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Orthotic posting and the triple interface

Discussion in 'Biomechanics, Sports and Foot orthoses' started by Robertisaacs, May 21, 2009.

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    I've been meaning to post this for a while, never got around to it.

    One of my pet peeves, as I sit in my armchair tugging on my pipe, is the way that as biomechanists we often fail to consider the triple interface when prescribing orthotics.

    For them as does not know, this is the often overlooked reality that there are three interfaces to consider. How the foot sits on the orthotic, how the orthotic sits in the shoe and how the shoe sits on the ground.

    In the lab I am often met with the heart-warming sight of somebody placing an orthotic on a shelf and squinting down its length for balance and to check for the 4.75 degrees:pigs: of medial rear foot wedge they put on. Which, of course is fine and dandy. But what then? We put the insole in the shoe / trainer.

    Now when I issue insoles I tend to first send them off to buy some decent shoes. Usually these lace ups have a nice cushiony liner. I’m sure you know what’s coming now…

    The ORF of a device is exerted between the device and the surface it rests on as well as between the device and the foot. And if the modifications (varus wedge, Kirby skive, whatever) are designed to increase ORF on the medial side of the foot they will proportionately increase it on the medial side of the shoe liner.

    6 months later the patient returns. If they have a “standard” type of polyprop device with a heel block, the wedge the medial side of the heel block has sunk slowly in the west by, oh about 4.75 degrees! :bash:

    Aha, I hear you cry, but what of the forefoot. Surely if the device is balanced the forefoot will keep the insole in the desired angle. Well yes, except that the EDGE of the insole digs in more than the heel! And if some helpful lab tech has cut the distil / medial corner off to plantar flex the 1st ray, a modification which for the very life of me I cannot understand, the insole is basically pointy. :sinking: If the distil end has been made narrow to accomodate narrow shoes we have the same problem.

    Sometimes I even see shells with NO heel block at all, just a heel cup as rounded underneath as it is on top. Might as well put them on a wobble board as far as I can see!

    Obviously this is less of a problem with shank dependant devices as the ORF UNDER the device is spread over a larger area. It varies dependant on the length of the heel block, I’ve seen some with a heel block extended into the arch and others where it is only 15mm or so from the back of the heel.

    What is the point of the excruciating care with which we cast our feet, and the delicate skill and engineering knowledge with which we apply our modifications if the damn thing does not sit in the shoe right?:deadhorse:

    Anyway. Half rant half enquiry. What say you all?


    PS, Got some good photo's of this when I get time to upload.
  2. Peter

    Peter Well-Known Member

    Thought i'd stumbled across a grumbleflick when I started to read Roberts post:rolleyes:
  3. "Triple Interface" sounds like a term that should be patented and trademarked. I was very disappointed, Robert, that you weren't going to try and make some money off this new term.:rolleyes:
  4. Graham

    Graham RIP


    You/ve heard this before, but without a first ray cut away the first ray is held at the same level as the lesser metatarsals thefore limiting and delaying hallux extension. The first ray needs to plantar flex to allow the big toe to bend. Don't you think.

  5. This is interesting. Can you point me to the research which has demonstrated the effects of foot orthoses with and without first ray cut-outs on the kinematics of the 1st metatarsal? Also, if using a 3/4 length shell aren't al of the metatarsal heads in contact with the inside of the shoe and therefore at the same level whether there is a cut out or not? If I walk barefoot, does my first metatarsal head some how push its way into the tarmac? Indeed, given the bulk of the sesamoid apparatus, could we not argue that the first metatarsal head is relatively dorsiflexed compared to the lesser metatarsal heads?

    I've always had a problem with the idea that the foot cannot move in the space above an orthosis.
    Last edited: May 21, 2009
  6. Actually, it's common for there to be a quad-interface (patent pending): foot- hosiery; hosiery- orthotic, orthotic-shoe, shoe-ground.

