Horizontal Jumping 101 Part 2
By: Cameron Gary
In Part One of Horizontal Jumping 101, we dealt with the basics pertaining to horizontal jumping events. The horizontal jumping events (in fact all jumping) have a very close relationship to sprinting. It is no accident that almost all good horizontal jumpers are capable, if not outstanding sprinters. Since we know that sprinting is a series of jumps, let’s look at how we might utilize some of the general principles covered in Part One.
Center of Mass
Horizontal jumping is about the projection of one’s Center of Mass (COM), or “cheating gravity” according to Vern Gambetta. As you may recall, the COM in humans is not a fixed point. If one’s arms or legs move one direction or another, the COM shifts accordingly in order for the body to remain balanced. In throwing-oriented martial arts such as Judo and Aikido, one is rarely .thrown. in a literal sense. It’s not really necessary to actually lift a person in order to “throw” them, per se. Instead the opponent is actually led into a position of extreme instability, from where the technique is applied rather easily. The more one destabilizes one’s opponent, the easier it is to further unbalance and subsequently control them. In fact the opponent actually “throws” himself!
Try this simple test:
Stand erect with straight legs.
Bend forward at your hips and touch your toes (or at least try to…)
Now stand erect with your back to a wall. Your heels and buttocks must touch the wall.
Now bend forward and attempt to touch your toes.
It is almost certain that you were not able to get anywhere near touching your toes on the second attempt. As you bent forward when not standing against the wall, your hips/buttocks shiftedbackwards to accommodate the mass of your torso moving forward. Your COM moved slightly forward, but likely stayed within of your body. However, when you bent forward while against the wall your rearward hips/buttocks movement was restricted. Your COM continued forward well outside your body, most likely well past a point directly above your toes. This caused you to lose your balance forward. Thus, you either 1) took a step forward to regain your balance, or 2) face planted (fell). I hope it was the former and not the latter. I’ll throw in the martial arts lesson for free….
Walking is merely a series of controlled destabilizations ("falls") where the center of mass is “pushed” beyond its balance point (rear leg) then is "caught" by the front foot/leg prior to the rear foot breaking contact with the ground. Running is essentially the same thing, except it is done dynamically as a series of controlled "jumps". The functional difference between a run and a walk is that a walker always has one foot on the ground, whereas a runner’s feet are off the ground during the stride transition. It is important to note that while walking one can get away with putting one’s foot well in front of the COM as the movement is not ballistic. In dynamic movements such as sprinting, we strive to keep the foot strike as close to beneath our COM as possible. Although there is a slight hinged-moment (explained below) phase in sprinting, one should not over-extend forward while sprinting. This would create a large hinged-moment impulse, which changes the athlete’s direction and causes either a definitive jumping movement upward (or sideways as in .cutting. movement in football), or a .braking. movement where one is slows down or stops.
Forward Rotation and the Hinged-Moment Phase
Horizontal jumps are a hinged-moment segmental ballistic-reactive movement. What? That is just fancy talk for saying the body stops at a point, quickly applies force into the ground via the use of swinging body parts, rotates around that point as it continues moving forward and subsequently leaves the ground (hopefully forward and upward). An analogy is the pole-vaulter’s pole as it strikes the plant box, stops at one end, bends and snaps back into its original shape. The energy used to return the pole back to its original shape helps to propel the pole-vaulter upward over the bar. This is the hinged-moment phase. Our primary concern is with how one uses this to project one’s COM linearly and to a certain extent vertically through space in the most efficient and effective manner.
Hinged-Moment Phase
As the jumper comes tearing down the runway at breakneck speeds (hopefully the run is controlled and rhythmic), all of the body parts move as a unit down the runway at the same velocity. As the jumper’s foot strikes the take-off board, the lower part of the body decelerates to accommodate the absorption, impulse and change of velocity from one direction to another (hinged-moment phase). It happens very quickly, but not fast enough to keep pace with the rest of the body. While the upper body continues along its path nearly unobstructed, the lower body lags slightly behind. This causes the body to rotate forwards around the longitudinal axis (runs sideways through your body’s COM, (hip to hip). If unchecked, this rotation will continue unabated and the jumper will literally face plant!
