This usually happens when the javelin gets away from the head. This can also be an indicator of a lack of flexibility in the throwing arm, causing the arm to travel away from the body instead of along the center path of the javelin.

Fix: Have the athlete focus on keeping the javelin next to or touching the head as long as possible. Start with easier throws and build up. Make sure to do plenty of arm flexibility drills before throwing.

Nose Dive

Common cause: Attack angle is rotated into the “lower (and usually the left) hemisphere”. This is a fairly rare problem, but if your athlete does have it check where you are looking. Many times dropping the nose is caused by athletes who are looking down or their block leg has too much give to it. Doing this leads the chest to collapse, causing the “reverse C” to collapse. It can also be caused by bailing.

Fix: You want your chest to stick out and up. Remain tall during the throw and your block leg as straight as possible. Luckily your chest tends to follow your head, so keep your chin high and the body should follow.

Dropped Tail

Common cause: Attack angle is rotated into the “upper hemisphere”. Dropping the tail is probably one of the most common problems with a javelin’s flight. This is usually caused by the athlete trying to muscle the throw, or releasing a moment too late. Sometimes the drop can be caused by the block leg slightly collapsing, pulling the whole body down, and as a result the end of the throw.

Fix: The athlete should remain relaxed and fast during the throw. The block leg should be as straight as possible. I have found a quick meditation and visualization session to be the best medicine to help when I have this issue.

Note:

Remember, these are just generalities. It can be hard to actually tell what a thrower is doing wrong without seeing them in action.