By Mike Maynard
Mike Maynard was the head track & field coach at Boise State from 2000 to 2009 and at UCLA from 2009 to 2017. This piece is adapted from the January 2010 issue of Long and Strong, Glenn Thompson, Editor.
The discus throw allows for a wide range of individual expression of the technical fundamentals. Current success- ful technical expressions of the discus cover a wide variety of styles and philosophies of throwing. The physical parameters of successful discus throwers, on the world stage, indicates the necessity for well above average size. For example, world class male discus throwers tend to be about 1.95m/115kg [6’5”/254lbs]. However, exceptions to these physical parameters readily exist on both the national and world levels. The athletes who comprise these exceptions typically compensate for physical deficits with a particularly exceptional specific physical talent(s), and/or an exceptionally well-adapted technical model.
The dynamic nature of the discus movement has histori- cally witnessed a variety of successful technical expressions. Many of these utilize large and sweeping movements to accomplish mechanical advantage within the throw. Those technical models will continue to be successful. The technical model should seek to maximize the athlete’s particular physical attributes (i.e., system of levers, range of movement, bio-motor capabilities).
The technical model to be presented and discussed in this article is meant to pare down the movements of the discus thrower to a bare and essential minimum.
The objective in restricting the variables of the technical movement within the discus model is meant to create a system of throwing which is efficient and easy to replicate as a model. The efficient technical model promotes consistency of expression via repetition, faster progression toward habituation of movement, and offers the opportu- nity of lower degradation of the quality of movement due to competitive stressors. In addition, this type of model can offer coaches a simple and precise task-oriented teaching progression. The successful lowering of the minimum physical parameters necessary for high level success, offered by an efficient technical model, may also offer coaches a greater population with regard to athlete selection.
ESTABLISHING SYSTEM AXIS
A key and central element of the technical model being presented is a stable and consistent axis of the thrower- implement system. This system axis must be established and maintained throughout the throw. Athlete posture is the basis of this efficient dynamic axis. The development of an efficient axis can be accomplished by stabilizing the trunk axis in an upright posture with the hips tucked under the athlete during the preliminary wrap of the discus. This vertical posture should be maintained throughout the entire throw, with the exception of the axis tilt in the power position.
Coaching Cue: The coach should introduce, and consis- tently cue, the athlete to maintain an erect posture with the hips stabilized and tucked underneath throughout the learning process. Posture precedes balance.
The objective of establishing this axis is intended to minimize head radius of the athlete throughout the entire movement. The error of excessive lateral deviation of axis is best observed when viewing the athlete from the back of the circle and towards the throwing direction, or 180 degrees. The goal is to minimize any lateral deviation (I.E. wobble) of the axis. This stable and efficient axis allows forces imparted to the system, such as the push in the direction of the throw off the single support base out of the back of the circle, to result in a corresponding increase in forces available to be applied to the discus during the delivery phase. If the axis remains efficiently stable, the treatments of the free leg, drive leg, and CMT displace- ment, can be organized to create effective resultant forces for the discus delivery. An efficient system axis allows for effective maintenance and use of separation/torsion, in the form of stored elastic energy, within the throw delivery.
PATHS OF CENTER OF MASS
An additional technical goal of the athlete during the discus throw should be the creation and use of dynamic / directional displacement of the center of mass. An efficient technical model should seek to align those forces gener- ated parallel with the intended direction and angle of projection of the throw. This aim should be achieved while creating a dynamic and specific directional balance of the thrower-implement system about an efficient axis. Direc- tion, paths of the thrower/implement system, and angle of implement projection should be taught early and often within the teaching progression of the discus throw.
Paths to be covered should include the paths of Center of Mass of the Thrower (CMT) and Center of Mass of the Implement (CMI) and with intended angles of projection and orbital consid- erations. Development of the awareness of these paths by novices, early in the learning progression, can be effective in the development of spatial and kinesthetic awareness of the athlete. At the outset of the discus movement, the transition from double support to single support necessi- tates a shift of the CMT toward the single support base.
The degree of this shift over the base of support is relative to the degree of Center of Mass displacement / counter in the direction of the throw (i.e., hip counter). In order to create an effective throwing direction the necessary path of the CMT is roughly as follows (see Figure 1).