    I've also, looked at penta, hexa and septa interfaces (copyright) that take into consideration the component layers of running shoes. ;):pigs:
  7. Moreover, they then walk on a terrain that varies in angulation and place their devices into shoes of varying geometry. Yet despite this, 7% of respondents believe that they are being rational when they grind the rearfoot posting angle into their devices (Kevin and someone else ;)) http://www.podiatry-arena.com/podiatry-forum/showthread.php?t=6603
  8. Good point! :drinks I'll get on the phone and

    DAMN IT!!! TOO SLOW AGAIN!:bang:

    Kind of a scummy trick Simon, to take an idea someone else had, tweak it slightly then patent it! ;)

    Seriously though. We pay such extreme care over the interface between the insole and the sock (thanks simon:rolleyes:). The behaviour of an insole against a shoeliner varies so greatly yet we tend to ignore it!

    Just so!

    If the base of the met is at the peak of the insole and the head of the met is on the ground then surely it does not matter a damn whats under the shaft. The only way to planterflex the 1st ray is to either raise one end (higher arch) or drop the other (reverse mortons / kinetic wedge). Cutting the corner off the shell does neither although many's the time i've seen it lower the base of the 1st cos without the medial part of the distil edge to buttress, the insole rolls inward in the shoe.

  9. Sneak preview of my amazing new PATENTED orthotic material, the Hepta-Icosa Interface Gait Substrate.

    Also available as hexadeca for people with less room in the shoes. Can be beveled easily and is environmentally friendly. Allows lateral shear. Very exciting stuff!

    Keep it dark...:cool:


    Stole a march on you there Spooner, with your pedestrian old style penta, hexa and septa interfaces !:cool: Out with the old and embrace the new!

  10. I seem to recall you crediting the concept of the triple interface with me in the first place! :D
  11. efuller

    efuller MVP

    On the street you can call it Hecka Deca. I'll send you may address so you can mail me the advertising consultant fee.


  12. efuller

    efuller MVP

    I agree that the multiple interfaces will make exact measurement of "correction" moot. However, I still feel that you need a way to describe to the lab technician how to put more or less skive in the device. When I was teaching I took a cast of my foot and pressed an orthotic over it. Then did a medial heel skive and pressed an orthotic. I could feel the difference between those two conditions. Then I took the orthotic and added a rearfoot post (heel block?). I could feel that difference. I then added additional material to the plantar surface of the medial side of the post to invert thedevice more. I got to the point where in my medially deviated STJ axis foot that my peroneal muscles were getting fatigued walking a city block. Then I removed the extra material and no more peroneal fatigue. Then I removed some of the post under the medial side of the heel and it the orthosis felt a little softer at contact and still felt like it was supinating me more than when I removed the rest of the post. Try it.

    So, I guess the point is that even if the orthotic is sinking into the shoe, a skived orthotic, or an orthotic with a rearfoot post, would be doing more than an orthotic without that modification. What it does will vary with the shoe, and the age of the shoe.


  13. Robert writes: "Sneak preview of my amazing new PATENTED orthotic material, the Hepta-Icosa Interface Gait Substrate.

    Also available as hexadeca for people with less room in the shoes. Can be beveled easily and is environmentally friendly. Allows lateral shear. Very exciting stuff!"

    Simon replies:
    Robert, I'll challenge you, I'm coming to London with my cat, we could both treat a patient, me with my quad system and you with your hexa deca and my cat with the septa we'll let the patient decide which is best.

    I'd love to debate this with you, but I don't understand your terminology. What is this "shear" that you speak of?

    Mr Twat
  14. Graham

    Graham RIP


    You are correct. That is why i use a full length device with a reverse morton's ext to create the drop for the first metarsal.

    Your foot was not designed to walk on flat tarmac! therfore it has to compensate for this regular surface. The sesamoid/first mtpj joint complex is a functional unit, requireing the first ray to plantar flex for hallux extension. I have a ref somewhere, I'll try and fish it out. Basically states for every 1deg of first ray dorsiflexion you lose 4 deg of hallux ext.

