Techniques Of Javelin Throwing
Observation and analysis is imperative to coaches in order to provide the learner with detailed feedback about their performance (Hay, 1994). Javelin throwing has shown little change in technique throughout the years and elite performers virtually show identical techniques. Some athletes differ with their techniques by rotating the javelin arm forward, down and then extend it back prior to throwing. The most common technique of javelin keeps the javelin stable without any motion then extends it back before forward motion (Carr, 1999). According to Rogers (2000) the javelin is divided into a four phase pattern. These phases are; approach, transition, block and release and follow through.
The approach is the run-up phase prior to withdrawal of the javelin. The run-up develops velocity and this energy created is transferred to the throw. The momentum gathered from the run-up adds 30-40% distance from a javelin that is thrown from a standing position (Rogers, 2000). Athletes prefer to use 12-15 step run up but some find using 8-10 steps comfortable. During the approach there should be a gradual acceleration eventually reaching a maximal, but controllable speed that can be maintained through the transition and release phase. The athlete should be relaxed during the run especially in the upper body and shoulders, maintaining a good posture. The javelin should be carried at a right angle with the shoulder with the javelin kept level and stable whilst in the run-up (Rogers, 2000).
The transition phase is used to withdraw the javelin in preparation for the explosive motion of the release of the javelin. The withdrawal is established with a five-step pattern (for right handed thrower this goes left, right, left, right, left). The withdrawal begins when the left foot lands (after 12-15 step run-up). As the left foot lands shoulders turn 90 degrees to the right and the throwing is extended back with the palm facing upwards, so the arm is level or above the plane of the shoulders. The arm is slightly external rotated at the shoulder joint to ensure the palm is facing upwards. The tip of the javelin should be aligned at the level of the chin with shoulder kept level. During this phase the legs and hips are active. The turning of the shoulder controls hip rotation and feet placement and turning of the hips and feet cause deceleration (Rogers, 2000).
Figure 1. The transition between approach and withdrawal phase with emphasis on the drawback of the javelin.
The final stage of the transition is the most important to gain energy into the release of the javelin, the impulse step. The impulse stride drives the hips and trunk forward. The trunk is kept upright to maintain forwards speed. The right leg is swung infront forward with knee flexed and toe turned up. The left foot then lands forwards as the right contacts the ground (Rogers, 2000).
Figure 2. Final Stage of the transition phase the impulse stride. Emphasis on the high knee drive of the right leg.
The block and release phase is an explosive continuation from the preceding phase. During this phase the hips and trunk are thrust forward against a straight, left leg. The hips rotate with them finishing facing the direction of the throw. As the left leg is planted in a blocked action the right leg drive forces acceleration of the right hip, stretching the trunk. The throwing arm and all the leg action is kept relaxed and trailing. All these actions cause a stretch of the chest and trunk muscles resulting in a flail like action of the throwing arm (Rogers, 2000).
Figure 3. The release phase showing the full extension of the left leg and the right leg driving through the block.
During the follow-through the athlete must think of driving through the block. This forces the body high and onto the left toe after release. Another step should check the forwards momentum to prevent exceeding the foul line (Rogers, 2000).
Analysis of Performance
Using the four phase pattern devised by Rogers (2000) an analysis of a javelin performer comprising of their strengths and weaknesses and comparing them to a good model of practice.
Strengths of the athlete shown come in the approach phase of the javelin throw. The athlete uses a 10-15 step run-up with a gradual acceleration which is controlled by the athlete. A controllable speed enables the athlete to gain momentum going into the transition and release phase where the more explosive movements take place. During the approach phase the athlete also shows a good posture with shoulders and upper body relaxed and javelin kept stable (Rogers, 2000).
During the transition phase of the throw the athlete has good posture and the footwork is exemplary. The athlete keeps the hips high and upper body upright whilst doing the cross-over steps. During the cross-over steps the javelin is stable and is partly extended. The footwork of the athlete is correct and continues the gradual acceleration gained during the approach run.
Prioritising the weaknesses of the athlete are essential so the correct practice drills can be selected and eventually an improvement in technique and performance. The two weaknesses concern the arm positioning and the impulse stride. The athletes arm drops below the plane of the shoulders. This impacts the whip-and flail release as the chest and torso are not kept open (Rogers, 2000; Paish, 2009). During the release phase the block of the left side causes a prestretch of the chest and trunk resulting in a the flail-like action. This cannot occur if the arm drops below the plane of the shoulders. The dropping of the arm below the plane of the shoulders also has biomechanical impacts. The dropping of the arm causes the tip of the javelin to point upwards, causing an over rotation of the javelin.
Fig.4 this image clearly indicates the drop of the shoulder beyond the plane of the shoulder. The image clearly shows the impact this has on the hips, causing them to sink and the points of the javelin, which should be kept stable.
The second weakness during the transition phase is the lack of an impulse stride. The impulse energy transfers energy from the transition phase to the release. The impulse stride is a final cross-over step but with the exaggeration of the right knee drive. The drive of the right knee aids pulling the hips forward (Rogers, 2000). The athlete being analysed performs the cross-over steps with ease but just has no final impulse stride, which gains explosive energy for the release phase. The lack of an impulse stride means there is no vigorous movement generating no pace and explosion.
