Thickness of Stepanov's shoe?

[Suso2]

As you all know, in 1957 Yuri Stepanov jumped 2.16 m (7'1") and broke the world record in the high jump. Shortly afterward it was noticed that he had used a built-up takeoff shoe (which was legal by the IAAF rule book at that time --nobody had realized until then that there was this loophole in the rules!) Soon other athletes (Russians, but also Swedes and probably others) started using built-up shoes, and finally the IAAF set a limit on the allowable thickness of the takeoff shoe: 13 mm. This is the rule that we still have today.

For a long time, I thought that in 1957 the Russians had worn a single type of built-up shoe, maybe 30 mm thick (that was just a wild guess on my part, or maybe I saw this number quoted somewhere). But then someone told me about 10 or 15 years ago that his recollecton was that the 13 mm build-up that was finally adopted by the IAAF was actually the build-up that Stepanov had used in his 2.16 m world record jump, and that this was the reason why the IAAF had adopted that particular thickness. I don't know if this is true, but if it is it would put the Stepanov jump in a new light in relation to marks made after 1957: It would be "legal" by today's rules. But I don't know if Stepanov's shoe was actually 13 mm thick. And somehow, I doubt that it was. My reasoning is that 1/2 inch is a nice round number that an American (or Brit Commonwealth type) would come up with, but 13 mm is a very weird number from a metric standpoint, so it would have been a strange coincidence that the Russians had come up accidentally with a metric thickness that just happened to equal a nice round number in the Imperial system. The alternative is a more likely scenario, that the IAAF came up with a nice, round Imperial measure (1/2 inch, which translates to 12.7 mm) that had nothing to do with whatever thickness Stepanov used, and then implemented this in the rulebook as the nearest metric value to that: 13 mm. This is the common practice in most other track measures: an Imperial number that gets rounded off to a metric value, and the metric value then becomes the official one. [For example, the minimum legal weight for the men's shot is 7.26 kg (rounded off upward from (16 lb * 0.4536 kg/lb =) 7.2576 kg. So a shot weighing 7.259 kg would be slightly heavier than 16 lb, but would be illegal for a world record.]

There may be a way to answer this question. Soon after the Stepanov record, Track & Field News showed on its cover a picture of Stepanov jumping, and the takeoff shoe seems to be clearly visible in the photo. Unfortunately, the only copy I have available of this photo is a very low resolution version that was posted about a year ago at this TFN website. If Garry could show us a full-size version of that picture, it might be possible to make a reasonably good estimate of the thickness of Stepanov's shoe.

Can anyone else shed more light into this question?

[dukehjsteve]

I have the 8/57 issue in front of me now.... photo is indeed on the front page. But you can't tell a thing from it. The caption also says the photo was taken in a practice session.

[Suso2]

Hmmm, not very encouraging.

I assume that you realize that Stepanov was a straddle "lefty", so we need to look at his RIGHT shoe. (Believe me, I am not trying to insult your intelligence! ... but in today's flop era I think many people probably could not tell from a photo of a straddle bar clearance if the athlete had taken off from the left or right foot.)

[dukehjsteve]

Hmmm, not very encouraging.

I assume that you realize that Stepanov was a straddle "lefty", so we need to look at his RIGHT shoe. (Believe me, I am not trying to insult your intelligence! ... but in today's flop era I think many people probably could not tell from a photo of a straddle bar clearance if the athlete had taken off from the left or right foot.)

You're talking to a HJ'er here suso ! No, the pic is not real distinct of either shoe.

[gh]

IAAF Record Progression book says the lift was 3-5cm.

[Per Andersen]

I find it hard to believe that the thickness of the sole on Stepanov's right shoe was only 13 mm. All I heard at that time was 4-5cm. The thickness of the sole caused some of these jumpers to adopt a limping gait in the run-up.

In the Stepanov picture Steve is referring to the left shoe might not have been a spiked shoe at all. The take-off shoe clearly has spikes and the front of the sole appears to be much thicker.

[lonewolf]

Do I remember correctly that circa 1950 some HJ takeoff foot shoes had a "rocker" built up across the ball of the foot.?

[jhc68]

When did heel spikes first appear on HJ shoes?

[decathlete73]

spikes on heels of HJ jump shoes

The first spiked shoes with heel spikes date back to 1880's . They were used for jumping and throwing.

[decathlete73]

Russian HJ shoes What MFG were they?

Russia had there own make of track and field spikes. Anyone no make?

[Cooter Brown]

The thickness of the sole caused some of these jumpers to adopt a limping gait in the run-up.

Seems like the thicker sole would be more of a hindrance.

[Suso2]

Cooter:

The unevenness of the shoe thickness produces advantages and disadvantages, but overall it produces a net advantage. A disadvantage is that the unevenness would prevent you from running at an extremely high speed (such as a sprinter's or a long jumper's for example, who go at 11 or 12 meters/second). But high jumpers go at relatively slow speeds (the fastest go at slightly over 8 m/s, and most high jumpers don't even go that fast). These (sub-maximum) speeds are attainable even when wearing uneven shoes.

