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Asics "Space Trustic System"

Discussion in 'Biomechanics, Sports and Foot orthoses' started by User7, Oct 10, 2006.

  1. User7

    User7 Active Member

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    I am interested to know if there is any publically available research basis for Asics "Space Trustic" midsole designs.

    Here's a link to their site with a description of the technology/gimmickry used in their high-end running shoe line:


    The description emphasizes windlass function, but this seems to be much less important in running compared to walking. I wonder if what they're really after is unobstructed plantar fascial elastic recoil.
  2. Craig Payne

    Craig Payne Moderator

    Our research has shown that the "Space Trustic System" does alter plantar pressure patterns in the direction that could be assumed to be due to better windlass function compared to a similar shoe without the system (assuming that the pressure pattern changes seen are considered positive).
    Discussed here:
  3. Even though I believe my good friend Simon Bartold is behind the design of this shoe, I am not certain just how much the windlass effect, as originally described by John Hicks over 50 years ago plays in running mechanics (Hicks JH: The mechanics of the foot. II. The plantar aponeurosis and the arch. J Anatomy. 88:24-31, 1954). Halllux dorsiflexion is probably less of a factor in running than in walking, but I can only state this from a clinical basis since I don't know of any research that has confirmed this.

    Some of the best evidence for the function of the plantar fascia during running comes from experimental research performed by Ker et al nearly 20 years ago where they sectioned the plantar fascia and plantar ligaments sequentially in a cadaver foot loaded in a machine that could measure load and deformation of the longitudinal arch of the foot. They found that the plantar fascia (and other plantar ligaments) added significant stiffness to the arch of the foot (i.e. the plantar fascia and plantar ligaments caused the longitudinal arch to deform less with a given vertical loading force than when they were sequentially sectioned). Since a stiffer longitudinal arch can give more energy return during the vertical oscillations of the center of mass over the running foot, then Ker et al estimated that the plantar fascia and other plantar ligaments contribute 17 Joules (J) of energy out of a total of 100 J of energy with each running step (Ker RF, Bennett MB, Bibby SR, Kester RC, Alexander RMcN: The spring in the arch of the human foot. Nature, 325: 147-149, 1987). In other words, approximately 17% of the "spring energy" in the foot comes from the plantar fascia and plantar ligaments.

    Below is a drawing that I made for my lecture on "The Ten Biomechanical Functions of the Plantar Fascia" that demonstrates the experimental setup of Ker et al. This is a great paper for anyone who wants to transition out of the old world of podiatric biomechanics, hypermobility, and structural deformities and into the new world of stiffness, load vs deformation, and biomechanics that uses more precise scientific terminology.

    Attached Files:

  4. toomoon

    toomoon Well-Known Member

    I must say, I have never seen you use that graphic in any lecture Kevin, but it is scarily like the cadaver model we set up to look at responses to loading. I set a fresh foot and leg in a special jig and loaded the specimen to 900N, to investigate motion at the rearfoot and midfoot. I then sectioned the plantar fascia sequentially to see what happened. The most interesting thing was that with a fully intact PF, the most relevant motion was at the talonavicular and calcanecuboid joints, with not a whole lot happening at the STJ. If there is any interest in this, I will post it on the arena for comment.
    Back to the issue of Space tusstic, and I think User 7 has probably got it pretty much sussed in that I believe the space trusstic works by allowing free storage and return of elastic energy rather than the windlass mechanism per se. Unfortunately, as is the case with all commercial enterprises, once the spin docs get hold of it, the science goes out the window! however, I do feel for them, because the design protocol is very sophisticated, and how do you explain that to the consumer... or even retail.
    Alas, the research is not yet freely available, although I believe it will be, which would be good, because it is extensive.
    The concept is that an the midsole is allow to deform in a controlled manner to allow the MLA structures to distend into the "space' and thus function efficiently and store mechanical energy, which can then be returned during propulsion. Shoe design currently focusses around very rigid and stiff platforms, often with highly inflexible midfoot platforms which severely impede this function... amongst many other things. I do not think it is a gimmick.. in fact from the mathematical modelling at least.. we know it works.
    I feel a little inadequate with this explanation, because commercial enterprise and scientific curiosity are a bad match, but maybe this is the start of a worthwhile discussion. Would be great to get onto the evolution of space trusstic.. which is gender specific midsole design... adaptive to the menstual cycle and the temporary soft tissue changes occuring at week 3!!
  5. LCBL