Fig 5. The image shows the lack of a knee drive. The knee should theoretically be at 90 degree angle. The lack of knee drive reduces the explosive movement of the impulse stride.
Another major weakness from the athlete is during the block phase. As Rogers (2000) explains the left side of the body should be kept firm and act as a block whilst the drive comes from the right hand side, accelerating through the block. The left leg should be fully extended so the right hand side can rotate and drive through the left leg. The weakness the athlete shows is that after the impulse stride the left-leg is planted but is flexed. The implications of this are that the right hand cannot drive through the left side, generating no power for the javelin throw. The flexing of the left knee causes the hips to sink meaning body weight is forced backwards.
Fig. 6 The image shows the lack of block during the release phase. The planting foot should be firm and almost in a vertical line. The flexing of the front knee causes hips to sink and a lack of drive through this block.
Table 1: illustrates the athleteâ€™s strengths and weaknesses.
Good posture in run-up with the javelin kept stable.
Arm drops below plane of the shoulders when drawn back
Uses 10-15 step run-up.
Lack of exaggeration during the impulse step
Palm faces upwards and shoulder externally rotated when javelin is drawn back.
Good footwork during the transition phase, with 3 well performed cross-over steps.
During block phase left-leg not fully extended, causes right side not able to drive through the block.
Hips drop and height lost during the block and release, caused by left-leg not fully extended.
Developing Technique of the Performer
As mentioned in the previous section the three key weaknesses have been prioritised. The weaknesses are; the drop of the arm below the plane of the shoulders when extended back, lack of exaggeration of the impulse stride and lack of extension of the left leg during the block and release phase. Drills now need to be created so technique of the performer is improved, so in turn the end outcome of the throw will be improved. Drills for improving these techniques can be combined together with drills for extension of the arm and lead leg culminated together.
The first practice drill will be a standing javelin throw. This drill is a warm-up drill but can also focus on technical aspects of the throw (Bowerman and Freeman, 1991). The main objective of this drill is to stabilise the arm. As mentioned a weakness of the performer is the dropping of the arm below the plane of the shoulders. To simplify this drill the athlete could use a turbo javelin, this is a lighter javelin aimed at improving technical aspects or even a tennis ball. The athlete should complete about 30-60 standing javelin throws so the action is stereotyped and the athlete gets the kinaesthetic feel of the throw. During this drill the coach should be giving feedback focusing on the arm position, making sure it is above the plane of the shoulders. This drill is focusing on technical aspects so distance and effort should not be an issue the coach has to focus on.
The next progression of the drill aims to perform 3 cross-over steps then perform a throw. This drill despite the introduction of the cross-over steps focuses on the arm position and extension of the lead leg during the release phase. As noticed the athlete during the transition phase lets the javelin drop below the plane of the shoulders, causing an over rotation of the javelin. During this drill the athlete should begin the throw with the arm fully extended to the rear and above the plane of the shoulders. The first stride should then be completed with the left leg and then cross-over step and throw. During the release phase the athlete needs to focus on fully extending the lead leg allowing the right side to be able to drive through the block (Rogers, 2000). The coach should prescribe the athlete to shadow perform this drill and pause as the left leg plants. This will indicate whether the athlete is fully extending the lead leg. Initially this drill should be done at a slow pace to get used to the rhythm of the movements. Once comfortably the intensity and pace of this exercise should be increased. Again this action should be repeated so the movement is stereotyped to the performer. This means the action can be repeated without any conscious thought. To increase the difficulty of the drill the athlete should throw towards a target, making a gate to aim the javelin towards. The athlete should then challenge themselves out of 10 how many times can the athlete successfully land the javelin.
The next drill will focus on the impulse stride. As explained the athlete lacked any exaggeration of the impulse stride therefore lacking explosive power into the release phase. This drill will focus on the high knee drive of the right knee. The athlete will perform cross-over steps over a line of SAQ hurdles. The athlete will only drive the right leg over the 12 inch SAQ hurdles. The will be done so the athlete feels comfortable with the feel and explosive movement of the impulse stride. The athlete should now understand the requirement s of the impulse stride so the final practice should be the athlete performing a 7-11 javelin throw. This will replicate the throw in a competition environment. The coach need to observe all components of the javelin and see if the technique has improved.
The javelin throw according to Rogers (2000) is split into four phases. These phases are; approach, transition, block and release and follow through. Each phase has key aspects which the coach should compare against a good model of the practice, the model of practice I compared the performer to was Steve Backley. By using video-analysis strengths and weaknesses of the performance could be drawn. For the weaknesses progressive and technical practices were drawn up so technique of the performer could improve, therefore improving performance. The key weaknesses of the performer analysed was; dropping of the arm below the plane of the shoulder when withdrawn in the transition phase, lack of extension of the lead leg during the release phase and lack of an impulse stride during the transition phase which is the most explosive movement. The progressive practices focused on one or two key points and are basic and repetitive so the technique can be embedded in the performance. Eventually the practices developed into a practice javelin throw replicating what would be done in competition, so developments can be seen.