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Foot orthotic disagreement

Discussion in 'Biomechanics, Sports and Foot orthoses' started by richardrobley, Mar 22, 2012.

  1. richardrobley

    richardrobley Active Member


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    This patient is suffering from lateral left ankle pain and right Achilles tendon pain. No stiffness in any of the joints. Currently seeing our physio but due to have orthotics fitted soon. Bit of a disagreement in the clinic, would love to hear some opinions on type of orthotic needed.
     

    Attached Files:

  2. Re: orthotic disagreement

    Almost impossible to give you any ideas with that picture and the info we have

    Diagnosis

    why it mechanically stress

    ways to reduce the mechanical loads on stressed tissue

    rehabilitation treatment

    review

    .............................................................

    so what is your exact diagnosis ?

    and I will leave you with a few thoughts

    It is ok to have different orthotic designs from one side to the other or even just one device.

    it is ok to treat Achilles issue without using an orthotic at all

    do not build a device which will increased the loads on the stressed tissue
     
  3. G Flanagan

    G Flanagan Active Member

  4. efuller

    efuller MVP

    Re: orthotic disagreement

    Left lateral ankle pain can be sinus tarsi syndrome or peroneal tendonitis. Those are treated almost exactly oppositely. Maximum eversion height test. If there is a lot of range of motion in the direction of eversion it's probably not sinus tarsi syndrome. If it hurts for them to evert while doing the test and there is a high range of motion available, it's more likely that it is a peroneal tendonitis.

    Eric
     
  5. RobinP

    RobinP Well-Known Member

    Re: orthotic disagreement

    I think that this thread raises an interesting point. So many of us on here are now treating patients based on tissue stress theory, one forgets that other health professionals will almost certainly not have been taught that way(ie to think like an engineer).

    I spend an inordinate amount of time talking to physios, chiropractors, running store owners and orthopaedic registrars about myth busting when it comes to treating patients. eg pronation is bad and everyone should have a nice vertical heel. flat shoes are good for everyone, etc

    It is our job to educate others, but you have got to use some hard evidence. What I think will surprise most people reading the original post is that orthotics are being provided without a diagnosis for the lateral ankle pain

    Perhaps with the achilles tendinopathy, one could argue that making the TA more mechnically efficient will reduce the tissue stress and, regardless of anything else inverting the heel and raising the heel might work

    However, the wrong device on the lateral ankle pain could make matters significantly worse. Completely agree with Eric, you need to form a diagnosis as the two aforementioned pathologies have diametrically opposing solutions.
     
  6. richardrobley

    richardrobley Active Member

    Re: orthotic disagreement

    Sorry for the lack of detail but I started this thread on my phone while I was still in clinic.

    On examination the patient presented with 'normal' ranges of motion at the stj, mtj and 1st mpj. She experiences pain when I maximally pronate at the stj which could be a sign of sinus tarsi syndrome. Pain is also felt when pressing around the anterior talofibular ligament and directly below the lateral malleolus.

    Non weight bearing position looks 'neutral'.

    Small heeled shoes are very uncomfortable and supportive walking boots are very comfortable.

    The disagreement we're having is the photo appears to show a varus calc position when weight bearing. However, is this just ankle swelling and fatty tissue around the ankle and foot.
     
  7. Re: orthotic disagreement

    Richard don´t treat the foot treat the condition

    ie if there is pain on pronation of the STJ - Supinate the foot

    or vice versa

    as for the Varus heel could be could be fatty tissue could be swelling - does not really matter

    so if we have Richard on 1 side and Co-worker on the other - and in the middle reduce loads on the stressed tissue - I would go the white picket fence option.

    :D
     
  8. efuller

    efuller MVP

    Re: orthotic disagreement

    Using the old terminology, a partially compensated varus foot will look "neutral" and may have a varus heel, but still sit at its maximally everted position. The partially compensated varus foot can have sinus tarsi pain because the floor of the sinus tarsi is what is stopping further eversion. So, if you decrease the pronation moment form the ground, this will decrease compression in the floor of the sinus tarsi.

    Eric
     
  9. dragon_v723

    dragon_v723 Active Member

    may be a bit rrude but may be obesity is the root of these issues...
     