    LCBL Active Member

    Very interesting point Simon. I know you have been involved in some work in relation to female runners and knee function due to the menstrual cycle. (If its Simon B talking here)

    Slightly off topic - In your work have you come across any evidence for altering a female runners training schedule due to these changes?
  6. Phil Wells

    Phil Wells Active Member


    I would be very interested in seeing the data/output of your cadaver model. Of particular interest is the impact of pf integrity on tarsal motion.


  7. Simon,

    I guess you didn't attend my lecture on "Ten Biomechanical Functions of the Plantar Fascia" in Melbourne at last year's Australian Conference of Science and Medicine in Sport. The graphic I made of Ker et al's experimental setup was used in that lecture to discuss the elastic function of the plantar fascia along with a discussion of the results from Wright and Rennels' paper (Wright DG, Rennels DC: A study of the elastic properties of plantar fascia. U.C. Berkeley Biomechanics Laboratory, Technical memorandum, October 1961) and Ker et al's paper (Ker RF, Bennett MB, Bibby SR, Kester RC, Alexander RM: The spring in the arch of the human foot. Nature, 325: 147-149, 1987). Both are excellent research papers on the elastic nature of the plantar fascia. The main problem I see with the experimental setup used by Ker et al is that the Achilles tendon wasn't loaded. Did you load the Achilles tendon of the specimen you tested? It would be good to see the data from your project...please post it since I'm sure many others would also find it of interest.

    I have a few problems with the idea that the plantar fascia can't function elastically without it being allowed to deform plantarly into a gap into a shoe midsole or orthosis plate. [By the way, can you stretch a rubber band around the corner of table and still shoot it, thereby demonstrating that it doesn't lose it's elastic function by being deformed around an object??] I can see where it might be less likely to be irritated by the type of shoe design you mention, but I doubt that supporting the plantar fascia plantarly diminishes the ability of the foot to store elastic energy significantly. If supporting or "pressing on the plantar fascia" did inhibit the elastic nature of the plantar fascia then all foot orthoses that conformed well to the medial longitudinal arch would prevent the plantar fascia from functioning elastically.

    Playing devil's advocate (a role I just hate to play ;) ), the argument could be made that a lack of support in this area by the shoe could diminish the medial arch support function of the shoe cause pronation-related symptoms to occur in many feet. As you know, this was the case of Dananberg's Kinetic Wedge that was put into some of the Brooks shoes but that caused some runners to develop pronation-related injuries from the decreased midsole durometer plantar to the first metatarsal head. And then Nike had the Tailwind that was supposed to, according to Nike's ads, eliminate all shock-related problems from running but caused so many pronation-related problems that it was discontinued early. Benno Nigg also predicted (and wanted to bet me on this) that his Adidas forefoot plate design in sprinting spikes would result in a new Olympic sprinting record. NOT!! The list goes on, as you know probably more well than I do. As you said earlier "commercial enterprise and scientific curiosity are a bad match" as we have also seen is the case with "research" being conducted by some foot orthosis labs currently.

    Interesting discussion.
    Last edited: Oct 17, 2006
  8. Moreover, with their resemblance to a "leaf spring" and given a suitable material, why wouldn't orthoses or close fitting midsoles enhance elastic energy storeage and return? This would seem more beneficial since the energy dissipated to the orthoses effectively offloads the tissue.
  9. Simon,