Forward rotation is why coaches advise their athletes to drive quickly off the board, “punch” the leading knee upward, and then strongly kick the lower leg/foot down and back while raising the arms upward. The goal is to produce a counter-rotation in the lower body. As the legs swing backward, the hips have to move forward (action-reaction). The jumper attempts to achieve a long thin shape in the air, as this shape tends to rotate more slowly around the longitudinal axis than a shorter or round shape. The jumper then moves into their preferred flight style, be it a .hang. or a”hitch-kick” (I’ll explain those in a later installment). The main reason for all of the in-air gymnastics is to maintain a relatively upright position with the ultimate goal of achieving an optimal landing position – and nothing else. It should be emphasized that landing position is a result of the movements that precede it. When diagnosing problems in the horizontal jumps, always examine the movement(s) that preceded the problem instead of focusing on the symptom itself.
We do all this just to learn how to stick one’s feet into the dirt? Yep, that’s right. Just to land. Read on…
Momentum
In the horizontal jumps, the biggest determinant of overall distance is horizontal momentum; i.e. "speed". It is not merely leaping ability or vertical height achieved. The theoretical "perfect" jumping take-off angle in the long jump is about 25 degrees instead of a perfect diagonal of 45-degree path. This is due to the athlete’s COM starting its parabolic flight path from a position approximately three feet above ground then ending at ground level. The flight curve is slightly longer and lower on one side of the apogee (highest point) than the other. At normal run-up speeds, even the 25-degree angle is nearly impossible to achieve. In order for an athlete to achieve this angle, one generally has to slow down and apply a large hinged-movement to project the body upward. The loss of speed would be so great it would not justify the extra height gained.
It is more common to see slightly lower take-off angles in the horizontal jumps (the norm is between 18-25 degrees, dependent upon the event). It is more desirable for the athlete to have a flatter parabolic curve with greater horizontal velocity than it is to have a steeper parabolic curve with lesser horizontal velocity. It is wise to teach your athletes to “displace” their COM as much as possible during the take-off(s). “Displacement” is the process of causing your COM to move as far forward past your point of contact (plant foot) prior to foot release during the hinged-moment phase. The trick is to exert force into the ground for as long as possible while conserving momentum. It is easier said than done.
Displacement is one of the reasons why the pole vault has much more in common with the horizontal jumps than the high jump. It is a pointless to have athletes train for excessive height (via jumping over obstacles, striking suspended objects with their head, etc.) while practicing the horizontal jumps. It essentially ruins the muscle movement patterns associated with forwarddisplacement. It also reinforces patterns of movement geared toward high jumping (where we dojump over things). The below figure illustrates why it is much better for athletes to strive to achieve their apogee (highest point of the parabolic curve) later in the jump, as opposed to earlier. The flight path angle is determined at the instant the athlete leaves the ground. Aerodynamics has almost no effect, so the landing angle will mimic the take-off angle. Notwithstanding forward rotation, the athlete’s sole objective is to maximize the parabolic flight path of the COM established at take-off. This is why it is important to learn how to land. You can only land correctly if you “fly” correctly. My recommendation is that horizontal jump athletes be taught to jump "OUT" not "UP".
Why a flatter (and faster) parabolic curve is better
One Last Word on Momentum
Momentum can be a big ally or an enemy, depending on how it is used. Many American triple jumpers (myself included – it’s too bad youth is wasted on the young) felt it was more important to .feel. the power they exerted into the runway. There is nothing wrong with this . as I like strong people . but I have one caveat… I now believe that the best impulse effect is achieved via .skipping. across the runway, such as the way a flat stone is skipped across water. My former coach, Yukito Muraki (Japan’s national jumps coach) espoused this view 25 years ago. John Tansley, an internationally recognized coach and the writer of the Jumps section of the Amateur Athletic Foundation (now LA84) Coaching Manual also shares this view.
All other things being equal, the distance the stone is skipped is dictated by the speed and angle at which it hits the water. In order to maximize this “skipping”, the stone must be thrown at a very high velocity and at a relatively flat angle relative to the surface of the water. The stone does not pick up speed as it goes, as the inertia it encounters (gravity, the water, etc.) takes away its kinetic energy and subsequently, its momentum. However, the triple jumper can maximize his distance via his ability to conserve momentum. This is done two ways: 1) by keeping the jumping and landing angles FLAT; and 2) by utilizing an “active” foot movement. Noted sprint coach Brooks Johnson uses the term “Progressive Aggression” to emphasize the focus on not allowing your energy/concentration to wane at the end of a run. The same principle applies in the horizontal jumps. Rocks don’t have feet so they are incapable of imparting an impulse into the ground. Consequently, I like to emphasize developing and maintaining as much “negative foot speed” (the faster the feet move backwards, the faster the body can move forward) as possible in order to maximize our “progressive aggression”.
