Thursday, 23 June 2016
Introduction
The blog aims to define the key skills and phases that are needed to correctly and successfully complete the triple jump. There are specifically four phases that are used during the triple jump and many various important techniques that can be used to improve the jump. Throughout our discussion of triple jump phases and techniques, we will be discussing the biomechanic patterns, concepts and outcomes needed to create optimal performance outcomes. Our focus on explaining these skills will be through the breakdown of an elite athletes technique and a developing junior athletestec technique. we will investigate how the junior athlete can improve his optimal technique through biomechanics.
Elite triple jumpers have a 37-50 metre run up which usually consists of 17-26 steps. Contrasting to other Olympic events like long jump or high jump, triple jump has three consecutive take offs that require athletes to execute with coordination even though many parts of the body are under stress.
Triple Jump phases
Approach/lead up phase- The aim of the approach steps is for athletes to reach their maximum speed, which they will maintain throughout the remaining sequences until they land (Blazevich, A. 2010). The first step of the phase sees athletes apply a force in the horizontal direction in order to begin the forward motion. Horizontal velocity is the rate at which an object is travelling parallel to the earth (Blazevich, A. 2010). Horizontal velocity is acquired during the approach and is lost primarily due to ground contact during the three phases (Antonini 2015). Preservation of velocity can be achieved by using the correct take-off technique during each phase. Triple jumpers face the difficulty in maintaining the propulsive force during the take- off and landing in the phases. This is supported by Newton’s First Law, an object at rest will stay at rest, and an object in motion will stay in motion, unless acted upon by another force (Blazevich, A. 2010). The athlete starts at a 45-degree angle to the ground so they can push themselves forward. The first 6 strides of the triple jump involve maximal effort in order to reach maximum speed. The power is driven from the legs and hips which is influenced by Newton’s Third Law. For every reaction, there is an equal and opposite reaction (Blazevich, A. 2010). The athletes’ foot is the action force and the movement down the runway in the reaction force. It is beneficial for athletes to attain a high speed, as they need to carry this speed with them throughout the rest of the movement phases. After the initial 6 strides, the athletes posture will become tall and erect, which the hips beneath, similar to the posture of a sprinter (Blazevich, A. 2010). This is an ideal technique as in this position, the body can generate force for the next skip, hop and jump phases (Blazevich, A. 2010).
An elite triple jumper will show many characteristics similar to a great sprinter. In the moment prior to one foot touching the ground, it is already extended and the other knee is directly in line with the extended knee. More time can be used to produce a propulsive impulse as there is a large distance between each point of contact with the ground (Blazevich, A. 2010). Angular momentum is a function of moment of inertia and angular velocity. The moment of inertia is a product of the distribution of weight in the leg away from the primary point of torque production (hips). The greater the moment of inertia, the greater the force needed to move the leg. The moment of inertia can be manipulated to help minimize the force needed to move the leg (Blazevich, A. 2010). This is done by the jumpers having large powerful quadriceps but minimal the weight in their calves. The leg muscles hold greater mass in jumpers as they create the velocity used for the jump. In triple jump, mass is used particularly in the hop, skip and jump phases (Blazevich, A. 2010).
Hop phase- The hop phase is the continuation of the movement pattern showed during the run up. The arms are slightly slower and the legs are slightly slower and elongated, but the speed remains the same. The take-off for the hop and step phases are taken from the safe foot, consequently it is argued that the optimal body positions are the same or similar (WU, W., WU, J., LIN, H., & WANG, G. 2003). To propel the jumper, a vertical ground reaction force is created. Wu et al (2003) states that the angular momentum of the athlete at the take off point should be zero. The optimal trajectory is relative to personal characteristics of the athlete and also the speed in which they take off. This articulates the importance of maintaining speed from the last steps of the approach phase into the hop phase. The rowing of the arms helps to reduce the amount of momentum and to keep it consistent. It also helps to rotate the body rotate back to a neutral position so the athlete is ready for landing. Jumpers are unable to look down at the board prior the jump as this interferes with the body position. If this occurs, the jump will be shorter or the athlete may fall over. The foot should land slightly in front of the jumpers centre of mass. Excessive front-side placement of the foot produces deceleration or even injury (Blazevich, A. 2010).
