Two distinct discus throw release styles that have sparked debate for many years. Fixed foot throwing where both feet remain on the ground and a jump release where both feet are off the ground.
Is there a version that is better? This debate is an important one as biomechanical studies have shown that between 62 to 73% of the final release velocity is achieved in this phase of the throw.
Its impossible to say which style of delivery is most effective as many athletes have been successful using both styles. Jurgen Schult set current mens discus world record in 1986 with a jump delivery but reverted to a fixed foot style of throwing later in his career. Although he never threw as far again he did become a very consistent major games competitor throwing with fixed feet.
There is a tendency amongst women to throw fixed feet. The pattern in men is more variable but the majority of world class men release with a jump release.
Women likely remain fixed feet as they can have as much as 60 to 70% of a world class males strength levels while only handling an implement that is 50% of the weight. The trend in womens discus throwing is to make maximum use of range in the power position to throw long and therefore a fixed foot action suits this purpose.
Developing a Fixed Foot Release
The fixing of both feet to the ground in delivery has mechanical advantages. It allows for a long unwinding from the power position against a braced left side with the axis of rotation running through the left shoulder. This occurs in top level throwers allowing the athlete to create maximal radius in delivery.
To have efficient transmission of the rotational force generated from the hip and right leg the left leg must act in a bracing manner. In order to transfer energy maximally and to allow the hip to pivot it is critical that the athlete have a straight left leg as this provides the rigid lever for these two requirements
Therefore in coaching this technique it is important that athletes have a fully extended braced left leg as a technical requirement. In addition the coach must also ensure that the athlete is conditioned to tolerate the higher and higher braking forces that will be transmitted into the left leg as the athlete throws further.
The Jump Release Thrower
This is very different for the jump release thrower. Here the emphasis is on the vertical component of the athletes delivery. It could be said that unlike the fixed foot thrower the discus thrower who jump releases lifts and then rotates.
Although the radius of the discus delivery is smaller the increase in angular velocity is greater and this then becomes the release velocity when it leaves the throwers hand. So this delivery style can achieve exactly the same velocity as a fixed foot delivery even through the radius of the discus path is less.
An Individual Approach
Whichever style an athlete uses or a coach suggests is really down to the make up of that individual. The fixed foot thrower tends to be more tall and rangy. Coaches with athletes who do throw fixed feet should consider flexibility specific to trunk and shoulder rotation to be an important part of training.
They should also be very vigilant to make sure that the rotational muscles of the trunk, the obliques, are very strong along with the upper chest and shoulders to deal with the force applied through them for a long period of time during delivery.
For the jump release athlete can sometimes be shorter as this methods also affords the athlete a greater height of release.
These athletes as they emphasise a strong vertical component in their delivery tend not to be as concerned with range in the power position although they must still be conditioned rotationally their major focus must be on very strong but also explosive leg musculature.
Therefore reactive training such as plyometrics may play a greater role in the development of an athlete in this style of throwing than one that is fixed foot.
Ultimately there is no one style that fits all athletes. Discus coaches and discus throwers together need to decide which style suits them best and apply the technical and conditioning suggestions presented to improve their discus technique and ultimately their distance.