  10. drhunt1

    drhunt1 Well-Known Member

    Richard Robley-This patient clearly has an uncompensated varus deformity, in the hindfoot at least, and perhaps in the forefoot as well. The swelling on the lateral aspect of the foot, is not just adipose, but, IMHO, swelling of the peroneal tendon sheaths. This patient is laterally unstable, because the patient is maximally pronated at the STJ, rendering peroneal function useless. An AP radiograph would show met adductus as a lifelong compensation for the rearfoot varus deformity. She probably has a history of lateral ankle sprains, cannot wear high heeled shoes, has felt like a "clutz" most of her life, and walks in a guarded fashion when stepping off of curbs, etc. Correct?

    An orthotic needs to address the rearfoot, with at least a 6 degree varus wedge, a lateral buildup on the orthotic that extends to the C-C jt, no lateral skive to the rearfoot post...and that doesn't address the forefoot, which might also require a varus wedge. Make the orthotic wide. Let me know if this helps.
     
  11. efuller

    efuller MVP

    Welcome to the arena, Dr. Hunt.

    I don't think that you can say definitively, from the picture, that this is an uncompensated varus, foot. You will be right some of the time making that assumption. The additional clinical information does make me lean more toward uncompensated varus. However, a rigid forefoot valgus can look just like that.


    There are different reasons for lateral instability. In sinus tarsi syndrome you have increased peroneal latency. In rigid forefoot valgus foot you often have a laterally deviated STJ axis.

    The peroneal tendons will be useless only in the sense that they cannot produce further pronation motion when the STJ is maximally pronated. However, they can still produce a pronation moment and are not totally useless.



    Metadductus a compensation for rearfoot varus? How does that work?


    I'm curious as to what you mean by a 6 degree rearfoot varus wedge. Are you talking about a medial heel skive or balancing the cast 6 degrees inverted? I'd have no problem with a lateral bevel under the lateral side of the rearfoot post if my goal was to increase supination moment. Why the flat rearfoot post?

    One test to see if the patient needs a forefoot varus wedge is to have them stand relaxed and try and work your fingers under both the lateral and medial forefoot. The foot that needs a varus forefoot varus wedge will have little force on the first met head (you can get your fingers under there) and have a lot of force on the lateral forefoot (you can't get your fingers under there.) That's an old test that John Weed taught. However, I don't believe that he used forefoot varus extensions on his orthotics. So, I use his test, but use the information from it slightly differently than he did.

    Eric
     
  12. drhunt1

    drhunt1 Well-Known Member

    Eric-I stated that the patient clearly had an uncompensated varus deformity because at static stance, she is still inverted. The met adductus is compensation, which begins early in life, to bring the forefoot, (medial column), down to the supporting surface. It appears from the picture, especially on the left foot, that this is barely achieved...thus the "C"-shaped foot. The sinus tarsi syndrome and swollen synovial sheaths of the peroneals are a result of this deformity, as the STJ is subluxed at static stance/forefoot loading, and the peroneals are experiencing overuse type problems. I stated that the peroneals are rendered useless, because at maximal eversion of the STJ, the peroneals can no longer provide lateral stability, (you called it a pronatory moment)...thus the patient tends to chronically sprain their ankles, "feel lke a clutz", and are cautious when engaging uneven terrain, or stepping off a curb.

    I was referring to balancing the orthotic with a 6 degree rearfoot post, in order to hold the STJ in a more "neutral" position, ie., don't let the STJ maximally pronate, (evert). [This patient would have been a good candidate structurally for a Dwyer calcaneal osteotomy] But if the rearfoot is held in a more inverted position, then the forefoot would need to be evaluated for a varus wedge as well. Hope this helps explain my thoughts...
     
  13. Jeff Root

    Jeff Root Well-Known Member

    I’m in general agreement with Dr. Hunt. An open chain evaluation of the range of motion of the STJ would confirm whether the patient is maximally pronated in resting stance, which a believe she probably is. The peroneals are attempting to pronate the foot in an effort to prevent ankle inversion and lateral postural instability, which is probably present in relaxed stance and during gait. But because the rearfoot remains inverted with maximum pronation of the STJ, the foot has a constant tendency for lateral instability (inversion) at the ankle joint. I’m betting the forefoot is slightly everted to the rearfoot and contributes to or is the result of an inverted rearfoot over time (likely a plantarflexed 1st ray). Obesity is a significant contributing factor and should be addressed in treatment.

