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Is surgery the only answer for an asymptomatic 10 year old "toe walker"

Discussion in 'Biomechanics, Sports and Foot orthoses' started by Rory McFadden, Mar 23, 2007.

  1. Rory McFadden

    Rory McFadden Active Member


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    Dear colleagues

    I recently assessed a healthy 10 year old boy who was referred with "flat feet"by a physio.The patient and his parents had been attending the physio clinic for a couple of months where hamstring and soleus stretches had formed the basis of the recommended treatment regime to address a "tendency toe walk".
    On examination i found his hamstrings indeed were extremely tight but it was the extreme tightness of his gastroc rather than soleus that concerned me.
    In relaxed stance his talar heads adduct and plantarflex dramatically and his forefoot abducts to "way way too many toes".
    Gait highlights a very short , flexed knee bouncing pattern where there is no heel contact when unshod.I winced as I observed the midtarsal joint attempting to cope with the lack of available ankle joint dorsiflexion, before displaying a powerful abductory twist.Needless to say that at even at 10 years of age there is already a visible thickening at both 1st MTPJ's and both 1st met/med cuneiform joints.
    The conventional soleus?? stretch that he had been carrying out only served in my opion,to encourage the talar heads to head south.

    My initial thoughts regarding my input was to cast in a pronated position and to prescribe a device which would provide a degree of support whilst not removing the foots ability to compensate for some of the lack of dorsiflexion.
    I hoped that the devices could be used in conjuction with a gastroc stretches
    to reduce the deformity that currently occurs when these are performed.The prescription could be altered as the range of available ankle joint dorsiflexion increases.

    I should add that from a relaxed stance position i can manipulate both feet to erradicate any talar bulge whilst the heels remain in contact with the supporting surface.The feet actually look good until the patient relaxes.

    I also enquired through our local paediatric Orthopaedic dept whether botulinum toxin was a treatment option to aid gastroc stretching in conjuction with POP casts or night splints.I was informed that botulinum is "not sucessful" with idiopathic toe walkers.However the Orthopod suggested TA lengthening and an osteotomy?(no specific procedure mentioned since the patient had not attended their dept).

    The term osteotomy in relation to an asymptomatic 10 year old prompted me to submit this thread.I would welcome some guidance from those of you who have encountered and managed similar children. Is it unrealistic to imagine that one can successfully manage such cases without surgery? and if this is indeed the case what are the surgical options?

    I really only want to ensure that we do the best for this kid!


    Regards

    Rory
     
  2. efuller

    efuller MVP


    A couple of ideas
    If it's not broken, don't fix it.
    First do no harm.

    An interesting thing about some toe walkers at that age is that as you watch them, on occaisional step their heel hits normally and they exhibit a close to normal heel off timing. In these kids it is a choice to toe walk. If they do it once or twice they have the range of motion to get the heel to the ground. You did not mention ankle joint dorsiflexion range of motion. Was it normal? If was, or even close, it's not broken in this child.

    You have identified some problems, severe arch flattening and evidence of high first MPJ stress. Aim to treat those and monitor the toe walking. If my child presented with your description above I would not let a TAL be done on him.

    Regards,

    Eric
     
  3. Admin2

    Admin2 Administrator Staff Member

  4. LuckyLisfranc

    LuckyLisfranc Well-Known Member

    You mention "extreme gastroc tightness". Care to put a rough figure on that?

    -10, -20 deg?

    Certainly in the flatfoot surgery I have assisted with, the determination on procedure type (for unresponsive pain insufficiently managed by conservative care) is based particularly on x-ray findings and ankle joint ROM.

    If soleus is OK as you have suggested, then a gastrocnemius recession is would be sufficient, rather than TAL. In terms of osteotomy, we have tended to consider NC fusion or Cotton, (for sagittal plane) and (lateral column lengthening) Evans procedures, depending on transverse and sagittal plane appearance on plain WB films. Graft harvest for the Cotton and Evans procedures have typically been taken from the fibula, which heals in over 12-18 months.

    The main issue is where the "breach" is occuring, particularly when observed on a WB lateral film.

    This type of surgery is controversial no doubt, but I have been impressed by the results that I have seen. Certainly best kept for pain unresponsive to conservative care, or *severe* deformity.

    LL
     
  5. Dantastic

    Dantastic Active Member

    What about tactile dysfunction?

    If it is as Eric puts it, "In these kids it is a choice to toe walk", could you encourage short periods of barefoot walking on different surfaces so he gets used to the feeling of putting his heel to the ground?
     