The ground reaction force is when a person applies on the ground, the ground applies a force of the same intensity and opposite direction on the person. An example of this is when gymnasts land after their routine. Their body needs to be able to absorb the force the ground has given back once they land (Blazevich, A. 2010).
In the hop phase, there are two technical components, the hop leg cycle and the free leg cycle. The hop leg cycle is the action of the leg that executes the take-off from the board and take off into the step phase. The free leg cycle is the movement of the other leg during the flight phase of the hop. Novice athletes aggressively pull the leg forward, destroying the reflexive nature of the movement. This evokes the body’s flexion reflex and produces forward tilt of the pelvis. This technique will negatively affect results as velocity is lost through the hips and resulting in a lower angle of take-off (Blazevich, A. 2010).
At the completion of the hop, a small amount of front side distance is needed to create proper lift into the step phase. The front side distance at the hop landing is be excessive, correct or insufficient. Premature planting of the foot is a strategy used by jumpers to overcome instability (Blazevich, A. 2010).
Skip/step phase- After the landing of the hop phase, the step phase involves the athlete taking an elongated step. This requires the athlete to take off at the optimal angle, thrust both arms forward and holding their posture and position at the top of the step. Angular motion is a mass moving at an angular velocity (Blazevich, A. 2010). Within the skip phase, angular momentum is evident in both the swinging of the arms and legs. The legs need to swing back quickly in order to increase torque developed by the hip muscles which makes the jumper move forwards. The time in which muscle force is developed allows higher velocities due to the change in angular momentum of the leg being greater. The body is propelled in a forward manner by swinging both arms forward as this results in greater angular momentum (Blazevich, A. 2010).
Posture and swing elements are critical in “holding the step”. Holding the step is when athletes keep their legs and powerfully explode them outsides to maintain momentum.
The sequence of skills; tall and neutral body posture, pelvis posture, the thrusting of the free legs and arms, and a strong lift of the swing leg, collaboratively allow the desired distance of the step phase to be achieved (Blazevich, A. 2010). A tall and upright position will mean that a longer jump can be performed as the centre of mass is in the correct position. Before the landing, the support foot extends to maximum length to increase the distance acquired in the step. The swing leg moves at the same time as support/take-off foot lands in preparation for the jump phase. The arms swing forward simultaneously towards the swing leg to reduce momentum lost (Blazevich, A. 2010). Upon impact with the sand, the ground applies an equal and opposite force against the jumper after the foot applied a forward force in a downward motion. Breaking force needs to be minimised in order to prevent the loss of speed. This can be done by the forward directed force of the foot off the ground providing a propulsive impulse. This maximises propulsion and minimising the breaking forces (Blazevich, A. 2010).
The sequence of skills; tall and neutral body posture, pelvis posture, the thrusting of the free legs and arms, and a strong lift of the swing leg, collaboratively allow the desired distance of the step phase to be achieved (Blazevich, A. 2010). A tall and upright position will mean that a longer jump can be performed as the centre of mass is in the correct position. Before the landing, the support foot extends to maximum length to increase the distance acquired in the step. The swing leg moves at the same time as support/take-off foot lands in preparation for the jump phase. The arms swing forward simultaneously towards the swing leg to reduce momentum lost (Blazevich, A. 2010). Upon impact with the sand, the ground applies an equal and opposite force against the jumper after the foot applied a forward force in a downward motion. Breaking force needs to be minimised in order to prevent the loss of speed. This can be done by the forward directed force of the foot off the ground providing a propulsive impulse. This maximises propulsion and minimising the breaking forces (Blazevich, A. 2010).