  15. Graham, you've managed to avoid the moot point. I'm not disputing the relationship between first metatarsal dorsiflexion and first metatarsophalngeal joint extension. I'm questioning the effect of cut-outs in the orthosis shell. You first need to show that the orthosis without a cut-out dorsiflexes the first ray, then you need to show that the orthosis with the cut -out somehow plantarflexes the first ray since you stated:

    I'll ask again, where is the research which demonstrates a difference in kinematics of the first metatarsal in orthoses with and without a first ray cut-out...

    I'll ignore the flat surface thing for now...
  16. Agreed. Its the pre met shells on their own with the corner cut off that make me :craig:.

    Thats an interesting idea and one I'd love to dispute. Is there any chance some passing admin might crack the relevant posts onto their own thread? I think it deserves it!
  17. Mr Twat stated

    Robert, I'll challenge you, I'm coming to London with my cat, we could both treat a patient, me with my quad system and you with your hexa deca and my cat with the septa we'll let the patient decide which is best.

    I'd love to debate this with you, but I don't understand your terminology. What is this "shear" that you speak of?

    Robert replies

    I'm afraid I can't take your offer seriously until I've seen an published study which shows the presence of both you and your cat in London. I'm not making the journey to try on your say so that you'll be there! ;)

    Thanks for dragging us back to the point Eric. As you say an orthotic with more varus modifications should be more varus than one without even if it sinks some. However the soft base / short heel block will attenuate it some.

    Lets say X is the post on the insole. Y is the amount of sink.

    The actual post say Z, is X - Y.

    Now as you say if you add 2 to X (by means of an extra post) then you add 2 to Z.

    But how often, when we prescribe, and shoot for a desired value of Z do we consider Y?

    I contend that a part of the presciption process should be knowing what Y is. If its lots then one needs to either increase X (more post) , or decrease Y (by lengthening the heel block, using a shank dependant device or altering the shoe.)

  18. You are assuming that x, y and z relate to orthoses efficacy. Do they? What about if I don't just want to wear my £1000 orthoses in one pair of shoes?
    Not necessarily. Think about what you have written z= x- y, right? What is the relationship between x and y?

    Robber said: "I'm afraid I can't take your offer seriously until I've seen an published study which shows the presence of both you and your cat in London. I'm not making the journey to try on your say so that you'll be there! "

    Dude, I've got tickets for U2 at Wembley- do you think I'd miss this?
    Last edited: May 21, 2009
  19. Graham

    Graham RIP


    Nothing scientific enough for you. Although Kevin's impressive and well thought out theoretical publications (not said in a sarcastic sence) appear to adequate for your tastes.

    Plenty of F-SCAN studies which demonstrate this effect nicely. Although I forgot, the human eye is far more scientifically accurate than an F-SCAN. (sracastic but meant in good humour)

  20. How can f-scan measure first metatarsal kinematics?
  21. Graham

    Graham RIP


    It can't. What it can dmonstrate is whether the first MTPJ is loading in a timely fashion, if the first ipj is loading prios to the first mtpj, if there is a early or late heel lift ect. It can then demonstrate if the device you are using is improving these parameter. Of course you know that don't you?

  22. That's funny because I could have sworn I asked you:
    To which you answered:
    Now, I'm not clever enough to understand sarcasm, so I asked:

    To which you answered:
    Glad we got that cleared up. So what you are saying is that you cannot provide any evidence for your contention that foot orthoses with a cut-out beneath the first metatarsal segment influence the kinematics of the first metatatarsal- right?

    With regard to the rest of your post, I have no idea what a "timely fashion" is. Since you have mentioned these things what time should the heel lift? About half past nine? (sarcastic but meant in good humour) How do we know what is an improvement for these parameters?
  23. Graham

    Graham RIP


    Zzzzzzzz! You know the answer to this You've talked to Howard and Bruce plenty of times. You're just not prepared to use the availble technology and until you do you will never see and interpret the data which is available.

