It’s helpful to view the launch as a system in motion. If the system is configured correctly from the beginning, it will work as expected, as long as there are no glitches along the way. A lot of people don’t realize how critical the discus throw input really is. If your system is not configured correctly, you have virtually zero chance of success. Once the pitcher has a good understanding of the complete technique, he should spend time perfecting his tackle every day.
Setting
A good drive-in begins with the setup at the back of the circle. Feet should be a little more than shoulder width apart at the back of the ring. If the circle is divided in two, the feet must be on both sides of the bisection line.
The toes should be spread and the legs should be bent so that the knees are over the toes. It is crucial to establish this knee angle before the entry of the throw and strive to maintain it until the throw of the discus. The back should be straight with a slight bend at the waist, as if the athlete is preparing to jump. Your chest should be up with your head held high so that it is in line with your spine.
End up
The rope sets the system in motion. This is where the throw begins, so it is critical that the athlete understand the purpose and importance of the rope. Newton’s first law states that “an object at rest tends to remain at rest until acted on by an external force.” After the initial launch setup, it is the string that provides the force that makes the puck/system move.
As the puck is rolled back, it’s important to remember the rhythm of the throw. There should be a rhythm from slow to fast, so the string should be the slowest part of the throw. It is important for the right-handed caster to keep the right foot firmly planted or anchored throughout the string movement. This will allow for a more controlled and balanced string, while positioning the caster to drift to the left as the puck advances. Both arms should be kept long and perpendicular to the body, and be 180 degrees apart from each other.
Disc recoil is based on thrower preference and flexibility, but it should be understood that the more the disc is recoiled, the more kinetic energy is added to the system. The disc should not move back more than 180 degrees. The head/eyes must remain fixed at 0 degrees during the rope.
On entry to the throw, the puck is rolled back and locked in place, the arms are 180 degrees apart, the head and chest are up, and the eyes and chin remain in line with the sternum. The right-handed shooter will shift his weight from the right side to the left side, while pushing the left heel toward the rim. The left foot and knee should rotate 90 degrees. The right foot should remain flat with the knee pushing out from the left.
The axis of rotation for this system should be from the ball of the left foot to the left shoulder. Remember, the left knee should push down on the left toe. The left arm should remain relaxed and extended, without breaking the plane of the left knee. At 90 degrees, the pitcher will work to drive the left knee down, while the right foot stays flat and the knees move away from each other.
When the legs have reached their maximum stretch reflex, the right will appear. The pitcher holds the ball of the foot up with the leg straight and the knees apart as if riding a horse. Remember that the left foot is still at 90 degrees with the knee pushing down. The shooter now aggressively kicks the right heel out to 90 degrees while pushing toward the center of the circle with the outside of the left foot.
The long right leg acts like a lever that moves on an axis, so that when you kick and the left leg pushes, the net result is that the launch system ends up in the middle of the circle in the desired position. The entry and sweep action add most of the force to the launch. At this point, the stage has been set as to how the release will proceed.