Jump / landing phase-The aim of an effective take-off is the cooperation between a good gain in vertical velocity and a minimal loss of horizontal velocity. Maintaining velocity can be achieved by rotating the core and hips, maintaining wider angles between knees and legs and keeping legs lifted (Blazevich, A. 2010). Athletes aim to reduce any non-essential time their foot spends touching the ground. Triple jumpers strike the ground with a fore-foot/mid-foot strike which reduces the power and amount of force lost. Any additional time or body part that impacts the ground, if velocity lost which results in a shorter flight time (Blazevich, A. 2010). The following steps assume the jumper has landed the step phase correctly in an upright position with an extended leg to increase the distance of the step. The athlete will swing their arms and free leg whist rolling and thrusting their body(Blazevich, A. 2010).Their chest, knees and arms will be moving in an upward and forward motion to reach an optimum maximum height. Reaching the optimum maximum height will mean the athlete maintains a central centre of gravity (Blazevich, A. 2010). This will make the jump more stable and produce the most amount of velocity to propel them forward. The next sequence of movements sees the knees being pulled in closer to the chest and the arms being swung down similar to a paddling motion (Blazevich, A. 2010). This will further propel the jumper forward whilst the body position is kept upright, legs outstretched and feet flexed to avoid touching the sand. Once ground contact is established, the jumper rolls their body forward even more to ensure their core touches the contact site of the feet. Rolling the body forward results in no ground being lost from the landing so the full jump can be measured (Blazevich, A. 2010).
Elite Athlete - Christian Taylor
The 2015 world championships record holder for Triple Jump is Christian Taylor. ("About Christian", 2016) He accomplished a triple jump record of 18.21 meters in Bejing, winning the championship. To execute triple jump Taylor would have trained to master his technique, achieving an optimal phase sequence and body trajectory. Video evidence of this jump is below and displays the optimal biomechanics technique needed to complete triple jump at an elite level. ("About Christian", 2016) Taylor uses trained techniques to achieve the record, representation of the optimal techniques is evident. It is important to remember that all techniques used to improve a set of skills like this depend on the personal athletic ability of a person. It is also important to know that Taylor is trained in long jump and relay events at an elite level. ("About Christian", 2016)
While watching Taylor complete the triple jump, it is easy to break down the skill into phases. The lead up phase, hop phase, skip phase, jump phase and landing phase. By breaking down and looking at these, we can assess what the optimal biomechanics technique for triple jump is and how it can be developed.
(Christian Taylor 2015 Bejing World Championships, 2015)
While watching Taylor complete the triple jump, it is easy to break down the skill into phases. The lead up phase, hop phase, skip phase, jump phase and landing phase. By breaking down and looking at these, we can assess what the optimal biomechanics technique for triple jump is and how it can be developed.
(Christian Taylor 2015 Bejing World Championships, 2015)
Comparison of elite Athlete and junior training Athlete
Using the comparison of an elite athlete and a training junior athlete allows us to see the difference in optimal technique. How the phases can be altered to assist the junior athlete to develop their phases and become optimal in their performance technique can occur.
(Christian Taylor Triple Jump Training, 2016)
Christian Taylor - Taylor uses a unique technique, specifically developed for him to achieve the perfect triple jump through each phase and landing, allowing him to execute the jump. Taylor uses a strong approach/drive, long strides and a powerful body trajectory to hurl himself across the line and into the pit to assist him in this execution.