    Would be great if you could explain how an inert object such as a running shoe adapts at week 3 ?????????
  10. toomoon

    toomoon Well-Known Member

    Indeed it is Simon B. here Simon.. nice to hear from you, and a very interesting question you pose. The only answer i can give you is anecdotal, however from a personal and very reliable source. It relates to the Australian Women's Hockey team, the Hockeyroos. This team enjoyed unprecedented suceess on the world stage throughout the mid 90's to quite recent times. One of the overriding reasons for their success was an extraordinarily low rate of musculoskeletal injury... documented as way lower than any other team, and far below the statistical averages. The strong word is that this was probably because the whole team was required to be on the oral contraceptive pill, which of course gave linear oestragen levels over the 28 day cycle. Lack of an oestragen "spike' means the window of risk of musculotendinous injury secondary to oestragens' roles as a soft tissue relaxant and CNS stimulant, may have been dramatically reduced. The other interesting thing is that at this time, the coach of the team was a medical doctor... it seems fairly clear he was able to recognise the value of the OCP other than to stop unwanted pregnancy!!
  11. Simon

    I am interested in incorporating this into some research, can you provide details of how these soft tissue changes were manifest and measured in the foot?

    Many thanks.
  12. Craig Payne

    Craig Payne Moderator

    I involved in project in which we doing just that. We have two groups of female runners (pill users and non-users) who are bld testing regularly during cycle and a whole battery of tests are being done at two stages during the cycle.
    Among others we measuring:
    * arch height changes
    * first MPJ dorsiflexion stiffness (ie windlass)
    * ankle joint stiffness
    * global lower limb stiffness
    * perturbation tests
    * function as measured by Pedar.
    Last edited by a moderator: Oct 21, 2006
  13. toomoon

    toomoon Well-Known Member

    Simon.. Craig and I are both involved in the study he mentions, and we should have something to report early next year.. it is a very, very interesting study, and hopefully will answer some important questions. Meantime, I have a heap of pdf files on this topic. if you would like to give me your personal email address, I will mail them to you. My email is sbartold@internode.on.net
    Simon B
  14. Just wondering if the above study that Craig and Simon were working on has been published?
    Would be an interesting read.
  15. Craig Payne

    Craig Payne Moderator

    Hot off the press is the first publication from the study:
    Adam L. Bryant, Ross A. Clark, Simon Bartold, Aron Murphy, Kim L. Bennell, Erik Hohmann, Sonya Marshall-Gradisnik, Craig Payne, and Kay M. Crossley: Effects of estrogen on the mechanical behavior of the human Achilles tendon in vivo. J Appl Physiol, Oct 2008; 105: 1035 - 1043.
  16. User7

    User7 Active Member

    This is an old thread, but Simon Bartold mentioned early in it that the research on plantar fascia energy return they did for the "Space Trustic" system would become publicly available at some point.

    Has anyone see it?

    Also, what are the running shoe companies up to with the shapes they mold their midsoles into?

    For example, the Asics Space Trustic system apparently allowed the plantar midfoot to depress, allowing the PF to function with minimal pressure from the midsole.

    Conversely, Mizuno runners tend to have a horizontal shelf from heel proximal all the way under the base of the 5th met and then slope down from there. (A bit like a traditional heeled office shoe in profile.)

    Many Nike runners have a heel pocket and then the midsole slopes up under the cuboid and 5th met base, and then ramps down to the forefoot (a bit like the contours of a casted orthotic). Even their Free line has this contour, especially the less "minimalistic" 5.0 and 7.0 models. I recall that Nike's running gait studies upon which the Free line was based found higher pressures under the lateral midfoot when feet were unshod, suggesting that the lateral column elongated and depressed more - building up the midsole in that area seems an odd place to take that finding.

    Still other companies go from heel to ball with more of a simple ramp.

    Is there any coherent research or even philosophy behind these various midsole contours? Or is is primarily tradition?

    BTW, does anyone know where to find those old video fluoroscopes of bare and shod feet by Green? Kevin Kirby has referred to them several times on this forum.
  17. drsha

    drsha Banned

    Do your findings concur with my anecdotal fincings that in fact,
    rearfoot pronation of the STJ on the frontal plane (by definition, pronation) is not the major compensator in gait.

    Instead, it is sagital and transverse plane collapse at the STJ and more profoundly, the MTJ.

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