ALIGNMENT OF FORCES
The actions of the swing/free leg and the push-off of the drive/support leg aid in establishing the intended path of projection of the implement. The CMT and the forces established by the swing/free leg and drive/support leg out of the back of the circle combine to create a resultant which is ideally parallel to the discus projection path.
Those forces should be directed as closely as possible to align with both the intended angle of projection, as well as the directional path of the implement. The direction of the push out of the back of the circle should be aligned with the path of the CMT (see Figure 1). The push direction may require modification, due to the actions of the free/ swing leg, so that the resultant system direction is accurate to the intended path. Reduction of deflected forces makes it easier to apply those forces generated during the throw into an efficient delivery sequence. This efficiency of movement offers either higher performance for a given level of forces generated or equal performances with less force required, relative to a less efficient model of throwing.
The discus orbit is a resultant of the system axis and the forces applied to the thrower/implement system. The push-off of the first single support establishes the direction of CMT, as well as the pitch angle of the orbital plane. When viewing the throwing movement from 90° to the side in the throwing direction, the angle of the push-off of the single support leg should be applied parallel to the desired angle of projection of the implement (see Figure 2).
Coaching Cue: Single-support push angle alignment can be determined by checking to see that the angle of the lower leg (tibia) is parallel to the angle of projection of delivery, when the athlete executes the push out of the back of the circle (see Figure 3).
The discus orbit should be symmetrical. A symmetrical orbit is evident when the implement is neutral, relative to horizontal, at both 90 and 270 degrees. There should be minimum yaw of the orbit on the longitudinal axis. Apply- ing forces within a symmetrical orbit aids the efficiency of the thrower-implement system upon delivery.
Coaching Cue: Orbital mistakes, such as late high point or “scooping,” should be addressed by developing proper axis, and proper alignment of forces with regard to both direction of CMT and angle of projection.
SEPARATION AND TORSION
Separation and torsion are distinct skills that are required in the discus throw. The elastic energy that the combined movements of torsion and separation provide serves as the primary engine for the acceleration of the discus in the delivery. A technical model that stresses the maintenance of an efficient axis offers the athlete the ability to maintain and utilize separation and torsion to a higher degree.
Coaching Cue: Torsion can be defined as the positive angle, or space, created between the hip axis, and the trailing end of the shoulder axis. Separation can be defined as the positive angle or separation of axis between the shoulder axis and the throwing arm axis as it extends through the CM of the implement. For the purposes of this article, and to better delineate between the aspects of these energy storage systems, the terms total lead/space will be used to define the cumulative amount of torsion and separation (see Figure 3).
SEPARATION & TORSION
In the case of each of the skills of separation, and torsion, the thrower can pre-stretch the agonists, and thereby facilitate and maximize the storage of elastic energy. In addition to creating the ability to exploit the stretch reflex, the throwing side arm/ lever, and trunk, range of motion is maximized through these movements. Proper delivery timing will generate the conditions optimal for the efficient summation of forces and delivery sequence.
SEPARATION
When properly executed, both separation and torsion offer the thrower an opportunity to maximize bio-motor and mechanical components of the throw. Separation can be achieved if the athlete contracts the triceps, and cocks back the throwing side shoulder. The contraction of the rear throwing side (antagonistic) musculature causes a relaxing of the chest deltoid area (agonistic) musculature that increases both the range of motion of the throwing arm lever, and the storage of elastic energy.
Coaching Cue: The coach should introduce, and consis- tently cue, the athlete/ thrower early in the learning process to actively contract the antagonistic to the throwing side musculature. Active cues such as “squeeze the backside muscle,” or “cock & lock’’ the rear shoulder and inside head of the triceps aids in maximizing separa- tion. Lowering the throwing side arm increases range of motion and contributes to proper discus tilt on delivery.
Over time and as throwers progress in the skill of creating and maintaining separation, it is likely that passive cueing of the skill of separation can be used. This is especially true for those throwers who have gained stabilization of the skill. The passive cueing of separation would be achieved by instructing the thrower to relax and leave the discus trailing behind the system during the movement as far as possible. The goal of this passive cueing is meant to maximize the total lead in the system.