    I would correct the rearfoot inverted but just a few degrees from maximum pronation and use a very high lateral heel cup and a zero degree rearfoot post with a lateral post flare to resist further rearfoot inversion. If the forefoot is everted to the rearfoot, I would be sure to incorporate intrinsic forefoot valgus correction in the device and possibly use a valgus forefoot extension to the sulcus.

    Jeff
     
  14. efuller

    efuller MVP

    Are you aware of what has classically been called a rigd forefoot valgus. This foot will also exhibit an inverted calcaneus. So, I maintain, from the picture, you can't tell whether this is an uncompensated varus or a rigid forefoot valgus foot. This is where the Coleman block test is used to differentiate between these two foot types. (The maximum eversion height test is essentially the same as the Coleman block test.)

    There may be a correlation between metadductus and rearfoot varus. I'm not sure that there is. Regardless, correlation is not causation.



    The Talliard article showed that with sinus tarsi syndrome there was a decrease in peroneal activity. Clinically, I don't see peroneal overuse with sinus tarsi syndrome. The theory for why I don't see this is that sinus tarsi syndrome is caused by the STJ being at its end of range of motion in the direction of pronation where the lateral process of the talus is in contact with the floor of the sinus tarsi. It hurts for the peroneal muscles to push these bones together harder and that is why you see decreased peroneal activity in sinus tarsi syndrome. The other bit of information that you can get from examining this anatomy is that it's nearly impossible for a STJ to sublux in the direction of pronation. The end of range of motion is bone on bone and there is room for further motion.

    Now a rigid forefoot valgus foot will often have peroneal overuse.

    I disagree that the peroneals are useless in providing lateral stability. The peroneals can still contract to prevent inversion sprains. However, there are studies that show that sinus tarsi syndrome also has an increased peroneal reaction time. My theory is that the peroneal muscles are inhibited because when they are active they will increase the pain in the sinus tarsi. So, when they do hit uneaven terrain, it will take longer for them to respond to uneven ground that causes an unexpected inversion motion as you described. The reason that an varus wedge type orthotic is effective is that it decreases the compressive forces in the floor of the sinus tarsi. The Talliard article showed that normal peroneal firing returned when local anesthetic was injected into the sinus tarsi. So, if the pain is removed you get normal firing.

    I was just having a problem with your terminology. Where I was taught, a rearfoot post was extrinsic and added to the bottom of the orthotic. We were taught that when you used a degree measurement when talking about the rearfoot, it usually referred to the heel bisection when the cast was balanced. I agree that this orthotic modification would help the partially compensated rearfoot varus foot, but would be the wrong thing for the rigid forefoot valgus foot (foot with a laterally positioned STJ axis.) I'm not saying what I was taught was the correct terminology, I just want to make sure we are saying the same thing.


    The Coleman block test is used for assessing the need for a Dwyer calcaneal osteotomy.
    Eric
     
    Last edited: Mar 29, 2012
  15. efuller

    efuller MVP

    Jeff, do you agree with me that a rigid forefoot valgus could cause an inverted heel and that from looking at that picture alone, you cannot conclude that the foot had a partially compensated rearfoot varus. I would agree that either a non weight bearing exam or a maximum eversion height test could confirm that this is an partially compensated varus foot. But, that confirmation should be done before recommending treatment.


    The calcaneal bisection is not the best indicator for whether or not the STJ will tend to invert. I've seen very inverted heel bisections in a foot that had never had inversion sprain problems. A better indicator is STJ axis position. You can have a medially positioned STJ axis with an inverted and maximally pronated heel.

    You can also have a laterally positioned STJ axis with an inverted heel and this is a foot that will tend to invert even when it is maximally pronated. The foot with the lateral axis is much less likely to have sinus tarsi pain as the pronation moment from the ground would be smaller as compared to a medially positioned STJ axis foot.

    Eric
     
  16. Jeff Root

    Jeff Root Well-Known Member

    Yes Eric, I agree. For example, the patient might have a wide base of gait due to the size of her thighs and this could contribute to the inverted attitude of her heels in relaxed bipedal stance. I do suspect that she is maximally pronated but I think it needs to be confirmed by physical examination. If she has any additional range of calcaneal eversion available and is not standing maximally pronated, then it might be due to an everted forefoot producing a retrograde inversion of the heel or due to a laterally oriented STJ axis.