  6. Shane Toohey

    Shane Toohey Active Member

    Hi Rory,

    I'd basically, go along with Eric. Unless there is something extra underlying what has been presented, then I regard toe walking at this age as a strategy developed to avoid a 'weak' foot, i.e. a very pronated foot type. Overlying this now is a very strong habit and soft tissue adaptation. It is important to resolve the toe walking asap to promote growth in the calcaneus which becomes underdeveloped.

    This is what I do:
    Mobilise the feet to free up any blocks. Sometimes the effect is profound.
    Do something straight away to reduce pronation on full weight bearing and add temporary heel lifts to increase loading on the heels.
    Have a dedicated walking session each day with a parent where concentration is on heel contact. Don;t expect the child to walk consciously all day long. They have already learnt to ignore the adults telling them to stop walking on their toes. Included in the walking session is some time walking backwards just to 'break up' that habitual walking pattern.

    I've had good results with this system. Of course, not being a surgeon, I am not inclined in that direction for this problem.

    Cheers
    Shane
     
  7. Rory McFadden

    Rory McFadden Active Member

    Firstly, thanks to all of you for taking the time to reply.I appreciate your input.I agree whole heartedly with the "if it ain't broke dont fix it" advice in relation to surgical intervention.

    Since my initial post I have contacted a paediatric physio who has agreed to carry out an assessment of this young patient along with me.

    Shane
    I would be interested if you could provide me with any information regarding the specific myofascial release techniques you would consider employing on this patient.

    Regards
    Rory
     
  8. Scorpio622

    Scorpio622 Active Member

    If this is purely habitual and the DF range is sufficient for a heel-toe pattern, then try things to force a plantigrade heel (without being torturous). You could try taping his ankles to prevent PF, or place a full length graphite shank to make toe brake impossible.

    I've often wondered if this problem is purely a foot/ankle issue, or is activation of the hip and knee something we should be looking at ??? What if we put these kids in b/l cam-boots to force more hip motion and obviously heel contact. Sounds extreme but nowhere near TALs on healthy tendons. Which makes me wonder: Do TALs work on these kids because of the casting and not the surgery ???????????

    Nick
     
  9. gavw

    gavw Active Member

    Toe walking, thankfully most of the time is indeed harmless, however is is also implicated in a range of neurological conditions. For instance it may represent immature neurological development and is very often seen in conjunction with Autism. Out of interest, is there any developmental delay, or problems with visual perception? Is there any issue with fine or gross motor skills?

    I might venture to suggest that idiopathic toe walking may only be diagnosed when all potential neurological problems have been eliminated.

    I have a paper you might find useful which I'm happy to email to you if you like.

    kind regards

    Gavin Wylie
    Podiatrist, Perth, UK.
     
  10. GarethNZ

    GarethNZ Active Member

    Gavin,

    You have some very vaild points...

    I would be interested in your paper you wrote! my email is

    gazzamilne@hotmail.com

    Do you have anything of interest your trying to find and can't? I have access to journals through a medical school.

    regards,

    Gareth
     
  11. LuckyLisfranc

    LuckyLisfranc Well-Known Member

    Dear all

    Whilst I agree on taking a judicious approach to this problem, there are many young people with *severe* juvenile flexible pes planovalgus, where the main driver of the condition is a severe equinus. I would go as far as saying this it *the* major factor in all of the cases in this class I have cared for.

    The greatest philosophy of podiatric practice I have ever been taught, which sits in my mind like a neon sign with every foot - from a paediatric flatfoot, to a neuropathic Charcot deformity is:

    "The Greast Deforming Force Affecting the Human Foot is an Equinus"

    In this case, and every other case similar to it - should the lateral view show that the calcaneal inclinication angle is approaching negligible, nothing permanent will be achieved until the equinus is addressed (conservatively or surgically).

    Yours, in adecdote.

    LL
     
  12. Rory McFadden

    Rory McFadden Active Member

    Hi Nick / Gavin
    This young guy has hit all his developmental milestones within "normal" time scales and there are no reported problems with visual perception.The hip/knee involvement may be revelant.His hamstrings are very tight and glutes are not great.During gait there is no occasional "heel contact", just forefoot to forefoot
    I am hoping that the planned joint Pod/Physio consultation will prove very beneficial.

    Gavin, I would welcome a copy of the paper you mentioned.

