Are you going back and forth between ROM @ ground contact and total ROM? You’re losing me.
You lost me. Total ROM at the hip was the original reference for each stride and I’ll stand by ROM at the hip getting larger from acceleration to maxV unless you point out proof to the contrary. If such proof comes from European Sources then I’ll still stand by my statement.
When I’m discussing it I’m mostly referring to ROM of the joints during their period of force application and / or the total ROM of the legs through the gait cycle. Having said that though, even by your definition, I don’t think there’s less ROM during acceleration. I’m not aware of any research looking at ROM of hip from acceleration through maxV (although Mann is in year 2 of a study looking at acceleration) but you’d be surprised that the ROM at the hip during sprinting isn’t as great as one might think. In fact, hip extension is less than what’s observed in walking and the better you get the less hip extension takes place. In acceleration, it’s not unusual for the thigh to move to >90 hip flexion which is something that is practically impossible in upright running at top speed.
When I’m discussing it I’m mostly referring to ROM of the joints during their period of force application and / or the total ROM of the legs through the gait cycle. Having said that though, even by your definition, I don’t think there’s less ROM during acceleration. I’m not aware of any research looking at ROM of hip from acceleration through maxV (although Mann is in year 2 of a study looking at acceleration) but you’d be surprised that the ROM at the hip during sprinting isn’t as great as one might think. In fact, hip extension is less than what’s observed in walking and the better you get the less hip extension takes place. In acceleration, it’s not unusual for the thigh to move to >90 hip flexion which is something that is practically impossible in upright running at top speed.
The problem is Mann hasn’t published much of anything unless you go off one of his sessions. Which everyone cannot do.
I no longer stand by my statement. I assume everything else was correct in the statement. Thanks for correcting me, I reran what I thought should happen and you are right.
Are saying that pulling or clawing/pawing is a good thing? At 60m, acceleration is finished or nearly finished for most sprinters. At worst a 6.55s 60m runner just finished his 50-60m split in .87s, he shouldn’t drop below .9s until at least the 80-90m segment and no worse than .93s for the final segment. 6.55 + .87 + .88 + .9 + .93 giving that runner at worst a 10.13s run, while the typical run would be a .85 + .86 + .89 + .89 for 10.03s and the GB guys have a hard time doing what should be done in the worst case scenario. I think Williameson dropped under 10.10s once of all the GB sprinters besides Chambers this season.
Whoops. Just to clarify, clawing/pawing/pulling is probably not a bad thing to incorporate in some sprint drills as long as one focuses on doing it in the traditional braking phase. In actual sprinting maxV it is more like kicking back with an almost extended leg prior to the leg hitting the ground. Too late to try clawing/pawing/pulling in actual sprinting as the time with which reflex activation can react is too small for reflex activation to have much effect. Anyway, this would cause pushing or too much ground contact time.
Look at Dix in the sprint data put forward by Mike earlier, he still (probably)accelerates between 60 and 70-m. Just beyond 60m is where I’ve noticed separation between the winners and the rest so this is an area I think needs more attention for future champions. Again, look at Gatlin and Flo-Jo for the technique. Please, Mero and Komi have provided a lot of foundation for improvements to sprint performance from where the next generation of researchers will show how to improve further. Some sprinters worked it out a long time ago (Gatlin and Flo-Jo) but there is still a long way to go. However too many people take Mero and Komi’s research as the MODEL but you have to realise that it represents sprinters of a certain class and we need to project from that what an ELITE MODEL would look like. As for Bosch, I love the book but explain to me exactly what is elastic strength and reactive strength?
As for ROM, the only thing I recognise is that for really fast top speed, the thigh doesn’t pass perpendicular until the foot is no longer in contact with the ground. I was writing an article explaining some very interesting relationships that may be the cause of fast maximum velocity. If the debate gets heated I might have to rush out a one page outline. And finally, we are a long way from the 10-m test at the moment. Great brainstorming though.
Just so you know, the USATF biomechanist who’s looked at the data of all the American sprint champs over the past 2 decades think Gatlin is one of the most inefficient runners he’s looked at. I tend to think the same. A prime example of improved performance through pharmacology.
