What are the key biomechanics involved in a successful long jump?
The execution of long jump is comprised of flight and contact phases. There are three key components for a successful long jump: the run up; the take-off; and the landing.
The run up is the most critical element in the whole as it establishes velocity for distance and therefore is a limiting factor for attaining greater jumping distances (Hay, 1993). Therefore the long jump approach run should be executed in such a way that it brings the jumper to the takeoff point accurately and with the highest possible speed. Olympic medallist and World Champion long jumper Mike Powell supports this claim:
“The distance comes from the speed…I believe that the approach is 90 percent of the jump. It sets up the rhythm, it sets up the takeoff, and that’s really the majority of the work. Once you leave the ground this whole distance that you can go is already pre-determined (by) the amount of speed you have at takeoff, your hip height, takeoff angle and the amount of force you put into the ground.”
This video of Mike Powell's Olympic Gold performance illustrates the rhythm executed by elite athletes in the run up and its influence on the distance achieved:
During the take-off phase of the long jump, highly stretched leg extensor muscles are able to generate the required vertical momentum. Thereby, serially arranged elastic structures may increase the duration of muscle lengthening and dissipative operation, resulting in an enhanced force generation of the muscle-tendon complex. (Seyfarth, Blickhan, & Van Leeuwen, 2000). To obtain maximum performance, athletes run at maximum speed and have a net loss in mechanical energy during the take-off phase.
Does technique override the speed of the run-up in achieving optimum distance?
In this video the two long jumpers utilize a different method in the run up but achieve similar results. Therefore the question arises, what role does technique play in achieving distance in a long jump?
The effect of run-up speed on long jump performance has been studied extensively in the last two decades. Wide research has shown and confirmed the long-held suspicion that indeed the faster the run up, the farther the jump: therefore the run-up speed has been identified as having the strongest correlation with jump distance in the overall performance (Hay et al. 1986; Hay, 1993; Lees et al.,1993; 1994). Bridgett, Galloway & Linthorne (2002) investigated the effect of run-up speed on long jump performance undertaking a study to analyse other factors such as training for technique and muscle mass. The results from the technique intervention study confirmed the pivotal role of speed work in the training program of the long jump athlete: the faster the athlete's run-up, the farther the athlete will jump. Whilst training for long jump technique may not see as much improvement, a long jumper may improve their overall distance by improving their run-up speed. This can be achieved by using a better running technique or by increasing the strength of the muscles used in sprinting (or by a combination of the two). This particular study proved this theory to be true as it indicated a rate of improvement of 8 cm per 0.1 m/s increase in run-up speed. The paper contends that the trend from the technique intervention study indicates the improvement to be expected solely through better running technique, not an all-encompassing long jump technique. During the technique intervention study, the muscular strength of the athlete did not change, and so the trend line must therefore indicate the improvement to be expected through better running technique. In conclusion run-up speed has a strong influence on long jump performance; therefore to achieve greater distance via higher speeds generated in the run up, speed training and strength training are essential components of a long jumper’s training program.
The Take-off Phase: optimizing jumping performance
As it is well known (Hay, 1993) the most influential factor for jumping distance is the running speed. However research on long jump models have predicted also that a certain angle of attack of the leg optimises jumping performance (Alexander, 1990); This optimum requires a relatively low minimal stiffness of the leg.
Results from a study conducted by Linthorne, Guzman, & Bridgett (2005) established that the peak take-off angle for a long jumper can be predicted by combining the equation for the range of a projectile in free flight with the measured relations between take-off speed, take-off height and take-off angle for the athlete. Taking this information into account it is understood that there is no solid textbook approach for takeoff angle as it varies on the constraints of each long jumper individually.
During the human long jump energy is in fact largely conserved. Nevertheless, due to the high running speed, the first so-called passive impact immediately after touch-down strongly influences the system dynamics. It is impossible to avoid the impact generated during touch-down on the marker board. However, long jumpers take advantage of the force generated during the impact by actively driving the jumping leg onto the board. By this measure the passive peak, especially in the vertical component of the ground reaction force, is increased. Despite the fact that the generation of this peak clearly absorbs energy it enhances vertical momentum, as illustrated in Newton's First Law, which is important to achieve long jumping distances.
Touchdown: facets of successful landing
When it comes to landing efficiently, the movements and actions occurring whilst in flight are fully responsible for the execution of a stable landing (Herzog, 1986). The objective of the flight phase of a long jump is for the athlete to maneuver into a position that allows for an optimal landing that is both stable and achieves maximum distance. Whilst the landing distance is significantly influence by the speed of the run up, the quality of the landing distance is dependent on the body position when the athlete makes ground contact. This is because the athlete possesses some angular momentum and he rotates in the air during flight in the long jump. Angular momentum, which is the product of the moment of inertia and angular velocity, changes the momentum of the athlete mid-flight and has a tendency to rotate the athlete clockwise (Blazevich, 2012).
There are many techniques that athletes use in the long jump to achieve a better landing, including the sail jump, 2½ and 3½ hitch kick, and hang jump. In a study conducted by Bouchouras, Moscha & Paiakovou (2009) the hang style and 2½ hitch kick style was compared in relation to the amount of angular momentum and the efficiency of landing in order to determine the factors that lead to a better landing in the long jump. It was hypothesized that the 2½ hitch kick would produce greater angular momentum at the moment of take-off, therefore enabling the athlete to a execute a better landing as the technique lands the heels closer to the centre of mass and simultaneously lands the pelvis closer to the heels.