National and world-class discus throwers can at times lose their separation levels during high-intensity throws. The most common cause of this fault is related to an inefficient axis. The problem can also be the result of an especially effective push-off of the single support/drive leg out of the back of the circle. The stretch created by an effective push creates stretch through the chest and may cause the discus to “bounce” forward, thus creating slack in the system. While the creation of this negative separation is not a goal of the technique, the cause can be a positive sign of the effective translation of force to the thrower- implement system. The skill of regaining position and the necessary separation level with the corresponding elastic energy can be taught through effective use of drills.
Coaching Cue: The Cast & Catch style of the South African drill can be effective for this purpose. This drill can be practiced with balls, puds, pipes, or just about anything that would typically be thrown in training. It may be advisable to use the standard style of South African drill, with a constant total lead, when throwing the discus as the primary drill. This will reduce confusion within the athlete regarding the differing goals between the drills.
The lack of separation of the throwing arm axis relative to the shoulder axis can be simply described as “slack” in the system. Slack becomes evident to the coach by observing the relationship between the throwing arm axis relative to the shoulder axis. A negative separation angle is easily noted as the discus seems to lead the thrower as the thrower-implement system moves in the direction of the throw toward the orbital high point. The negative/neutral separation angle effectively inhibits the opportunity for the thrower to impart any force to the implement until the slack is removed from the system. If the separation angle is reduced to any extent during the conclusion of the first single support or non-support phase it should be regained prior to the re-contact of the second single support in the center of the ring.
TORSION
Torsion can be defined as the positive angle, or space, created between the hip axis, and the shoulder axis (see Fig. 4). Torsion affords an opportunity to store elastic energy in the torso of the thrower for use during the delivery sequence. The counter wrapping of the free arm in non-support can be an effective means of re-establishing and maintaining torsion. Actions of the free side arm and shoulder, when combined with active counter-rotation and contraction of the torso musculature, will maximize the torsion level between the shoulder axis and the hip axis. It is possible to establish a torsion position upon the preliminary wrap of the discus movement by “setting” the left shoulder inside the left hip in the initial wrapping movement of the throw. Some athletes are sensitive to the tendency of this early torsion to somewhat inhibit rotation within the throw. However if the axis is efficient, then additional rotational forces can be added via the swing/ free leg inversion, as well as shortening the free arm, to counteract this inhibited rotation. An early establishment of torsion greatly reduces the opportunity for later mistakes that may result in the loss of torsion.
Coaching Cue: The torsion position can be set from the back of the circle by setting the shoulder axis behind and inside the leading side hip axis. Cue the athlete to hold this left shoulder inside the leading side hip until delivery sequence is initiated. Free arm can aid in re-establishing torsion in non-support by casting it in a subtle counter- wrap motion.
SECOND SINGLE SUPPORT
The second single support contact phase is a critical phase within the throw, because it represents a major opportunity for the loss of angular velocity of the implement due to thrower-implement system friction. This friction tends to reduce the separation/torsion level via system decelera- tion. The loss of separation can be avoided if there is an active cueing of squeezing the throwing side arm/shoulder back to maintain separation level. This can be achieved by cueing the contraction of the antagonistic/backside musculature, and/or an active inversion, or pivoting ahead, of the second single support side both prior to and subsequent to the second double support re-contact (i.e., left foot re-contact for a right-handed thrower).
The loss of angular velocity of the thrower-implement system, due to the second single support friction, can also be mitigated by reducing the time between the second single support contact and the second double support contact. Delaying the re-contact of the second single support in the center of the ring will reduce friction, and shorten the time interval between the second single support contact, and the second double support contact (i.e., the time between right foot, and left foot touch-down for a right-handed thrower). This delaying of the re-contact of the second single support foot can be accomplished by lifting the knee of the swing / free leg (right leg for a right- handed thrower) during the nonsupport phase following the swing invert action. The re-contact of the second single support can also be delayed by the active dorsiflex- ion of the swing leg foot. These movements serve to delay the re-contact and shorten the time interval between single support and double support. They also have the added benefit of creating knee flexion and an ankle lock position which aids in the storage of additional elastic energy in the leg for use later in the delivery sequence. The re-contact of the second single support should be with the foot axis oriented at, or around, 315 degrees. However, a case could be made for delaying re-contact even later to reduce the negative impact of friction on implement velocities.