(NSW Little Athletics State Championships, 2010)
By viewing the young under 13 triple jump competitor, we can visually see that the biomechanics principals are beginning to be developed and used but they have not reached a peak to achieve the optimal biomechanical phase. Age is a factor needing be considered in the comparison first, Christian Taylor is 25 and the competitor here is between the ages of 11-13, still developing. As for phase technique; the approach/drive phase is not visible at the beginning of the footage however we can assume a similar stride is used to the athletes but a smaller interpretation of the professional model of the phase. As for the running part of the phase, we view a small moment of the athlete using their hands and arms pushing power forward and continuing the momentum of the beginning stride (Eissa, 2014). Entering the hop phase, Taylor clearly uses a higher amount of body trajectory to gain his momentum. The junior athlete is of slim build. This can affect the amount of body trajectory used as when he is in the hop phase, he does not carry as much momentum through his body in the air. Professional athletes carry quite a bit of body mass in their lower trunk, contributing to the amount of force carrying them forward (Eissa, 2014). Another contributing factor is the maximum speed achieved during the approach/drive phase. We cannot calculate if the athletes speed at this time in the videos or the lack of force. These two factors are important as the amount of force the athlete applies to the ground will propel them upwards in momentum (Eissa, 2014). Landing the hop phase and moving into the skip phase, the athletes foot must touch the ground using the ball of the foot. In Taylor's video this is evident and precisely timed to minimise the amount of force lost to the ground when the step is completed. The junior athlete's step phase looks quite flat footed and short in distance. Loosing distance means overall momentum is lost affecting the following phase. It can be presumed that the junior athletes timing of the skip phase would not be perfectly timed at this point in training. Triple jump is crucially dependent of the timing of foot to ground contact (Eissa, 2014). The jump phase is dependent on the speed and momentum of the phases before. Taylor has carried his speed through each phase and travelled a great distance. Taylor approaches the jump phase using his arms for further momentum by swinging them upwards as he jumps. This double arm swing raises the centre of mass which allows for an increase in kinetic energy at each take off (Allen, King & Yeadon, 2010). When Taylor leaves the floor for a final time his knees pull in towards his body, remaining upwards. When the landing phase begins to occur, Taylor swings his arms backwards in a rowing motion and his legs push back out to land. To complete the landing, Taylor propels his body towards his feet in a sliding motion. The junior Athlete approaches the jump phase with less momentum as discussed in the skip phase. The junior Athlete doesn't execute the vertical height in his arm swing. His arms swing forwards but not upwards enough to carry his body forward further. The junior athletes knees are tucked up but as his body is not vertically up, the knees do not move as high shortening momentum again (Eissa, 2014). During the landing phase the arms do not swing as far backwards, the rowing motion is not as evident. The legs do not extend out to land but catch the athlete under. Due to the lack of momentum the junior athlete has no room to propel forward and create a further distance, instead he stops short. Triple jump is a technical and timing based skill. Without the combination of each phase executed effiecntly and momentum transferred through each phase, the triple jump would not be completed correctly (Eissa 2014).
(Christian Taylor Triple Jump Training, 2016)
Christian Taylor - Taylor uses a unique technique, specifically developed for him to achieve the perfect triple jump through each phase and landing, allowing him to execute the jump. Taylor uses a strong approach/drive, long strides and a powerful body trajectory to hurl himself across the line and into the pit to assist him in this execution.