Here is a video demonstrating the 2 1/2 hitch kick:
The Hitch Kick:
This image illustrates the multiple phases of the long jump. Note the hitch-kick technique followed by the body maneuvering into a position where the torso is vertical and the legs are almost at a right angle to the upright midsection.
In the long jump, the hitch-kick technique utilises whole body motion through forward rotations of the arms and legs whilst mid-air; this is to counteract the forward motion of the body as a consequence of torque created by the horizontal ground reaction force (Blazevich, 2012). At the moment of take-off, the vertical ground reaction force is behind the athlete’s centre of mass; therefore the angular momentum during flight is considered stable and cannot be changed. In order to retain balance in the air, the athlete can either increase the moment of inertia, decreasing the angular velocity, or with the appropriate motion of arms and legs the athlete can transfer the angular momentum of the body to their segments, ultimately allowing the legs to prepare for landing (Bouchouras, Moscha & Paiakovou, 2009).
One particular facet of the hitch-kick technique that separates it from other techniques is the leg cycling. Optimum leg cycling whilst the athlete is in flight not only increases the stability upon landing but also contributes to achieving maximum landing distance (Blazevich, 2012). By extending the legs forward in an almost horizontal position with an upright torso maximal landing distance is increased.
Not just 'run and jump':
It is clear after analyzing many research studies into long jump and analyzing their results that long jump is not merely the athletics events which requires a standard 'run as fast as you can and jump' approach. Although it is usually presumed by amateurs athletes, parents or school children that the speed of the run up ultimately influences the distance attained, research indicates that there are several other facets that, when executed effectively, combine to achieve a stable and extensive landing.
Within the run up, flight and landing phases there are individual features that have the capacity to influence the jump's success. Factors such as the speed of the run up, the angle of take off, in flight bodily maneuvers into a specific position, and landing safely are all important considerations that athletes, whether amateur or professional, should take into account. However for some primary and secondary school students they are not taught the fundamental biomechanical principles of the long jump and their focus is instead redirected to the run up and placement of feet on the take-off mat.
The processes of long jump are complex, especially for the younger athletes, therefore a standing long jump approach is implemented:
However this technique incorporates other facets which are relatively unrelated to the technique required to successfully execute a long jump. Standing long jumps focus primarily on lower body strength and use of arm movement to propel the body forward, and fails to take into account the role of speed and flight techniques that are necessary when progressing to a standard long jump. It is critical for physical educators to have the knowledge underpinning the necessary facets of the long jump not only to allow for students and athletes to achieve their potential but also to prevent injury and harm to athletes (Fagenbaum & Darling, 2003). The emphasis should once again be taken away from teaching the textbook methods of athletics and embrace the biomechanical movements supported by decades of research and studies. Athletes of the future should no longer emphasis the 'run and jump' or solely aim to not step over the marker; our athletes should now have the information to soar ... biomechanically accurately.
References:
Alexander, R. M. (1990). Optimum take-off techniques for high and long jumps. Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences, 329(1252), 3-10.
Bouchouras, G., Moscha, D., & Paiakovou, G. (2009). Angular momentum and landing efficiency in the long jump. European Journal of Sport Science, 9(1), 53-59.
Bridgett, L. A., Galloway, M., & Linthorne, N. P. (2002). Optimum takeoff angle in the standing long jump. Paper presented at the The 4th Internation Conference on The Engineering of Sport, Kyoto.
Fagenbaum, R., & Darling, W. G. (2003). Jump Landing Strategies in Male and Female College Athletes and the Implications of Such Strategies for Anterior Cruciate Ligament Injury. American Journal of Sports Medicine, 31(2), 233-240.
Hay, J. G., Miller, J. A., & Cantera, R. W. (1986). The techniques of elite male long jumpers. Journal of Biomechanics, 19, 855-866.
Hay, J. G. (1993). The biomechanics of sports techniques (4 ed.). University of Michigan: Prentice-Hall.
Herzog, W. (1986). Maintenance of body orientation in the flight phase of long jumping. Medicine and science in sports and exercise, 18(2), 231-241.
Lees, A., Fowler, N., & Derby, D. (1993). A biomechanical analysis of the last stride, touchdown, and takeoff characteristics of the women's long jump. Journal of Sports Sciences, 11, 303-314.
Lees, A., Graham-Smith, P., & Fowler, N. (1994). A biomechanical analysis of the last stride, touchdown, and takeoff characteristics of the men's long jump/. Journal of Applied Biomechanics, 10, 61-78.
Linthorne, N. P., Guzman, M. S., & Bridgett, L. A. (2005). Optimum take-off angle in the long jump. Journal of Sports Sciences, 23(7), 703-712.
Rosenbaum, M. (2014). World Champion Mike Powell's Step-By-Step Long Jump Tips. Retrieved June 20, 2014, from http://trackandfield.about.com/od/longjump/p/powelljumptips.html
Seyfarth, A., Blickhan, R., & van Leeuwen, J. L. (2000). Optimum take-off techniques and muscle design for long jump. Journal of Experimental Biology, 203, 741-750.
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