Coaching Cue: The athlete should be instructed to turn in the air, not on the ground. The desired angle of the foot axis upon re-contact of the second single support should be approximately at 315 degrees. It is important that the thrower does not stay on the first single support beyond the line of direction of the CMT out of the back of the circle. This error leads to the technical fault of “over- rotation” and results in a poor heel tuck/ heel recovery on the drive leg.
TILT OF AXIS IN POWER POSITION
When observing the axis of the system, from the perspec- tive of 90 degrees in the throwing direction, there should be a tilt of the axis away from the throwing direction when the athlete is in the Power Position (see Figure 4). However in order to maintain effective summation of the system upon delivery, there should still be minimal deviation of the axis (i.e., head radius) in the system axis. The axis tilt aids in establishing the angle of projection of the implement. The axis tilt maximizes the force path of the implement, and thereby the opportunity to impart forces in the delivery of the discus. In addition the axis tilt delays the transition of the CMT in the direction of the throw, which results in a more effective use of forces generated. The tilt/orientation of the axis is achieved during the non-support phase of the throw. As the free leg is inverted, and lifted, a center axis of rotation is established. The free arm, and shoulder, is counter wrapped away from the direction of the throw. This wrapping of the free arm side maximizes torsion between the hip axis and shoulder axis, and initiates the tilt of the axis away from the throwing direction. The lower body travels toward the front of the circle, and the tilt is com- plete. The tilt of the axis is relative to the desired angle of projection of the implement, and the technical proficiency of the thrower (i.e., throwers with greater technical mastery can achieve and utilize a greater axis tilt).
Coaching Cue: During the learning phase atletes should be instructed to maintain a more erect vertical posture throughout the throw until technical mastery allows the use of greater system axis tilt. Axis tilt should be introduced as the novice thrower becomes more adept at achieving the fundamentals of the standing throw position.
COACHING CONSIDERATIONS
Teaching progressions should be based on task/skill identification and should develop the athlete toward mastery of necessary skills. The coach should seek to create specific learning periods with an objective emphasis towards specific skill acquisition. The process of skill introduction should follow the following process:
Coaching Cue: Repetition of an introduced movement creates a learned movement. Stabilization of a learned skill occurs through repetition of the learned movements. Habituation of a movement skill occurs through repetition of stabilized movements.
- Introduce the skill
- Drill the skill
- Instill the skill (via repetition)
The goal of the teaching progression should be to move motor skills along the continuum from learned movements to habituated skills/ movements. Related/ parallel move- ments and task-oriented drills should be used, in conjunc- tion with cueing within the throw, to aid in the learning progression of identified skills. For the aid of developing an appropriate skill progression the following is a non- exhaustive list of skills related to the discus technique:
Task/Skill Identification
1. Double Support Axis/ Balance/ Posture
2. Hip/ Pelvis stabilization
3. Pivoting in Single and Double Support
4. Transferring/ Countering of CM
5. Single Support Axis/ Balance/ Posture
6. Use of Focal Points
7. Establishing and Maintenance of Torsion & Separation
8. Free Arm Mechanics
9. Swing/ Free Leg Actions
a. Sweeping
b. Inversion
c. Knee Drive/Lift
d. Dorsiflexion (ankle lock)
10. Drive Leg Actions
a. Sprint/ Push
b. Heel Tuck/ Recovery
c. Adduction
11. Maintenance of position Axis/Balance/ Posture during Non-Support Rotation
12. Re-contact Stabilization
a. Single Support
b. Double Support
13. Effective Transfer of CM
14. Use of Torsion & Separation in Delivery Sequence
15. Blocking Mechanics
a. Upper body
b. Lower body
16. Recovery Mechanics
SUMMARY
It is possible to pare down the movements of the discus throw to an essential minimum. The creation of a throwing model based on a stable vertical axis is an important part of that endeavor. Such a model may promote consistency of expression, faster progression toward habituation of movement, and lower degradation of quality of movement due to stressors. A stable system axis allows for maintenance of increased levels of torsion and separation, as well
as promoting the effective use of the elastic energy stored in the torso. In addition a stable system axis will aid in maximizing the utilization of properly aligned forces for the delivery sequence.