    Good night:deadhorse:

  24. Graham,
    For your information, I've used the available technology many, many times. I've even published a paper using F-scan. So, sleep on that. I just can't recall ever getting satisfactory answers to the kind of questions I've just asked of you from any of the proponents of pressure analyses systems. Seems that I'll have to keep waiting.

    Lets see if we can help Graham climb off the hook he hung himself on earlier:


    Foot orthoses with a full width shell limit 1st MTPJ dorsiflexion, not by dorsiflexing the first metatarsal, but by increasing the tension in the plantar soft tissues passing beneath the shaft of the first metatarsal and inserting into the hallux through direct pressure on these structures, in so doing this increases the hallux plantarflexion moment about the first MPJ and increases hallux dorsiflexion stiffness. By cutting away the orthoses shell beneath the first metatarsal the tension in these soft tissues is relatively reduced, since the direct pressure upon them is reduced, resulting in a concomitant reduction in hallux dorsiflexion stiffness.

    No evidence, just an alternative hypothesis.

    Sweet dreams. Go "beat your own dead horse" to sleep.

    I'll provide you with a little experiment you can perform to test this hypothesis tomorrow.
    Last edited: May 21, 2009
  25. efuller

    efuller MVP


    I think of it as more of part of the adjustment process. You make your first best guess and then if it doesn't work you add a little or remove a little based on SARLE. I'm not sure that in a busy clinic that we can gather enough information to make a well researched prescription. You would have to start taking into account things like the age of the midsole of the shoe as it effects durometer; the temperature at which the shoe will be used; etc. I don't want to think that hard and I don't want to have to measure all of the possible parameters that could change the amount of z. There is probably a range of successful prescriptions, ie no one right answer. I think the succesful biomechanics practioner really earns their reputation when they are able to fix the first attempt that did not work.



  26. Hmm.

    The null would be that the frontal plane orientation of the device and arch height have NO effect on orthoses efficacy.

    Do they not?

    If we accept this null then there would be no point in using wedges or skives.



    PS on reflection I can think of one model which says this...
  27. Robert:

    First of all. I think what you are calling a "heel block" is standardly called a "rearfoot post" here in the States. Is "heel block" a commonly used term? I have never heard this term before.

    I do tend to agree with your assessment that putting in a "first ray cutout", where the medial section of the anterior edge of the orthosis is removed to presumably allow first ray plantarflexion, would tend to very significantly reduce the frontal plane stability of the orthosis inside the shoe. I never use this "first ray cutout" modification, and have never seemed to have a problem from not doing so.

    You can't assume that just because the sockliner or insole of the shoe has a dent in it that the orthosis sits exactly at the angle of the dent upon weightbearing force from the individual. In addition, the pressures are so great at the anterior edge of the orthosis that nearly all softer sockliners/insoles will fully compress, both medially and laterally, within a few weeks of putting an orthosis on top of them so the angular change is probably slight.

    Your overall observations and understanding of your "triple interface"certainly are important and something that many podiatrists never evaluate for when they are wondering why their foot orthoses are not "correcting" as much as they thought they should. John Weed, DPM, spent quite a bit of time lecturing to us 2nd and 3rd year podiatry students about looking for the imprint of the anterior edge of the orthosis to determine what type of forces the orthosis are being subjected to. A medial dent anteriorly meant pronation forces and a lateral dent meant supination forces from the foot.

    Probably much worse, however, is the angular change of the shoe midsole of shoes over time due to compression set of the shoe midsole material. Compression set is a time dependent phenomenon of midsole materials such as ethylene vinyl acetate (EVA) whereby the small air bubbles within the material break and settle, causing the midsole to no longer be a uniform thickness from medial to lateral on the shoe sole. I believe that many of the problems with today's shoes, and possibly many of the foot injuries we see as podiatrists, come from people buying shoes that are too soft and wearing them too long due to the inevitable compression set that occurs in the midsole, which obviously is much more apparent with people who are heavy or are very active compared to lighter individuals who are more sedentary.