Flojo is very good on the other hand. Mann said she’s about the only female who could do what the men could do as far as angular velocities at touchdown.
Just so you know, the USATF biomechanist who’s looked at the data of all the American sprint champs over the past 2 decades think Gatlin is one of the most inefficient runners he’s looked at. I tend to think the same. A prime example of improved performance through pharmacology.
Flojo is very good on the other hand. Mann said she’s about the only female who could do what the men could do as far as angular velocities at touchdown.
Well if the professor thinks so then I may have to stop plugging Gatlin. Perhaps he was only good at one other thing, generation of force with the leg almost fully extended at impact. Who is this Mann man? Best make himself available for us to ask him questions.
Shame there is no biomechanical data and lack of pictures on Flo-Jo.
Are saying that pulling or clawing/pawing is a good thing? At 60m, acceleration is finished or nearly finished for most sprinters. At worst a 6.55s 60m runner just finished his 50-60m split in .87s, he shouldn’t drop below .9s until at least the 80-90m segment and no worse than .93s for the final segment. 6.55 + .87 + .88 + .9 + .93 giving that runner at worst a 10.13s run, while the typical run would be a .85 + .86 + .89 + .89 for 10.03s and the GB guys have a hard time doing what should be done in the worst case scenario. I think Williameson dropped under 10.10s once of all the GB sprinters besides Chambers this season.
Whoops. Just to clarify, clawing/pawing/pulling is probably not a bad thing to incorporate in some sprint drills as long as one focuses on doing it in the traditional braking phase. In actual sprinting maxV it is more like kicking back with an almost extended leg prior to the leg hitting the ground. Too late to try clawing/pawing/pulling in actual sprinting as the time with which reflex activation can react is too small for reflex activation to have much effect. Anyway, this would cause pushing or too much ground contact time.
Look at Dix in the sprint data put forward by Mike earlier, he still (probably)accelerates between 60 and 70-m. Just beyond 60m is where I’ve noticed separation between the winners and the rest so this is an area I think needs more attention for future champions. Again, look at Gatlin and Flo-Jo for the technique. Please, Mero and Komi have provided a lot of foundation for improvements to sprint performance from where the next generation of researchers will show how to improve further. Some sprinters worked it out a long time ago (Gatlin and Flo-Jo) but there is still a long way to go. However too many people take Mero and Komi’s research as the MODEL but you have to realise that it represents sprinters of a certain class and we need to project from that what an ELITE MODEL would look like. As for Bosch, I love the book but explain to me exactly what is elastic strength and reactive strength?
As for ROM, the only thing I recognise is that for really fast top speed, the thigh doesn’t pass perpendicular until the foot is no longer in contact with the ground. I was writing an article explaining some very interesting relationships that may be the cause of fast maximum velocity. If the debate gets heated I might have to rush out a one page outline. And finally, we are a long way from the 10-m test at the moment. Great brainstorming though.
We aren’t that far from the 10m start, Malcolm Arnold likes to test 10m and 30m a lot and it’s his guys we are discussing.
Anyways, a ground contact is .06-.08s, even in non-elite (not even sub-elite) ground contact is still likely to be less than a .1s that’s an awfully short period of time to initiate and stop an action. This is one area Dr. Deadlift and I actually agree upon, we agree on other items to but not much concerning the gait cycle. To cut it back to the braking phase only cuts the time for execution by 40%, even at the spinal level the body doesn’t work that way. It comes down to preparing the body for ground contact and this is done by positioning the limbs which is where almost all of us on this board have diverged from Dr. Deadlift as so evident in one of the classic threads on this board.
The body (spinal level, visiomotor cortex, muscle spindles, golgi tendon organs, and other proprioceptive parts) actually prepares for ground contact quite nicely without any intervention from the brain trying to override the mechanical parameters necessary to stay in motion. What happens during the ground contact phase has already been decided by the momentum present in the system and the ground reaction forces which cause the chain of events for the completion of the stride depending on the positioning of the limbs and the combined elastic, reactive, concentric strength capabilities of those limbs together, but immediately upon impact of the next stride while trying to claw will cause excessive pushing which further extends the leg behind the center line at MaxV causing the leg to flail and extending the moment arm which needs to come back through and when it shortens and does come back forward it cannot come forward as far as possible because the body realizes it will tumble if it doesn’t plant and plants further in front of the body (limb positioning) causing a prolonged braking period and decreases stiffness in the system causing a longer ground contact which ultimately keeps feeding itself in terms of stride rate to minimize speed loss and excessive backside mechanics.
