Sprinting Mechanics

    Posted In: Sprints

        • Participant
          delldell on August 21, 2003 at 9:13 pm #8540

          Anyway, I know sprinting mechanics get get very very complicated, so I just have a few questions about the basics if you all don't mind.

          Simply, could you explain these terms/concepts:

          Horizontal vs Vertical forces-
          COG-
          Dorsiflexion-
          Arm swing-how far back or don't even worry and let it be natural?
          Knee height- No higher than waist or don't even think about it?
          How far and high does your foot go back? Under hips, etc.

          When I was trying some sprinting I tried out different techniques and I just want to make sure I don't pick up any bad habits. Sometimes it felt like my feet were on the ground too long or like they were stomping. Sometimes it would be like my knees were moving up and down quickly but I didn't feel like I was going forward very fast.
          I also found this site, and wanted to see what you all thought of the advice.

          https://www.advantageathletics.com/sprints/sprinting_form.html

          https://www.advantageathletics.com/sprints/

          EDIT: Phoenix's site gave me some insight: https://www.regenerationlab.com/archives/000054.php#000054

          I never wanted to think too much about my running form, but I feel like there is something wrong with my form that's holding me back. I don't know whether it's my knees going too high and straight up or my legs not coming back far enough. If anyone has any general guidelines, that'd help. Sorry if this sounds really stupid.

        • Keymaster
          Mike Young on August 23, 2003 at 12:28 pm #21831

          I think that all those links are pretty good and the AA links give some decent advice although if I wanted to really pick nits there are a couple things I disagree with. I do however agree with Carl's assessment that many individuals pick up bad running habits through attempts to actually improve their mechanics. Most mechanical problems can be fixed with correct training (rather than actually overhauling mechanics) but I think it would be naive to think that everyone naturally has their ideal mechanics. This is especially true of lower level runners and it baffles me when people (not referring to Carl as I???m sure he probably agrees) use animal references about animals naturally being able to run fast without any worries about their mechanics. Apparently it never occurred to these people that in nature, the ostrich that runs at the equivalent of a 14.5 second 100m would soon be eaten and then obviously never have to worry about being slow ever again. A human running that fast (or slow perhaps?) is probably doing so because they may be weak, uncoordinated, ungainly, overweight, inflexible, awkward, or have never had opportunities to develop the motor patterns that govern locomotion. Regarding this last point, I'm sure we all know people who are so ungainly, inactive, or uncoordinated that they even look awkward walking, much less running. Fortunately, these people don't have to worry about being devoured like their ostrich counterparts but these same people are the ones who must often work to improve sprinting mechanics due to problems with poor coordination, flexibility issues, or lack of activity.

          Having said all that, I think the most important mechanical point of sprinting is to make foot contact as close to under the COM as possible with a shank angle that is almost perpendicular to the ground. All other points should pretty much be aimed towards achieving this goal.

          ELITETRACK Founder

        • Member
          400stud on August 23, 2003 at 12:45 pm #21832

          What's a shank angle?

        • Keymaster
          Mike Young on August 23, 2003 at 1:08 pm #21833

          The shank angle is that of the tibia / lower leg with respect to the ground.

          ELITETRACK Founder

        • Keymaster
          Mike Young on August 23, 2003 at 1:09 pm #21834

          Also, my above comments were obviously (I hope) for steady state or maxV running and NOT acceleration.

          ELITETRACK Founder

        • Participant
          delldell on August 25, 2003 at 10:22 am #21835

          [i]Originally posted by mike[/i]

          Having said all that, I think the most important mechanical point of sprinting is to make foot contact as close to under the COM as possible with a shank angle that is almost perpendicular to the ground. All other points should pretty much be aimed towards achieving this goal.

          Could you give a visual example of this if possible. Thanks.

        • Keymaster
          Mike Young on August 25, 2003 at 1:05 pm #21836

          ELITETRACK Founder

        • Keymaster
          Mike Young on August 25, 2003 at 1:07 pm #21837

          Guess which one runs faster 😀

          ELITETRACK Founder

        • Member
          2belite on August 25, 2003 at 1:42 pm #21838

          Its a nice illustration of commensurate joint angles.

        • Participant
          delldell on August 25, 2003 at 9:50 pm #21839

          Thank you very much. Could you also show how high knees should be up(1) and how far and out the back leg should be(2). Preferably for a taller, lankier runner.

          That would help me out alot.

        • Member
          400stud on August 26, 2003 at 12:39 am #21840

          https://www.advantageathletics.com/sprints/bruno.html

          I think he has good form. Powerful stride, good arm action, optimal knee height achieved. A very good runner. It's only ashame his time at UCLA has been detrimental to him.

        • Member
          2belite on August 26, 2003 at 2:11 am #21841

          That's a poor example good sprint mechanics. Mike posted a pic above that shows a sprinter with bad mechanics, an acute tibia angle at touchdown. Well the opposite of that error, is having an obtuse tibia angle at touchdown( like the guy in 400stud'd link https://www.advantageathletics.com/sprints/bruno.html )

        • Member
          400stud on August 26, 2003 at 4:32 am #21842

          So who's is good and who's is bad because now I'm confused?

        • Keymaster
          Mike Young on August 26, 2003 at 11:06 am #21843

          The picture of Marion I posted above is very close to ideal. Deviations from that shin angle, whether they are acute (foot contact behind the knee as in the right hand picture above) or obtuse (foot contact in front of the knee as in the picture sequence of Bruno), are mechanical problems.