    Therefore, when I am evaluating patient's shoes/orthoses as to why their foot is not functioning the way I think it should, I first look at the shoe from outside to make sure the heel counter is vertical and no compression set has occurred, then I have the patient stand on the orthosis barefoot so I can see how much the orthosis deforms under their body weight and then I look inside the shoe. All of these factors play an important role in ensuring optimum orthosis function for the patient.
  28. http://www.podiatrytoday.com/article/475

    The digging in of the rearfoot post as an indicator of moments: if the rearfoot post has "dug" in medially this suggests that the eversion/ pronation moment from the foot > than the supination from the orthosis + shoe. Clinically, this can be a useful indicator of the forces being exerted. This is what Kevin was intimating when discussing John Weeds lectures- right Kevin?

    That experiment- Do a weightbearing jacks test on a subject- feel/ measure the dorsiflexion stiffness of the hallux; now press up into the soft tissues just proximal to the 1st MTPJ and repeat the test, while the kinematics of the first metatarsal are unchanged (it's in the same position) the dorsiflexion stiffness of the hallux increases- right? Kinetics versus kinematics.
  29. Exactly. If the sockliner/insole/midsole of the shoe shows signicantly increased indentation medially versus laterally, then that is an indication of increased compression set of the medial sockliner/insole/midsole and probably that the orthosis is everting into the shoe more than it is inverting into the shoe for the time the shoe-orthosis combination is being worn. This is a fair clinical indicator of whether the orthosis is "controlling" the pronation well or not, but in general, in more severely pronated feet (i.e. those with more significantly medially deviated STJ axes), the medial orthosis edge will nearly always dig a deeper groove than will the lateral orthosis edge. Even though John Weed didn't exactly say it like this, I believe that this is what he meant.

    The problem with relying too much on this anterior edge indentation patten is that the medial arch of the orthosis is invariably higher and drops at a steeper angle distally than the lateral arch of the orthosis, and as such, there will be much more surface area of contact of the distal lateral orthosis plate (i.e. distal 3-4 cm of plantar plate) than will be present at the distal medial orthosis plate. Because of this, the plantar contact pressures of the anterior orthosis edge will invariably be greater medially in most shank-independent orthoses (I love that term Simon!!;)) than laterally. This will also significantly affect the anterior edge indentation pattern so I don't get too excited about this clinical finding from the inside of the shoe unless it is fairly extreme.
  30. Here we have a couple of articles which demonstrate an increase in plantarflexion of the first metatatarsal with foot orthoses that don't incorporate a first metatarsal cut-out. Despite the increase in first metatarsal plantarflexion, the second study reports a decrease in 1st metatarsophalangeal joint dorsiflexion. So perhaps the idea that limitation of hallux dorsiflexion is due to 1st ray dorsiflexion when wearing foot orthoses needs a rethink. Hence my hypothesis above.

    (Edit-It doesn't want to automatically parse links in text so I've copied the text)

    J Orthop Sports Phys Ther. 2004 Jun;34(6):317-27.Links
    The effect of forefoot and arch posting orthotic designs on first metatarsophalangeal joint kinematics during gait.