I tend to think guys like Cavagna, McNeil Alexander, and the spring mass guys (Blickhahn,Farley,McMahon, Hegland, and Taylor) have contributed more to the field than Komi or Mero. That’s my personal opinion and the combination of about 40 years developing modeling possibilities that I didn’t see in your paper that I wish you included more of instead of the classic Cavagna and Alexander references. I’ll discuss this in the article thread more clearly, no since in making an argument of it here, especially when I haven’t throughly gone over the article. The Hunter and Di Prampero references are nice though.
Elastic and Reactive Strength in sprinting are forces generated from reactive movements and elastic sources. Elastic strength is the ability for an elastic structure in this case the human leg to store elastic energy and use it and it’s used in a reactive setting as a reaction to ground contact.
Whether we are discussing the average sprinter, the sub-elite sprinter, or the elite sprinter there are certain things which hold true and I believe these are gait specific, but hold true for each gait, sprint, bound, hop, skip, or run. The less steps you take to finish a race the faster your time will be. The less steps you take the smaller your step rate will be. The faster your limbs move in terms of angular velocity the larger the ROM you need. The smaller the changes in jerk (rate of change in acceleration) to zero acceleration the faster you will run. All of these point to enhancing step length and not step rate.
Are saying that pulling or clawing/pawing is a good thing? At 60m, acceleration is finished or nearly finished for most sprinters. At worst a 6.55s 60m runner just finished his 50-60m split in .87s, he shouldn’t drop below .9s until at least the 80-90m segment and no worse than .93s for the final segment. 6.55 + .87 + .88 + .9 + .93 giving that runner at worst a 10.13s run, while the typical run would be a .85 + .86 + .89 + .89 for 10.03s and the GB guys have a hard time doing what should be done in the worst case scenario. I think Williameson dropped under 10.10s once of all the GB sprinters besides Chambers this season.
Whoops. Just to clarify, clawing/pawing/pulling is probably not a bad thing to incorporate in some sprint drills as long as one focuses on doing it in the traditional braking phase. In actual sprinting maxV it is more like kicking back with an almost extended leg prior to the leg hitting the ground. Too late to try clawing/pawing/pulling in actual sprinting as the time with which reflex activation can react is too small for reflex activation to have much effect. Anyway, this would cause pushing or too much ground contact time.
Look at Dix in the sprint data put forward by Mike earlier, he still (probably)accelerates between 60 and 70-m. Just beyond 60m is where I’ve noticed separation between the winners and the rest so this is an area I think needs more attention for future champions. Again, look at Gatlin and Flo-Jo for the technique. Please, Mero and Komi have provided a lot of foundation for improvements to sprint performance from where the next generation of researchers will show how to improve further. Some sprinters worked it out a long time ago (Gatlin and Flo-Jo) but there is still a long way to go. However too many people take Mero and Komi’s research as the MODEL but you have to realise that it represents sprinters of a certain class and we need to project from that what an ELITE MODEL would look like. As for Bosch, I love the book but explain to me exactly what is elastic strength and reactive strength?
As for ROM, the only thing I recognise is that for really fast top speed, the thigh doesn’t pass perpendicular until the foot is no longer in contact with the ground. I was writing an article explaining some very interesting relationships that may be the cause of fast maximum velocity. If the debate gets heated I might have to rush out a one page outline. And finally, we are a long way from the 10-m test at the moment. Great brainstorming though.
We aren’t that far from the 10m start, Malcolm Arnold likes to test 10m and 30m a lot and it’s his guys we are discussing.
