its amazing though, i have numbers from pro meets with guys taking off at 10.5m/s and jumping 8m and guys losing a metre per second at the board, taking off at 9.8m/s and still jumping 8m. Its an amazing event…i think whatever speed you have as long as its around 10m/s, just work work work at your take off and power and you can jump 8m…
its amazing though, i have numbers from pro meets with guys taking off at 10.5m/s and jumping 8m and guys losing a metre per second at the board, taking off at 9.8m/s and still jumping 8m. Its an amazing event…i think whatever speed you have as long as its around 10m/s, just work work work at your take off and power and you can jump 8m…
I think the discrepancy is attributable to a couple things (in rough order):
*How effectively the person lands. Someone who controls rotation in flight and lands very effectively can actually get a mark beyond what they’ve displaced their COM in flight. Likewise, an athlete could land like Marion Jones due to uncontrolled rotations and get a mark that is actually much less than what the projectile motion equations would suggest.
*Variations in takeoff angle.
*Differences in how far the hips are in front of the takeoff foot at the moment of takeoff. It isn’t until the foot leaves the ground that the projectile motion parameters come in to play SOOOO if someone who had a 1.5m inseam jumped against someone who had a 1m inseam the person with the larger inseam would have a fairly sizable advantage before they even left the ground because they could move their hips further in front of the takeoff foot. This inseam advantage would also have an effect on my first point.
*Minor variations between jumpers of the center of mass at takeoff.
I have a theory that is more or less related to this topic. In triple jumping, speed conservation depends from ground contact time. I believe that the gct is determined by the time that it takes to the free leg to swing arround the support leg. For example, if you look at jonathan edwards, his free leg is moving forward really fast before and way before ground contact. When his foot touches the ground, his free foot is already (in an horizontal plane) at almost the same level of the support foot and then travels really quickly forwards, allowing him to skip forwards really fast. This is really evident in his best jumps. Jumpers who are less efficient conserving speed clearly hit the ground whith their free legs way back, so that it has to travel forward while the other foot is planted, wasting plenty of time. So, should one emphasize on the free leg instead on the support leg? I find this method to be extremelly successfull in bounding, although one problem that arises is some kind of huge torque on the body when the contact leg doesn´t compensate the swing forces.
I find this really interesting because I have had the best results while long jumping whenever I really focused on “kicking” / “extending” my free leg in front of me.
I asked coach Schexnayder your question about the free leg because it got me to thinking that there may be some validity to the question and his answer was “No, it needs to be behind the other in order to set up the correct timing of the swing leg.“ When teaching triple jump I do emphasize the free leg mechanics much more than the support leg because I believe that if you jump correctly your support leg comes through naturally from the pre-stretch and elastic responses you create while jumping. Hopefully it makes some sense.
Well put, the support leg passing close to the butt is simply a form of feedback. One does not have to create it artifically. Much like backside mechanics in sprinting it can help determine what how much force was applied to the track vertical vs. horizontal. Thanks tkaberna.
totally disagree…the butt kick does not happen naturally for many many many many jumpers that i watch all the time…it isnt something that everyone does when they long jump. But it is a noticable difference between MOST of the very elite guys compared to the average…
Just a quick question. I would think stiffness starts from the ground up through the COM on ground contact. The arch collapses before the ankle moves, the ankle moves before the knee does, and the knee moves before the hip. So why would the hip be active in any role than stabilizing the movement structure?
Co-contraction takes place prior to ground contact to increase stiffness in preparation for impact. This is actually present in walking, jogging, running, sprinting, etc. At best this is a subconscious higher brain driven activity with much neuromodulation taking place without the athlete even being aware of it. It would seem that one could certainly be trained to make these things more efficient by enhancing SSC, eccentric power, neural conduction, lessening contractile thresholds, etc.
By subconscious higher brain driven activity are you possibly referring to spinal driven activity as well. I know some like to keep the brain and spinal cord separate like myself and others think of them as one whole.
I understand that co-contraction and isometric contractions take place prior to GC, but even then all the components of stiffness would require feedback during GC to maintain system stability for the next desired action.
It is in reference to both jumps. My understanding of he backside mechanics in both the triple jump, long jump, and sprints for that matter is that for the majority of cases it is a reflex action. This reflex allows the teacher an opportunity to determine direction of forces applied to the ground. If the athlete pushes vertical hard and fast enough the take off leg will have a propensity to swing much closer to the “butt” ...it is not the other way round. Meaning if an individual has enough flexibility to swing they foot close to the “butt” after take off equates an adequate force application in the desired direction…it may look pretty but it doesn’t work.
Mike in reference to the pull, i am interested in understanding how one effects a pull through the long axis of the torso.
It is in reference to both jumps. My understanding of he backside mechanics in both the triple jump, long jump, and sprints for that matter is that for the majority of cases it is a reflex action. This reflex allows the teacher an opportunity to determine direction of forces applied to the ground. If the athlete pushes vertical hard and fast enough the take off leg will have a propensity to swing much closer to the “butt” ...it is not the other way round. Meaning if an individual has enough flexibility to swing they foot close to the “butt” after take off equates an adequate force application in the desired direction…it may look pretty but it doesn’t work.
I agree with whole-heartedly. I can’t count the number of times people comment on how pretty and efficient someone looks running, jumping, or throwing and only to see that person finish near the bottom because their movements were so slow.
it would be good if this thread was still called Dwight Phillips…hate to say i told you so, but he is a different jumper now compared to 2004. Different coach? age? unlucky? what do you all think…
its amazing, becuase i foul alot…as you all know…and Dwight used to foul ALOT…and i know a coach who lives near me who was coached under Tellez in the 80’s and he keeps telling me that Tellez was a master when it came to not fouling etc…
well, look at Dwight now, he hardly fouls at all anymore (9 straight legal jumps at trials)...BUT, doesnt jump or run the same way either..just crazyness…all these athletes that wins major then switches coaches…