    Cheers
    Rory
     
  13. gavw

    gavw Active Member

    Gareth- Just to keep the record straight, its not a paper I authored. I have emailed it to you. Its a good overview of toewalking.

    Rory- Send me your emaill address and I'll send you the PDF of the paper. If you'd prefer to keep your email private, just private message me.

    I think you'll find the joint physio/pod appointment useful. I do alot of these and I find them a excellent way to further my own skills, as well as being incredibly useful for the patient.

    It may be the best thing for your patient at this stage would be a course of serial casting. Do let me know the outcome.

    Good luck with it all.
     
  14. Shane Toohey

    Shane Toohey Active Member

    Hi Rory,

    You wrote

    I personally use manual therapies as an important part of treatment. As pointed out the probable underlying blockage is an ankle equinus (causing a "weak foot"). I don't regard an equinus as a fixed deformity unless it proves so despite my best efforts. The two main therapies that may be useful are joint mobilisations and myofascial trigger point release. You treat what you find, although I'd be working on the joints first as surprisingly often, what seemed a tight muscle group will lengthen to work with a new joint ROM.

    When working on an equinus it often improves as you work through the foot joints apart from the talocrural itself, including both tib-fib jts, subtalar and midfoot joints. You never really know before which one will make the greatest difference until it happens. I would rarely be doing any dry needling on a ten year old and would not expect muscle tightness to be the underlying cause of the toe walking and only an adaptation. If you toe walk the calf has to be tight and knee used mainly flexed, so tight hammies, as well. Nevertheless, if you do need to work on the muscles I'd suggest looking closely at the peroneals and biceps femoris as well as gastroc.

    Hopefully, this response explains what I mentioned in an earlier posting. I'm happy to elaborate further if you like.

    Cheers
    Shane
     
  15. efuller

    efuller MVP

    I agree the strongest muscle, with the largest lever arm at the ankle joint is the gastroc soleus complex. There will be huge forces and moments coming from this muscle.

    One of the great pearls of wisdom in Normal and Abnormal Function of the Foot by Root, Orien and Weed was that an equinous can cause pronation or supination. They made these observations, but didn't put them in the same place in the book. These observations can be explalined by different positions of the STJ axis. An equinous with a serverely laterally deviated STJ axis will tend to cause supination and an equinous with a severely medially deviated STJ axis will tend to casue pronation.

    That was a very interesting, and plausable, suggested as explanation of toe walking. It could be a stratagy chosen to avoid high pronation moments from the ground. It certainly bears some looking into. It also makes you wonder if getting the kid to walk with his heel on the ground is a good thing.

    Lots to think about,

    Eric
     
  16. LuckyLisfranc

    LuckyLisfranc Well-Known Member

    Eric

    Indeed - I have often pondered when staring at an x-ray why an equino-varus deformity has occurred, when it is equally plausiable that an equino-valgus deformity could have happened.

    ? Is it the STJ axis which determines which way it will go, even before a child takes his/her first steps? :confused:

    LL
     
  17. efuller

    efuller MVP

    That is a big nature/nurture question. When I was little I was severely pigeon toed. My parents told me I had to wear those uncool shoes unless I could walk with my feet pointing forward. I now have a 23 degree metadductus with a medially deviated STJ axis. Prolonged high use of peroneals to pronate my foot could possibly lead to a medially positioned axis in adult hood. After seeing serial casting successfully treat a club foot, it's not a long stretch to apply the concept in other situations. A point for nurture.

    I would bet that there is a range of STJ axis positions in newborns. A point for nature

    Eric Fuller
     
  18. Rory

    A modification which I have used with some success with toe walkers in a boot clinic (podiatrist physio and orthotist) is a carbon fibre base plate in the shoe. This prevents the foot from going up on to the PMA.

    Sometimes works

    Regards
    Robert
     
  19. Very interesting discussion. If the child is asymptomatic, only has a finding of being a toe-walker, and can run and keep up with other children his age, then I would treat with anti-pronation foot orthoses with heel lifts and medial heel skives and not recommend surgery. However, if orthoses do not relieve the symptoms, then I would recommend an Achilles tendon lengthening or gastrocnemius recession and other flatfoot surgical techniques as Tony (LL) recommended.

    When considering equinus, in addition to STJ axis spatial location, one must also consider midtarsal/midfoot dorsiflexion stiffness in the equation. I recently wrote a Precision Intricast newsletter on this topic in which I question the generally held belief in podiatry that equinus always "causes deformities". I believe we need to start considering the load-deformation characteristics of the midtarsal/midfoot joints (i.e. dorsiflexion stiffness of forefoot) when we consider the classification of feet into an equinus deformity and the biomechanics and treatment of equinus.