There are two advantages to wearing a thick-soled takeoff shoe and a thin non-takeoff shoe.

Advantage #1. One advantage is the larger vertical range of motion that the center of mass has available during the takeoff phase. This helps the athlete to produce a larger impulse, and therefore a higher jump.

Advantage #2. The second advantage is that at the end of the takeoff your c.m. is (obviously) at a higher height than if you had worn a thinner-soled shoe.

Situation "a". If you wore two ultra-thin shoes, you would be able to jump a certain height.

Situation "b". If you wore two shoes such that both had, say, 3 cm of thickness, you would jump 3 cm higher (because of advantage #2).

Situation "c". If you wore a takeoff shoe with 3 cm of thickness and a non-takeoff shoe with zero cm of thickness, you would jump 3 cm higher than in situation "a" due to advantage #2, but you would also jump an extra amount higher due to advantage #1. This is because you would be lower than in Situation "b" at the start of the takeoff phase, when your takeoff foot first touches the ground. (Sorry, but the amount of extra height produced by advantage #1 can't be calculated accurately without making a whole bunch of inadmissible assumptions; we just know that there is an advantage, we don't know how big it is.) But let's say, for the sake of argument, that advantage #1 would be 2 cm. That would make the total advantage be 5 cm. (Remember that this is all an example, don't believe these numbers.)

OK, we now need to make a little adjustment to the explanation that I just made for Situation "c". The uneven shoes will affect slightly your capacity for running fast in the run-up. This produces a slight negative effect. Alright, so in Situation "c" this makes advantage #2 be a little bit less than 3 cm, and advantage #1 a little bit less than what it would have been if (miraculously) the unevenness of the shoes had not affected the athlete's running speed. So let's say that advantage #1 would have been 2.9 cm, and advantage #1 would have been 1.9 cm (no, I don't know what these new values would have been; the point here is to realize that the actual advantages would be slightly smaller than if the run-up had not been affected). But still, the uneven shoes would produce a net advantage of (2.9+1.9=) 4.8 cm. This is 4.8 cm better than Situation "a" and 1.8 cm better than Situation "b".

Let's say now that you decided to wear a takeoff shoe with a 40 cm sole (that would be a ridiculous 16-inch sole!) and a thin non-takeoff shoe. Effects "1" and "2" would be improved, but your run-up would be a real mess, so overall the height of your jump would actually be worse than if you wore the two thin shoes of Situation "a".

The point of this whole discussion is to point out that there is a certain optimum thickness of the takeoff shoe. Too thin is bad, but too thick is bad too. We don't know what this optimum thickness is, but practical experience (Stepanov for example!) indicates that the optimum is definitely thicker than the 13 mm currently set as the maximum allowed by the IAAF.

[Suso2]

Good news!

dukehjsteve sent me a very good scan of Stepanov's photo. Using the length of Stepanov's left foot in the picture, I estimated a scale factor, and from that I calculated an approximate value for the thickness of Stepanov's right (i.e., takeoff) shoe. (See http://home.comcast.net/~dapena/shoes.jpg )

The thickness of the shoe comes out to 25 mm. Given that I don't know exactly how far off the left shoe (which I used to get my scale factor) was from the plane of the photo, that I don't know exactly the real-life length of Stepanov's left shoe, and that I can't see with perfect accuracy the edge of the built-up part of the takeoff shoe, we should not consider 25 mm to be an exact value by any means. But, being ultra conservative, we can definitely say that the thickness was somewhere between 20 and 30 mm.

[Per Andersen]

I guess even Dumas with his super slow run-up could not have handled a 40cm sole

The 4.8cm advantage makes sense if we look at Stepanov's best with a 13mm sole in 1958, the 2.12 in the dual meet against the Americans in Moscow.
By then the 13mm rule was in effect and the shoe was inspected by the Americans. That was the closest Stepanov ever came to the 2.16 with a regular shoe and by 1959 he was gone.

I suppose a built up shoe would be impossible with a curved flop run-up. It would have required a slower, minimum curved run which would have been pointless.

Well, maybe Manson at his slow no-curve run stage of a few years ago years ago could have given it a go.

Suso2, you should definitely post more often. What about a short analysis of what Silnov is doing with his technique?

[Per Andersen]

Good news!

dukehjsteve sent me a very good scan of Stepanov's photo. Using the length of Stepanov's left foot in the picture, I estimated a scale factor, and from that I calculated an approximate value for the thickness of Stepanov's right (i.e., takeoff) shoe. (See http://home.comcast.net/~dapena/shoes.jpg )

The thickness of the shoe comes out to 25 mm. Given that I don't know exactly how far off the left shoe (which I used to get my scale factor) was from the plane of the photo, that I don't know exactly the real-life length of Stepanov's left shoe, and that I can't see with perfect accuracy the edge of the built-up part of the takeoff shoe, we should not consider 25 mm to be an exact value by any means. But, being ultra conservative, we can definitely say that the thickness was somewhere between 20 and 30 mm.

Thanks!! I did not see this post when I posted a few minutes ago. I actually thought you were Dapena No kiddinng! Also thanks to Steve. I have been wondering about the sole of that shoe for for many, many years.