    Nawoczenski DA, Ludewig PM.
    Department of Physical Therapy, Ithaca College, University of Rochester Campus, Rochester, NY 14623, USA. dnawoczenski@ithaca.edu
    STUDY DESIGN: Repeated-measures analysis of variance. OBJECTIVE: To examine the effect of 2 different orthotic posting designs on first metatarsophalangeal (first MTP) joint kinematics during gait. BACKGROUND: Common orthotic designs used to control abnormal pronation incorporate the use of a medial post in the forefoot and/or rearfoot locations. Although this design may favorably alter rearfoot and lower-limb kinematics, the incorporation of a forefoot post has been theorized to negatively impact first MTP joint function by limiting hallux dorsiflexion during push off. An alternative design that has been proposed to be more favorable for function of the hallux and first metatarsal is the medial arch support. METHODS AND MEASURES: Eighteen subjects with a mean age of 28.2 years (SD, 8.3 years) completed the study. All subjects were judged to have excessive pronation based on a clinical orthopaedic examination. Two different pairs of orthoses were custom molded for each subject. One design incorporated an extrinsic rearfoot and forefoot post and the second design had a high medial longitudinal arch in combination with an extrinsic rearfoot post. The "Flock of Birds" electromagnetic tracking device was used to collect 3-dimensional position and orientation data of 3 body segments (hallux, first metatarsal, and calcaneus) during the stance phase of walking for 3 conditions (no orthosis and each of the 2 different orthotic designs). A repeated-measures analysis of variance was used to assess differences in first MTP joint dorsiflexion at midstance and during the push-off period of gait, as well as metatarsal declination angle changes during relaxed stance. An exploratory regression analysis was used to investigate factors that related to the change in peak dorsiflexion for the orthotic conditions. RESULTS: Peak first MTP joint dorsiflexion averaged between 38 degrees and 40 degrees across all conditions. Although slight increases in first MTP joint dorsiflexion values were noted with both types of orthotic designs, these differences were not significant at either phase of the stance cycle (P = .50). The metatarsal declination angle in relaxed stance significantly increased (P = .001) under both orthotic conditions. Considerable individual variability was present. For the rearfoot-forefoot posted orthosis, a change in the declination angle of the first metatarsal during relaxed stance with the orthosis was a significant nonlinear predictor of change in peak dorsiflexion during push off. CONCLUSIONS: Foot orthoses that incorporate a medial forefoot post do not have a consistent negative effect of reducing first MTP joint dorsiflexion during walking.


    J Manipulative Physiol Ther. 2006 Jan;29(1):60-5.
    The influence of two different types of foot orthoses on first metatarsophalangeal joint kinematics during gait in a single subject.

    Michaud TC, Nawoczenski DA.
    OBJECTIVE: To quantify the effect of two distinct foot orthotic designs on in vivo multisegment foot and leg motion; in particular, the first metatarsal and first metatarsophalangeal (MTP) joint during gait. METHODS: A 23-year-old man had an excessively pronated foot structure as measured during a clinical orthopedic examination. The Optotrak Motion Analysis System was used to collect three-dimensional position and orientation data from four modeled rigid body segments (hallux, first metatarsal, calcaneus, and tibia) during the stance phase of walking. The subject walked at a self-selected comfortable walking speed, and a minimum of five trials were collected under three different test conditions: no orthosis, semirigid orthosis with a varus post, and a semirigid orthosis with a varus post and a large medial flange. Data were normalized to the stance period, and descriptive statistics were calculated for dependent variables. RESULTS: Both orthotic interventions equally modified first MTP joint motion when compared with the no orthotic condition. First MTP joint dorsiflexion was decreased (>2 SD) with the orthosis during terminal stance phase. This decrease was associated with a concomitant increase in first metatarsal plantar flexion. CONCLUSION: A custom-made semirigid orthosis posted medially and made from a neutral position off-weight-bearing plaster cast can alter motion in the forefoot during the propulsive period by increasing first metatarsal plantar flexion and decreasing excessive first MTP joint dorsiflexion.
    Last edited: May 23, 2009
  31. Simon:

    It would be interesting to speculate what exactly was going on in these two studies that showed increased first ray plantarflexion and decreased 1st MPJ dorsiflexion with foot orthoses. I wonder if this could this be attributed to the heel lifting effect of the orthosis alone?
  32. Ah the cud, it tastes good this week!:drinks

    Hmmm. Obviously this depends on how the cast is taken and whether one fancies a PF groove (which is terminology which SHOULD catch on because it sounds :cool:). However I suspect one would have to push pretty hard on these tissues to cause a significant increase in internal plantarflexion moments at the MPJ.