Anyways, a ground contact is .06-.08s, even in non-elite (not even sub-elite) ground contact is still likely to be less than a .1s that’s an awfully short period of time to initiate and stop an action. This is one area Dr. Deadlift and I actually agree upon, we agree on other items to but not much concerning the gait cycle. To cut it back to the braking phase only cuts the time for execution by 40%, even at the spinal level the body doesn’t work that way. It comes down to preparing the body for ground contact and this is done by positioning the limbs which is where almost all of us on this board have diverged from Dr. Deadlift as so evident in one of the classic threads on this board.
The body (spinal level, visiomotor cortex, muscle spindles, golgi tendon organs, and other proprioceptive parts) actually prepares for ground contact quite nicely without any intervention from the brain trying to override the mechanical parameters necessary to stay in motion. What happens during the ground contact phase has already been decided by the momentum present in the system and the ground reaction forces which cause the chain of events for the completion of the stride depending on the positioning of the limbs and the combined elastic, reactive, concentric strength capabilities of those limbs together, but immediately upon impact of the next stride while trying to claw will cause excessive pushing which further extends the leg behind the center line at MaxV causing the leg to flail and extending the moment arm which needs to come back through and when it shortens and does come back forward it cannot come forward as far as possible because the body realizes it will tumble if it doesn’t plant and plants further in front of the body (limb positioning) causing a prolonged braking period and decreases stiffness in the system causing a longer ground contact which ultimately keeps feeding itself in terms of stride rate to minimize speed loss and excessive backside mechanics.
I tend to think guys like Cavagna, McNeil Alexander, and the spring mass guys (Blickhahn,Farley,McMahon, Hegland, and Taylor) have contributed more to the field than Komi or Mero. That’s my personal opinion and the combination of about 40 years developing modeling possibilities that I didn’t see in your paper that I wish you included more of instead of the classic Cavagna and Alexander references. I’ll discuss this in the article thread more clearly, no since in making an argument of it here, especially when I haven’t throughly gone over the article. The Hunter and Di Prampero references are nice though.
Elastic and Reactive Strength in sprinting are forces generated from reactive movements and elastic sources. Elastic strength is the ability for an elastic structure in this case the human leg to store elastic energy and use it and it’s used in a reactive setting as a reaction to ground contact.
Whether we are discussing the average sprinter, the sub-elite sprinter, or the elite sprinter there are certain things which hold true and I believe these are gait specific, but hold true for each gait, sprint, bound, hop, skip, or run. The less steps you take to finish a race the faster your time will be. The less steps you take the smaller your step rate will be. The faster your limbs move in terms of angular velocity the larger the ROM you need. The smaller the changes in jerk (rate of change in acceleration) to zero acceleration the faster you will run. All of these point to enhancing step length and not step rate.
Thanks for explaining the clawing/pawing/pulling training method more clearly. Given the short force execution time during ground contact the force/momentum must be built up before contact. I only suggest trying to do clawing/pawing/pulling in the braking phase as a learning step that results from pre-impact.
The spring mass guys (Arampatzis included) will probably get a mention in a future article that relates to detailed analysis of training methods. Speaking of articles, Alexander (1989) found only a weak correlation between stride length and maximum speed of r=0.53. However thigh displacement, which must be related to ROM somehow, correlates with speed in males of r=0.93 and 0.96 in females. I can see your point when it comes to total number of strides because if a sprinter can save one step that equals 0.09 seconds on average.
As for the jerkiness of sprinting, the smoother the acceleration the less ATP will be wasted (i.e. more efficiency) saving precious fuel for longer acceleration.
As for the jerkiness of sprinting, the smoother the acceleration the less ATP will be wasted (i.e. more efficiency) saving precious fuel for longer acceleration.
This is what is not studied enough. Maybe it’s self-evident, but I tend to think no one wants to think in meters per second cubed.
Speaking of sprint testing sprint performance and training thereof, I found an article written by Valerie Borzov explaining all the above over different tests. I forward it to Mike in case he wants to add it.
As for the jerkiness of sprinting, the smoother the acceleration the less ATP will be wasted (i.e. more efficiency) saving precious fuel for longer acceleration.
This is what is not studied enough. Maybe it’s self-evident, but I tend to think no one wants to think in meters per second cubed.