By viewing the young under 13 triple jump competitor, we can visually see that the biomechanics principals are beginning to be developed and used but they have not reached a peak to achieve the optimal biomechanical phase. Age is a factor needing be considered in the comparison first, Christian Taylor is 25 and the competitor here is between the ages of 11-13, still developing. As for phase technique; the approach/drive phase is not visible at the beginning of the footage however we can assume a similar stride is used to the athletes but a smaller interpretation of the professional model of the phase. As for the running part of the phase, we view a small moment of the athlete using their hands and arms pushing power forward and continuing the momentum of the beginning stride (Eissa, 2014). Entering the hop phase, Taylor clearly uses a higher amount of body trajectory to gain his momentum. The junior athlete is of slim build. This can affect the amount of body trajectory used as when he is in the hop phase, he does not carry as much momentum through his body in the air. Professional athletes carry quite a bit of body mass in their lower trunk, contributing to the amount of force carrying them forward (Eissa, 2014). Another contributing factor is the maximum speed achieved during the approach/drive phase. We cannot calculate if the athletes speed at this time in the videos or the lack of force. These two factors are important as the amount of force the athlete applies to the ground will propel them upwards in momentum (Eissa, 2014). Landing the hop phase and moving into the skip phase, the athletes foot must touch the ground using the ball of the foot. In Taylor's video this is evident and precisely timed to minimise the amount of force lost to the ground when the step is completed. The junior athlete's step phase looks quite flat footed and short in distance. Loosing distance means overall momentum is lost affecting the following phase. It can be presumed that the junior athletes timing of the skip phase would not be perfectly timed at this point in training. Triple jump is crucially dependent of the timing of foot to ground contact (Eissa, 2014). The jump phase is dependent on the speed and momentum of the phases before. Taylor has carried his speed through each phase and travelled a great distance. Taylor approaches the jump phase using his arms for further momentum by swinging them upwards as he jumps. This double arm swing raises the centre of mass which allows for an increase in kinetic energy at each take off (Allen, King & Yeadon, 2010). When Taylor leaves the floor for a final time his knees pull in towards his body, remaining upwards. When the landing phase begins to occur, Taylor swings his arms backwards in a rowing motion and his legs push back out to land. To complete the landing, Taylor propels his body towards his feet in a sliding motion. The junior Athlete approaches the jump phase with less momentum as discussed in the skip phase. The junior Athlete doesn't execute the vertical height in his arm swing. His arms swing forwards but not upwards enough to carry his body forward further. The junior athletes knees are tucked up but as his body is not vertically up, the knees do not move as high shortening momentum again (Eissa, 2014). During the landing phase the arms do not swing as far backwards, the rowing motion is not as evident. The legs do not extend out to land but catch the athlete under. Due to the lack of momentum the junior athlete has no room to propel forward and create a further distance, instead he stops short. Triple jump is a technical and timing based skill. Without the combination of each phase executed effiecntly and momentum transferred through each phase, the triple jump would not be completed correctly (Eissa 2014).
What can a developing junior Athlete do biomechanically to improve his understanding of optimal technique?
Approach- Will Claye is a trained elite athlete who breaks down the triple jump into his optimal techniques to assist future athletes in their training. In a description of his approach, Claye states that it is dependent on the track and the tail wind but on average uses an 18 step run up. The stronger the tailwind the further back he steps and the stronger the headwind, the further forward. Understanding the environmental effects of the surroundings of an athlete can be beneficial or detrimental to the results. ("What You Don't Know About: Triple Jump | By Will Claye", 2015) Junior athletes should familiarise themselves with an approach step count that allows them to build enough power and momentum to be able to transfer it through the phases.
Timing-
Eissa (2014), conducted a study on horizontal velocity in relation to distance covered in triple jump and the take off phases. The horizontal velocity of the 3 take off phases the hop, skip and jump are between 8.4 – 8.86, 7.58 – 8.22, and 6.46 – 7.34 (m/s), respectively. (Eissa 2014) The study had a focus on the loss of horizontal velocity from when the foot touched the ground, results showed that the loss was between 0.69 – 0.95, 0.38 – 0.52, 0.85 – 1.05 (m/s), respectively.(Eissa 2014) They also measured a take off angle of between 15.02–16.0°, and 9–12.7° (Eissa 2014). The research showed that to minimise the loss of velocity, proper take off technique at each phase should be utilised. The challenge of this for triple jumpers is how to continue to move momentum forward during this repetitive task of landing and taking off (Eissa 2014). Claye talks in reference to this stating that 'slight changes could lead me to foul — even a toenail over the end of the board means the jump isn’t valid.' Hay et al discusses research of the University of Iowa in reference to the horizontal distance and the centre of gravity. The centre of gravity lies in the toe of the touchdown foot in each phase and in the landing mark. Without correct centre of gravity in the touchdown between each phase, the athlete would simply decrease their amount of flight and the lack of horizontal distance made during the phases and in the final jump (Hay & Miller jnr., 2016). Claye supports this stating that 'we constantly practice, if you don’t, one of two things will happen: if you’re lucky, you just won’t jump very far because your centre of mass is in the wrong position. If you’re unlucky, gravity will push you forward and instead of landing on your feet, you’ll fall on your face.' ("What You Don't Know About: Triple Jump | By Will Claye", 2015) Junior athletes should approach the timing in the phases of training as the most important as the timing will affect the success of the jump and prevent fouls. Training specifically to improve horizontal velocity and focussing on the centre of gravity in landing will give the junior athlete an advantage in understanding the optimal technique.