          ELITETRACK Founder

        • Member
          400stud on August 26, 2003 at 11:16 am #21844

          Really? I though Bruno had pretty nice form. He has a powerful stride which probably attributes in some way to his forward swing of his inferior leg ligaments as compared to someone like Marion who plants directly underneath her COM which can be good, but it looks like she has a habit of getting flat-footed at times. Allyson Felix runs pretty similar to Marion herself.

          But what about Kelli White? How do you rate her form?

        • Keymaster
          Mike Young on August 26, 2003 at 7:51 pm #21845

          Kelli White seems ok but I've only seen her run 2x and both were from a distance. Hopefully, if time permits, I'll be able to check out some track on TV.

          As for Bruno, his previously mentioned problem has a compounding negative effect. That is, because his shin angle is so obtuse at ground contact, the horizontal distance between ground contact and the plumb line of his COM is greater than it should be which creates bigger breaking forces.

          To put a video online, you can either add it as an attachment to your post. If that doesn't work, and it isn't too large, I can temporarily host it on the site.

          ELITETRACK Founder

        • Participant
          delldell on August 26, 2003 at 10:02 pm #21846

          So what about knee height and the back leg. The back legs of both those pictures look the same, so is that optimal? Under hip height, how far out, etc? I understand it's natural, but I just wanted some general guidelines. Thanks for the insight.

        • Member
          400stud on August 27, 2003 at 12:35 am #21847

          [i]Originally posted by mike[/i]
          Kelli White seems ok but I've only seen her run 2x and both were from a distance. Hopefully, if time permits, I'll be able to check out some track on TV.

          As for Bruno, his previously mentioned problem has a compounding negative effect. That is, because his shin angle is so obtuse at ground contact, the horizontal distance between ground contact and the plumb line of his COM is greater than it should be which creates bigger breaking forces.

          To put a video online, you can either add it as an attachment to your post. If that doesn't work, and it isn't too large, I can temporarily host it on the site.

          Kelli does have almost a man's form which is why she runs so fast.

          The only problem I saw with Bruno is that he lands too far in front of his COM. Other than that, isn't his knee height/hip height optimal? And like delldell asked, how about his back leg?

        • Member
          2belite on August 27, 2003 at 1:21 am #21848

          [i]Originally posted by delldell[/i]
          So what about knee height and the back leg. The back legs of both those pictures look the same, so is that optimal? Under hip height, how far out, etc? I understand it's natural, but I just wanted some general guidelines. Thanks for the insight.

          Are you asking as a coach or an athlete?

        • Member
          400stud on August 27, 2003 at 1:29 am #21849

          I'll say as an athlete for myself.

        • Keymaster
          Mike Young on August 27, 2003 at 7:17 am #21850

          [i]Originally posted by 400Stud[/i]
          The only problem I saw with Bruno is that he lands too far in front of his COM. Other than that, isn't his knee height/hip height optimal? And like delldell asked, how about his back leg?

          This is a MAJOR problem. So much so that I probably should have stated earlier that all movements should be geared towards setting up a shin angle that is perpendicular to the ground at ground contact AND minimizing the horizontal distance between the point of ground contact and the plumb line of the athlete's COM. All of Bruno's other "great" traits are of little consequence if they don't result in hitting these key points…..at least in my opinion. There are some benefits to the other points you mentioned but I think they are almost inconsequential if they do not help to set up the two previously mentioned points at ground contact. I think if these two points are acheived it will take care of or make insignificant almost every other technical flaw.

          ELITETRACK Founder

        • Keymaster
          Mike Young on August 27, 2003 at 7:20 am #21851

          To put video on your computer, you can use a usb or firewire cable to connect a digital video camera to your computer. If you are still using an analog camera (VHS, Beta, mini-VHS, etc.) you'll need a special video card and video input on your computer.

          ELITETRACK Founder

        • Member
          2belite on August 27, 2003 at 9:51 am #21852

          [i]Originally posted by delldell[/i]
          So what about knee height and the back leg. The back legs of both those pictures look the same, so is that optimal? Under hip height, how far out, etc? I understand it's natural, but I just wanted some general guidelines. Thanks for the insight.

          Knee lift: never parallel or higher, high enough to allow the foot to pass close to or above the opposite knee.
          Back Leg (butt kick) : the foot should reach its highest point when under the butt. If your foot is higher at any point before it reaches under the butt, you have too much backside mechanics.

        • Keymaster
          Mike Young on August 27, 2003 at 9:55 am #21853

          2belite and others-
          I'd be interested to hear your thoughts on my comments regarding sprint mechanics.

          ELITETRACK Founder

        • Member
          400stud on August 27, 2003 at 10:09 am #21854

          Not to sound like an idiot, but why don't you put down all your points in one thread to make it easier and I will comment then.

        • Member
          2belite on August 27, 2003 at 11:22 am #21855

          [i]Originally posted by mike[/i]
          2belite and others-
          I'd be interested to hear your thoughts on my comments regarding sprint mechanics.

          "This is a MAJOR problem. So much so that I probably should have stated earlier that all movements should be geared towards setting up a shin angle that is perpendicular to the ground at ground contact AND minimizing the horizontal distance between the point of ground contact and the plumb line of the athlete's COM. All of Bruno's other "great" traits are of little consequence if they don't result in hitting these key points…..at least in my opinion. There are some benefits to the other points you mentioned but I think they are almost inconsequential if they do not help to set up the two previously mentioned points at ground contact. I think if these two points are acheived it will take care of or make insignificant almost every other technical flaw."(Mike)

          I think the above is dead on. This is why I said on another thread that Coby is no worse off than other sprinters. Get the hips up and most things will sort themselves out.
          However, I do think sprinting is much of a skill as it is dependent on power. I am not sure about this as yet, but I think a big part of "the skill" has to do with takeoff angles.(The angle is from toe-off to the COM, no regards for full extension).

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