Agreed.Difficult as that would be I would much rather work with that than with spring mass constants, vibration, harmonic frequency etc as per the spring mass guys. That can be your gig.
As for the jerkiness of sprinting, the smoother the acceleration the less ATP will be wasted (i.e. more efficiency) saving precious fuel for longer acceleration.
This is what is not studied enough. Maybe it’s self-evident, but I tend to think no one wants to think in meters per second cubed.
Agreed.Difficult as that would be I would much rather work with that than with spring mass constants, vibration, harmonic frequency etc as per the spring mass guys. That can be your gig.
If you can measure time and distance then you can measure Jerk. If you have a known mass then you can measure Yank too.
I believe Jerk does a good job of explaining why 10m start times are not as effective in predicting 100m times.
The spring-mass model of running allows for the body to have adjustable springs.
There some jumps related stuff related to reactive/elastic strength by David Kerin floating around the web. You used to be able to get the article here, but it’s still available at the gill athletics site.
Well if the professor thinks so then I may have to stop plugging Gatlin. Perhaps he was only good at one other thing, generation of force with the leg almost fully extended at impact. Who is this Mann man? Best make himself available for us to ask him questions.
Dr. Ralph Mann, Silver medal in 72 Olympics in 400m Hurdles and the USATF biomechanist for the sprint events. He’s not published his data (at least not in peer-reviewed journals) for about 20 years but it is available.
Gatlin’s major flaw was that he made contact too far in front of his COM.
Shame there is no biomechanical data and lack of pictures on Flo-Jo.
Mann has plenty. On an interesting note, he told me that she was an elite technical model before she was the 10.58 100m queen that we know her today. He said in 88 (when she ran like she had a rocket on her back) her mechanics didn’t significantly change but her power output did.
Anyways, a ground contact is .06-.08s, even in non-elite (not even sub-elite) ground contact is still likely to be less than a .1s that’s an awfully short period of time to initiate and stop an action.
While the point is well taken, ground contacts are never as short as 0.06. I believe the elite of the elite are around 0.8 and national class are around 0.85 with sub elites being around 0.9-0.1s.
The body (spinal level, visiomotor cortex, muscle spindles, golgi tendon organs, and other proprioceptive parts) actually prepares for ground contact quite nicely without any intervention from the brain trying to override the mechanical parameters necessary to stay in motion. What happens during the ground contact phase has already been decided by the momentum present in the system and the ground reaction forces which cause the chain of events for the completion of the stride depending on the positioning of the limbs and the combined elastic, reactive, concentric strength capabilities of those limbs together, but immediately upon impact of the next stride while trying to claw will cause excessive pushing which further extends the leg behind the center line at MaxV causing the leg to flail and extending the moment arm which needs to come back through and when it shortens and does come back forward it cannot come forward as far as possible because the body realizes it will tumble if it doesn’t plant and plants further in front of the body (limb positioning) causing a prolonged braking period and decreases stiffness in the system causing a longer ground contact which ultimately keeps feeding itself in terms of stride rate to minimize speed loss and excessive backside mechanics.
Good explanation!
Whether we are discussing the average sprinter, the sub-elite sprinter, or the elite sprinter there are certain things which hold true and I believe these are gait specific, but hold true for each gait, sprint, bound, hop, skip, or run. The less steps you take to finish a race the faster your time will be. The less steps you take the smaller your step rate will be. The faster your limbs move in terms of angular velocity the larger the ROM you need. The smaller the changes in jerk (rate of change in acceleration) to zero acceleration the faster you will run. All of these point to enhancing step length and not step rate.
I agree with 99% of what you said here but I think I’d add the caveat that you have to be doing an intra-athlete comparison and it won’t necessarily work comparing one athlete to another. For example, if you took a 9.77 by Powell, Gay, Greene, and Bolt, they’d likely all have differences in touchdowns over the course of the race with Bolt obviously having the fewest. A lot of the variability is simply due to their acceleration mechanics though so I suspect it might be more relevant to look at strides taken from 50m-100m. I would guess that this would more closely correlate with 100m performance.
would look like. As for Bosch, I love the book but explain to me exactly what is elastic strength and reactive strength?