Optimal technique in triple jump is reliant on specific timing and the ability to transfer power of motion and momentum. The transfer of momentum occurs through the takeoff foot and transfers into the hop phase takeoff foot, then the skip/step phase takeoff foot then finally the jump phase takeoff foot. Athletes should use the mid part of their foot to complete the take off and continue the power of momentum forward and into the next phase (Hay & Miller jnr., 2016). Repetitive training and the understanding of the positioning of the foot is essential to the optimal technique. Claye explains his own experience; 'Visual cues come in handy, but at the end of the day, muscle memory is king. I’ve done thousands of repetitions.' ("What You Don't Know About: Triple Jump | By Will Claye", 2015)
The laws of motion are effective throughout triple jump but especially throughout the flight of the phases. Claye likens this in his explanation to an ice skater that during a turn, opens up to slow dow ("What You Don't Know About: Triple Jump | By Will Claye", 2015). In triple jump, the athlete must extend their legs to slow down the rotations and remain in the air as long as possible to prepare for the landing and the next phase. No unnecessary motion is needed or created as it will affect the distance travelled. The movement of the legs and arms throughout the phases is crucial to injury prevention ("What You Don't Know About: Triple Jump | By Will Claye", 2015). Specifically speaking of the skip phase, Claye describes the skip phase landing as terribly dangerous as the landing brings with it 15 times his own body weight. While bringing his legs in together then allowing them to explode out towards the landing - again to slow down- Claye also moves his arms backwards during this phase and as the landing approaches, then explosively moves them forward to maximise momentum ("What You Don't Know About: Triple Jump | By Will Claye", 2015). 'If your timing and rhythm aren’t on point, it’s going to hurt. Bad. With all that force, landing wrong could blow out your knee or roll your ankle. Or you might fall on your face, which is painful and embarrassing ("What You Don't Know About: Triple Jump | By Will Claye", 2015)'.
The angle of the body from the jump phase to the landing phase is also vitally important. When taking off for the jump, both legs extend in front of the body to achieve the closet to a 90 degree angle as momentum and core strength will allow. The arms extend past the legs behind the body. ("What You Don't Know About: Triple Jump | By Will Claye", 2015)Landing is difficult to master as gravity pulls you down and first instinct in to use your hands to catch the landing. Instead, the bottom will catch the landing and slide, the jump is measured by the landing point. If hands land behind the bottom, that is where they measure from. Maintaining the closest 90 degree angle is therefore vitally important as it will assist in achieving a further landing.
Junior athletes can approach their training with a biomechanics knowledge that will ultimately help them understand the importance of the fundamental skills they are training in. Claye mentions the importance of training in core strength, bounding, ladder work and track work ("What You Don't Know About: Triple Jump | By Will Claye", 2015).
Conclusion
In comparing techniques between elite athletes and junior athletes it is clear that the focus of biomechanics is important. The elite level athlete is an elitist through their training and understanding of the triple jump. Junior athletes are trained for skill development not necessarily optimal technique and biomechanics. It is these two things that contribute to gaining a better understanding of triple jump.
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