    Rather than the experiment above, how about one stands the foot on an orthotic and tests the dorsi stiffness then saws the corner off then tests it again... I just don't think that the medial border of the distil end of the orthotic pushes into those tissues that hard!

    If one DID, then I would think manually planterflexing the 1st ray when casting, or adding a little plaster to that proximal area would acheive the same reduction of pressure without reducing the stability of the device in the shoe.
    I'm really not sure! I did'nt want to describe it as a wedge because I was not sure if that applied to the squaring off of a heel not being wedged in either direction :eek:. So long as we know what we mean.

    Fair point. Might compress the lateral side to the same degree when the person puts loads the device. Then again, might not. If the shoeliner has dented medially and not laterally then at the very least it is equivilent to adding a lateral wedge made of the shoeliner material, to the thickness of the dent to the insole.

    Fair enough. Observation and correction after the event are certainly a good deal more reliable than trying to predict / quantify before the event.

    It is, perhaps, just something to be aware of before prescription and something to look for on review. Also when deciding on whether to go for a Non shank dependant, shank dependant, or partially shank dependant device* it may be worth bearing in mind. There's a thread somewhere on the relative merits of SD vs NSD devices, don't know if this was on there or not.

    Thanks for all the thoughts.


    * I made that one up. Its how I refer to a device like a 6mm high density EVA shell. Initially it is non shank dependant, there is air under the shell. It deforms as per its characteristics just as a polyprop device but when the underside of the shell meets the shank it behaves like a Shank dependant device because it is thicker under the medial part of the arch than the lateral (where it has been ground away). Its not really SD, because the initial degree of resistance is determined by the materials stiffness nor NSD, rather its both at different levels of load. **

    ** Problem Simon:rolleyes:;). Look, I know its not strictly accurate but it is useful for the sake of brevity unless you can come up with something better!
  33. What if we cut more substantial portion of the shell away, say back to just distal to Lisfrancs joint?. Perhaps, Robert, you could provide an alternative hypothesis, in light of the research that suggests foot orthoses limit hallux dorsiflexion (Kilmartin's bone pin study for example) and the research that I quoted above, which suggests that foot orthoses increase first ray plantarflexion?

    Like Kevin, I rarely use first ray cut outs for the reasons you outline above.
    Last edited: May 23, 2009
  34. Only one of the studies showed a reduction, the other showed an insignificant increase. Heel lift effect may have been significant in the reduction study. We talked about this here:
  35. And there Robert is your first JAPMA paper. Go experiment. All you need is a set of weighing scales:


    A climbing sling:

    A protractor

    And some willing subjects.
    Make up some devices. And start chopping. Why not perform the non-weightbearing type Jacks test ala Bruce Williams, mark the point where the hallux dorsifexion "gives", then start systematically cutting the shells back- see how this relates to the marked point.

    I'll help you with write up if you need some help. Look forward to reading it!

    Nice little study.
  36. No, Robert, I still don't know what you exactly mean by a "heel block". In my 25 years of teaching biomechanics around this small planet of ours, I have never heard of this term. Therefore, if you want me, and probably many others trying to follow along, to understand what you are saying, then we need a definition of what a "heel block" is, since I assume it is not a rearfoot post. Is 'heel block" another term you made up or have you seen this term used elsewhere in the medical literature? If the answer is the former, then you need to define these terms in order for you to be understood and so that we can make sense of what you are saying.

    Thanks in advance.:drinks
  37. One more for you Robert during this stream of consciousness, how does a plantar fascial groove "work"?
  38. Simon:

    I enjoyed the paper both before and after publication.:drinks

    I would love to see this paper repeated using a 3-D motion analysis. Maybe in another lifetime, Dr. Spooner?

    For all of those who don't have access to this nicely written paper, here it is for your reading pleasure. It should really be read by all of you who have an interest in first ray/1st MPJ biomechanics.
  39. I'd guessed that when the first review came in :drinks

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