INTRODUCTION ON DISCUSS THROW

The ancient Greeks have described this event better than any other. They used stone and then

bronze disks between two and six kilograms in weight and 21cm to 34cm in diameter. The

discus first appeared in the Ancient Games in 708 BC. In 1896 the discus was included in the

revived Olympic Games in Athens. Throws were made from a pedestal that measured 60cm

by 70cm. At the same time, the Swedes were throwing the discus from a 2.5m square.

In 1897, in the USA, the event took place in a seven foot diameter circle, increased to

2.50m in 1908. The discus itself was standardised in 1907 at 2kg in weight and 22cm in

diameter.From the original static throw of 1900, styles evolved through the Nordic swinging

throw to the current style, introduced by Clarence Houser (USA) in 1926, of turning and

skipping before release. Both hands contests, where aggregates were recorded, were

organised until the 1920s, when single hand contests became the norm.

In 1954 the concrete throwing circle was introduced, greatly increasing the possible

speed of rotation.The first recorded women's results, with a discus weighing 1.25kg, date

back to 1914 (USA) with contests also held around the world using 1.5kg implements. A

standard 1kg discus was adopted for the Olympic Games in 1928 while the IAAF ratified its

first official world record in 1936. The discus, the object to be thrown, is a

heavy lenticular disc with a weight of 2 kilograms (4.4 lb) and diameter of

.219 m (0 ft 812 in) for the men's event, and a weight of 1 kilogram (2.2 lb) and diameter of

.180 m (0 ft 7 in) for the women's program.

(3.3 lb) discus, the Junior men (1819 years) throw the unique 1.75 kilograms (3.9 lb) discus,

and the girls/women of those ages throw the 1 kg discus. In international competition, men

throw the 2 kg discus through age 49. The 1.5 kilograms (3.3 lb) discus is thrown by ages 50

59, and men age 60 and beyond throw the 1 kilogram (2.2 lb) discus. Women throw the 1

kilogram (2.2 lb) discus through age 74. Starting with age 75, women throw the .75

kilograms (1.7 lb) discus.

The typical discus has sides made of plastic, wood, fiberglass, carbon fiber or metal

with a metal rim and a metal core to attain the weight. The rim must be smooth, with no

roughness or finger holds. A discus with more weight in the rim produces greater angular

momentum for any given spin rate, and thus more stability, although it is more difficult to

throw. However, a higher rim weight, if thrown correctly, can lead to a farther throw. a solid

rubber discus is sometimes used.

To make a throw, the competitor starts in a circle of 2.5 m (8 ft 214 in) diameter,

which is recessed in a concrete pad by 20 mm. The thrower typically takes an initial stance

facing away from the direction of the throw. He then spins counter-clockwise (for right-

handers) around one and a half times through the circle to build momentum, then releases his

throw. The discus must land within a 34.92-degree sector. The rules of competition for discus

are virtually identical to those of shot put, except that the circle is larger, a stop board is not

used and there are no form rules concerning how the discus is to be thrown.
 The distance from the front edge of the circle to where the discus has landed is

measured, and distances are rounded down to the nearest centimetre. The competitor's best

throw from the allocated number of throws, typically three to six, is recorded, and the

competitor who legally throws the discus the farthest is declared the winner. Ties are broken

by determining which thrower has the longer second-best throw.

The basic motion is a forehanded sidearm movement. The discus is spun off the index

finger or the middle finger of the throwing hand. In flight the disc spins clockwise when

viewed from above for a right-handed thrower, and counter-clockwise for a lefty. As well as

achieving maximum momentum in the discus on throwing, the discus' distance is also

determined by the trajectory the thrower imparts, as well as the aerodynamic behavior of the

discus. Generally, throws into a moderate headwind achieve the maximum distance. Also, a

faster-spinning discus imparts greater gyroscopic stability. The technique of discus throwing

is quite difficult to master and needs lots of experience to get right, thus most top throwers

are 30 years old or more.

There are six keys movements of the discus throw: wind up, move in rhythm, balance,

right leg engine, orbit, and delivery. The wind up is one of the most important aspects of the

throw because it sets the tone for the entire throw. The wind up is both mental and technical.

It is mental because the wind up sets the thrower up for the rest of the throw.
Figure 1 : Phases of the discus throw

The following are the technical aspects: flat right foot, on the ball of your left foot,

keep your weight evenly distributed between your feet, and not being overly active, which

results in the waste of energy. Although the wind up sets the tone for the entire throw, the

rhythm of the throw is the most important aspect. It is necessary to move in rhythm

throughout the entire throw.

The best throwers contain the same amount of time in each phase while completing a

great throw. Focusing on rhythm can bring about the consistency to get in the right positions

that many throwers lack. Executing a sound discus throw with solid technique requires

perfect balance. This is due to the throw being a linear movement combined with a one and a

half rotation and an implement at the end of one arm. Thus, a good discus thrower needs to

maintain balance within the circle.

during the throw until the end, where the thrower must extend their shoulders upward to get

good lift under the discus. If extension is executed properly the discus will be at the right

angle to ride on the air current and thus be taken a farther distance.