    Jeff
     
  17. She is a bloater, of that there is little doubt. Yet there is apparent asymmetry in heel position. If it were due to the fatness of her thighs, you'd expect it to be more symmetrical, Jeff- right? And surely a wider base of gait should reduce the "postural" varus attitude of the tibia, resulting in a decrease in inverted position of the rearfoot in a foot which is functioning toward it's end of range of rearfoot eversion?
     
  18. Jeff Root

    Jeff Root Well-Known Member

    Simon,

    I have a rearfoot varus and a mild plantarflexed 1st ray resulting in an everted ff/rf relationship. If I widen my base of gait my tibia develops a greater angle of valgum and my heel remains stationary. This effectively increases my rearfoot varus angle (increases the inverted relationship of my heel to my leg). If I stand with my legs crossed my tibia are in extreme varum and my heels become markedly everted. So a wider base of gait does not always result in increased stj pronation. Large thighs can also push the knees apart and effectively increase the varus angle of the tibia, but I don’t see a significant tibial varum.

    As for heel symmetry, I’m not sure the camera angle gives us an accurate picture of this.

    Jeff
     
  19. drhunt1

    drhunt1 Well-Known Member

    Eric-the Talliard article? The Coleman Block test? Impressive. Frankly, I have grown to use my own criteria for assessing the patients' needs. When you've been practicing this art as long as I have, you will become acutely familiar with trends and patterns, ie., patients with similar maladies with similar structural presentations. I think I have learned more from my patients over the years, than from the myriad lectures from Podiatry pundits at the seminars I have attended. I have seen the foot pictured above a hundred times...but didn't really begin to appreciate the patterns until about patient #50. ;)

    I have no desire to get into a "pissing" match about this subject with you, but I think it prudent to explain my familiarity with the picture above. If you notice the left foot, the first MPJ appears to be barely contacting the ground...and only Richard could tell us if it was easy to slip a finger underneath it...I bet it would be. That means, by definition, that the deformity is uncompensated. If Richard would be so kind as to post pics of the AP and lateral weight-bearing radiographs, I can assure you that a high degree of metatarsus adductus would be seen on AP, and the "see through sign" would be evident on the lateral view. While in theory, you're correct...a rigid forefoot valgus deformity can cause an inverted heel, but I can't tell you the last time I've ever seen one...they're rare. However, it's much more plausible that this patient has a skewfoot deformity...a combined rearfoot varus deformity with a forefoot varus deformity as well. She's beating the hell out of her STJ because it functions fully pronated at static stance, and the peroneal tendons are experiencing severe overuse syndrome in an attempt to offer lateral stability. A medializing calcaneal osteotomy with a lateral wedge removed would really help, but in the absence of surgical intervention, an orthotic that holds the STJ away from maximum eversion while supporting the forefoot deformity would offer her relief from peroneal tendinopathy, (lateral ankle pain), and significantly reduce the STJ pain.

    My inclination is to not make biomechanics so difficult, as many would like to do. I don't set my criteria of evaluation to heights that cannot be achieved through the use of orthotics themselves, which are a lot more simple in practice than in theory.
     
  20. http://www.podiatry-arena.com/podiatry-forum/showthread.php?t=1289
     
  21. markjohconley

    markjohconley Well-Known Member

    Dr Root, what a forum

    The use of the word 'correct'?
     
  22. Jeff Root

    Jeff Root Well-Known Member

    Mark, I'm Mr. Root. The use of the term correct was in reference to the manufacture of a functional orthotic device. It comes from the description of the cast modification or cast correction process. One can pour, balance or otherwise correct the heel bisection of the negative cast to a specific angle within the frontal plane. For example, if the patient in question had a heel that rested four degrees inverted when the STJ was maximally pronated , I might correct the negative cast with the heel at six degrees inverted. This frontal plane position of the heel increases the supination or inversion force and reduces stress associated with the un-resisted pronatory forces. Sorry if you misunderstood my comment but I assumed that most of those reading it would understand what I was talking about. Thank you for bringing it my attention so that I could have an opportunity to clarify it for you and any others who might not have understood what I meant. I agree, what a forum!