Another reason why it’s better to be faster!
Triple Jump World Record Holder Jonathan Edwards demonstrated this .skipping. principle with his performances in 1995 (no one has even remotely approached his performances – which says a LOT). He specifically said that he strove to make his ground contacts as light as possible, much like a stone skipped across water. Biomechanical analysis of his world record efforts showed that he retained more usable velocity through all the phases than any of the other jumpers. It also showed that he had more horizontal momentum during the last five meters of his approach run -thus giving him a "speed reserve" that he used throughout the remainder of the jump. SPEED is a GOOD thing! However, you can’t use it if you don’t have it. Since speed dictates 70- 80% (by most estimates) of jump distance, my feeling is that 70-80% of horizontal jump training should be devoted to the development and maintenance of speed into and throughout the take-off(s).
REFERENCES:
AAF. 2007. AAF Track and Field Coaching Manual. Los Angeles, CA; Amateur Athletic Foundation of Los Angeles
Bullard, E. and Knuth, L. 1977. Triple Jump Encyclopedia. Pasadena, CA; The Athletic Press Chu, D. 1998. Jumping into Plyometrics. Champaign, IL; Human Kinetics Dintiman, G. and Ward, B. 2003. Sports Speed (3rd Edition). Champaign, IL; Human Kinetics
Dyson, Geoffrey. 1986. The Mechanics of Athletics (8th Edition). New York, NY: Holmes & Meier Publishers
Ecker, T. 1985. Basic Track and Field Biomechanics. Los Altos, CA; Track & Field News, Inc. Gambetta, V. 2007. Athletic Development. Champaign, IL; Human Kinetics
Jacoby, E. and Fraley, B. 1995. The Complete Book of Jumps. Champaign, IL; Human Kinetics Cissik, J. 2003. Strength Training for Track and Field. Mountain View, CA; Tafnews Press
Tafnews Press/Jarver. J. 2000. The Jumps; Contemporary Theory Technique and Training (5TH Edition). Mountain View, CA; Tafnews Press
United States Track and Field Coaching Education. 2005. Level 1 Curriculum. Indianapolis, IN; USA Track & Field, Inc.
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About The Author:
Cameron is a long-time horizontal jump coach from the San Diego area. He is currently the jump coach at Monte Vista High School in Spring Valley, CA. Cameron formerly coached the horizontal jumps at Helix High School in La Mesa, CA from 1980-81 and 2004-2006; as well as at San Diego State University from 1985-87. In the past four years, Cameron has qualified three different athletes for the California State championships in the horizontal jumps. Cameron also coached the California State JUCO Champion in 2005. The previous year, this athlete also finished 4th in triple jump at the National Junior Olympics. Cameron currently serves as an advisor and consultant to numerous high school, collegiate and elite athletes and coaches throughout the country. Cameron also is a coaching clinic presenter for the Amateur Athletic Foundation of Los Angeles (now called LA84). LA84 is an organization subsidized by proceeds from the 184 Olympics, whose mission is to provide coaching education opportunities to youth, high school and collegiate coaches throughout Southern California. Cameron can count among his endorsers Arnie Robinson (1976 Olympic Long Jump Champion), John Tansley (world-renowned jump coach) and Larry Knuth (another world renowned jump coach and author of the ”Triple Jump Encyclopedia”).
During his competitive days, Cameron was standout long jumper and triple jumper at Helix High school. While at Helix in 1978, Cameron broke the Conference meet record in the Long Jump (23.4.5.) that had previously stood for 15 years. He went on to San Diego State University where he broke the Triple Jump school record in 1983 (53’ 2.75"). Cameron was the Western Athletic Conference Triple Jump champion that year and he also qualified for the NCAA Championships. Cameron subsequently qualified for the United States National Championships in 1983, 84 and 85, as well as the United States Olympic Trials in 1984. Since 1985, Cameron has worked as a law enforcement officer in Southern California. He was the California Police Olympics (Now the Western States Police & Fire Games) Champion in the Long Jump and Triple Jump in 1989, 90, 91, 92, and 93. Cameron was also the World Police and Fire Games champion in the Long Jump and Triple Jump in 1989. Cameron is still the Western States Police & Fire Games meet record holder in the Triple Jump (50’ 2" from 1989).
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