PURPOSE

The purposes of the present study were a) to describe the kinematics of discus throw

movement, and b) to determine those kinematic variables that were most closely related to

large impact forces in discus throw.

SIGNIFICANCE OF STUDY

The need for the present study focused around three main issues. Firstly, determining the

kinematic factors that are contribute to a forceful movement discus throw is fundamental to

the improvement of the techniques of discus throw. Secondly, there has been very little

scientific research conducted on the movement of discus throw. Finally, knowing which

factors are important in developing an effective discus throw enables practitioners and

instructors to focus their training on developing these components.

1. To estimate what are the factors that affect the movement of the right leg engine, , between

professional athlete discus thrower with upsi athlete?

2. To estimate the time velocity factors that affect the speed of movement starts from flat

right foot until the release of the discus from the fingers.

3. To estimate the length of discuss throws stance.

4. To estimate the correct foot placing in discuss throws.

RESEARCH QUESTIONS

1. Is there any factor that affects the movement of the right leg engine, between professional

athlete discus thrower with upsi athlete?

2. Is there any time factors that affect the speed velocity from starts of the turn flat right foot

until the release of the discus from the fingers, between professional athlete discus

throwers with upsi athlete?

3. Is there any significant differences in length of discuss throws stance, between

professional athlete discus throwers with upsi athlete?

4. Is there any significant differences on correct foot placing in discuss throws, between

professional athlete discus throwers with upsi athlete?

The following limitations are also acknowledged:

1. Only the movement of discus throws of each subject selected as their best was analysed.

2. Subjects were given 15 minutes to complete a warm-up that they deemed to physically and

mentally prepare them to perform an optimum discus throw.

3. There was no control over whether or not the perceived maximal effort by subjects

corresponded with the greatest impact force that they were capable of.

4. It was considered that factors such as the day of the week, time of day, and the performer's

physical condition did not affect subjects' performance.

DEVELOPMENT OF A DETERMINISTIC MODEL

Although this study is primarily of a quantitative nature, it will include a technique from

qualitative analysis: deterministic modelling. Hay & Reid (1982) outline the four steps of a

qualitative analysis as follows:

1. Development of a deterministic model showing relationships between the result and factors

which produce that result.

2. Observation of the performance and identification of faults.

3. Evaluation of the relative performance of these faults.

4. Instruction of the performer based on the conclusions.

Only step one, development of a deterministic model, will be discussed here. A

deterministic model divides a skill or movement into the mechanical factors that completely

determine the outcome or result of that skill. Each factor can be independently identified, and

the interrelationships between factors in the model become clear. The contribution of a given

factor can be assessed partly by its position in the model, but validation by scientific

investigation is 10. necessary to be certain.

Consequently, an important application of deterministic modelling is its use in

identifying all of mechanical factors important in the success or outcome of a specific skill

without unnecessary duplication. It follows that those factors identified are, where possible,

what an investigator should measure. Deterministic models have a result at the apex that can
be either objective or subjective, depending on how it is measured. The result is the goal or

outcome of the skill or activity that is modelled. Examples of objective measures are the

distance a javelin is thrown, the weight lifted, or the height jumped. Subjective measures are

used for situations where a score is awarded by judges, or advantage is gained from a pass.

Where necessary, the next step in developing a qualitative model is the division of the result.

This step is only applicable where the result can be seen to consist of distinct parts.

The final step is to break the result (or divisions of the result) down into factors that

completely determine it. These factors in turn can also be divided down into determining

factors until further division is redundant, or all the factors of interest have been included.

When the model is being developed, it is imperative that the following conditions are

fulfilled: a) each factor at each level is a mechanical quantity, and b) when a factor is divided

into sub-factors, it must be completely determined by these sub-factors. Such a model is

referred to by Watkins (1987a) as a mechanical approach, as opposed to a sequential

approach, to qualitative analysis.

In a later article on quantitative movement analysis, Watkins (1987b) suggests that the

two objectives of such study are to a) evaluate the end result of a movement, and b) examine

and/or evaluate the sequence of movements or movement pattern responsible for the end

result. It is important to note that a given result can have many different models, depending

on the subsequent analysis approach used; the model that is best for a situation depends on

the type of analysis that will follow.

characteristics of technique in throwing the discus. A theoretical model of mechanical factors

of the athlete's technique that completely determined the distance of the throw was developed

in order to identify the measurement variables.

Name Asman Coktang

Height 175

Weight 80

Age 23

State Kunak, Sabah

Experiance in 6 years
Discus Throw
Competition Won Silver medal in state level Athletic Championship (2009,2010,2011)

Types of Thrower Full Swing Thrower

Name

Height

Weight

Age

State

Experiance in
Discus Throw
Competition Won

Types of Thrower Full Swing Thrower