    Jeff
     
  23. Jeff Root

    Jeff Root Well-Known Member

  24. efuller

    efuller MVP

    I'm curious as to what your "see through sign" is. It sounds like what we used to call "bullet-hole" sinus tarsi. This sign is where there is a lot of external rotation of the talus and the lateral process of the talus is relatively far away from floor of the sinus tarsi of the calcaneus. This sign was an indication of a more supinated position of the STJ. Which is something you would see in the rigid forefoot valgus foot and not the partly compensated rearfoot varus foot.

    You won't see them if you think they are all a rearfoot varus. Paradoxically, when you try and place your fingers under the lateral forefoot of the rigid forefoot valgus foot you can find high loads laterally and low loads sub 1st met and hallux.


    The peroneals are more likely overused in the rigid forefoot valgus deformity than in the rearfoot varus deformity. The rigid forefoot valgus deformity will tend to push the foot into oversupination unless the peroneals bring the foot back to prevent ankle sprains.

    When the ground is pushing the STJ into maximal pronation, in the rearfoot varus foot, the peroneals are more likely to inactive because the ground is making it stable.



    I don't mean to get in a pissing match with you either. I'm just concerned that you may be missing a simply found difference between two different foot types. Asking a patient to try and evert their foot when they are standing and seeing if they have range of motion available is not a complicated test. If they cant evert, then you should not give them an intrinsic forefoot valgus post. I've made that mistake and it hurts.

    I'm a big believer in simplification. However, you can lose information if you make it too simple.

    Eric
     
  25. The thread linked to talks about the effect of tibial position on rearfoot position. Of specific interest was the reference to Bart's paper on the kinetic effects of genu varum and valgum

    Effects of Simulated Genu Valgum and Genu Varum on Ground Reaction Forces and Subtalar Joint Function During Gait
    Bart Van Gheluwe, Kevin A. Kirby and Friso Hagman
    Journal of the American Podiatric Medical Association
    Volume 95 Number 6 531-541 2005
    Quote:
    The mechanical effects of genu valgum and varum deformities on the subtalar joint were investigated. First, a theoretical model of the forces within the foot and lower extremity during relaxed bipedal stance was developed predicting the rotational effect on the subtalar joint due to genu valgum and varum deformities. Second, a kinetic gait study was performed involving 15 subjects who walked with simulated genu valgum and genu varum over a force plate and a plantar pressure mat to determine the changes in the ground reaction force vector within the frontal plane and the changes in the center-of-pressure location on the plantar foot. These results predicted that a genu varum deformity would tend to cause a subtalar pronation moment to increase or a supination moment to decrease during the contact and propulsion phases of walking. With genu valgum, it was determined that during the contact phase a subtalar pronation moment would increase, whereas in the early propulsive phase, a subtalar supination moment would increase or a pronation moment would decrease. However, the current inability to track the spatial position of the subtalar joint axis makes it difficult to determine the absolute direction and magnitudes of the subtalar joint moments. (J Am Podiatr Med Assoc 95(6): 531–541, 2005)

    __
     
  26. Jeff Root

    Jeff Root Well-Known Member

    Some individuals who widen their base of gait internally rotate their tibia and stj axis while other might externally rotate it. Those that externally rotate it might have increased supination (moments).

    Jeff
     
  27. We clearly showed in our paper that the genu valgum "deformity" gait pattern produced a more medial direction to the ground reaction force (GRF) vector (i.e. more medially-directed shearing forces acting on the plantar foot) that would tend to increase subtalar joint (STJ) supination moments and/or decrease STJ pronation moments. This "genu valgum supination effect" would have been accentuated during the latter half of stance phase when the GRF vector is more anteriorly located on the forefoot, therefore acting on a STJ axis that is farther from the ground, rather than in early stance phase when the STJ axis is very close to the ground and the GRF vector is located at the rearfoot (Van Gheluwe B, Kirby KA, Hagman F: Effects of simulated genu valgum and genu varum on ground reaction forces and subtalar joint function during gait. JAPMA, 95:531-541, 2005).
     
  28. Jeff Root

    Jeff Root Well-Known Member

    This just came in today. Sometimes you need to look at structure to determine that the lesion on the lateral side of this patient's foot is in fact, due to the head of the talus protruding laterally! He was casted for an AFO.

    Jeff
     

    Attached Files:

  29. ????????????????
     
  30. Jeff Root

    Jeff Root Well-Known Member

    The point is, we don't treat theories, we treat people and need to examine each of them individually. You never know what you might find!

    Jeff

    p.s. Not fair, you can't use more than five question marks! ;)
     
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