    In other words, if the forefoot has increased dorsiflexion stiffness, any lack of ankle joint dorsiflexion will tend to produce an early heel off since the forefoot will not be dorsiflexed by GRF acting on the forefoot during late midstance. However, if the forefoot has decreased dorsiflexion stiffness, any lack of ankle joint dorsiflexion will not tend to produce an early heel off since the forefoot will be easily dorsiflexed by GRF acting on the forefoot during late midstance. Therefore, variability in the dorsiflexion stiffness at the midtarsal/midfoot joints may determine how "equinus is compensated" rather than assuming always that "equinus caused the flatfoot deformity".

    Another question that needs to be asked is why does equinus always need to be considered "the major deforming force" that, when seen associated with a flatfoot deformity, is the cause of the flatfoot deformity?? Why not, instead, consider that since the assessment of equinus also includes the inherent assessment of ability of the forefoot to dorsiflex on the rearfoot while the foot is held in the STJ neutral position, that the assessment technique itself tends to overestimate the "equinus deformity". In other words, if a flatfoot that was dorsiflexed with the STJ neutral was found to have only 1 degree of dorsiflexion (and determined as a result to have an "equinus") was now dorsiflexed with the STJ close to maximally pronated position and found to have 10 degrees of dorsiflexion (and determined as a result to not have an "equinus"), then which evaluation more realistically assesses the ability of the plantar foot to dorsiflex relative to the tibia in a foot with this specific deformity?

    We should ask whether STJ neutral position should be used for assessing equinus in a foot that has little practical chance of functioning in STJ neutral position during gait?? Doesn't our current mode of assessing equinus with the STJ in neutral position tend to overestimate the occurence of equinus if this foot will function close to the STJ maximally pronated position during gait. Would the lunge test or a modified lunge test (i.e. performed with the knee extended) be able to determine that a flatfoot with an "equinus deformity" (i.e. measured with the STJ in neutral position) had inadequate ankle joint dorsiflexion...probably not unless the lunge test was performed with the STJ in neutral position.
     
    Last edited: Mar 29, 2007
  20. Beth Gill

    Beth Gill Member

    Hi everyone,
    I know I'm a late-comer to this discussion, but I thought I'd throw in my 5 cents worth.
    I had a similar case last year, with a kid who could stand in static stance with his heels on the floor, but consistently toe-walked.
    I tried stretching and heel lifts and made him up a chart to stand on whilst doing the lunge test, so that he could measure his improvements. But he still toe- walked.
    I ended up putting some 4mm EVA heel lifts into his shoes, but not in the usual position. I put the thick end just proximal to his MTPJ's, with the taper towards his heels. I put them under the insoles of his shoes. The idea was to encourage heel contact by making the heel "lower" in comparison to the forefoot.
    He didn't complain of any discomfort, and 4 weeks later he was actually walking heel-to-toe two thirds of the time. Parents were happy and I haven't seen them since. :)
    I've only tried it once, so not really a RCT, but might be worth a go.

    Thankyou,
    Beth.
     
  21. Rory McFadden

    Rory McFadden Active Member

    Kevin

    Are you suggesting that there may be a direct link between the orientation of the STJ axis and the flexibilty of the midtarsal/midfoot dorsiflexion?

    Regards
    Rory
     
  22. Rory and Colleagues:

    Subtalar joint (STJ) axis spatial location will be determined by many factors. One of these factors is medial column flexibility or, as I prefer to call it, dorsiflexion stiffness of the medial column. With a given ground reaction force (GRF) load on the medial column, a medial column of a foot with a stiffer medial column will dorsiflex less than will the medial column of a foot with a less stiff medial column. As a result, the foot with the decreased medial column stiffness will tend to have more medial column dorsiflexion during weightbearing activities which will then lead to increased STJ pronation motion. Increased STJ pronation motion will cause increased medial translation and internal rotation of the STJ axis relative to the plantar foot.

    Looking at this situation another way, if two feet are compared, and one has a medial STJ axis location and another foot has a normal STJ axis location, the foot with the more medial STJ axis location will have increased STJ pronation moment that will tend to cause the foot to pronate, increasing the GRF plantar to the medial metatarsal heads. This increased GRF plantar to the medial column will increase the tensile force within the plantar fascia and medial column plantar ligaments which will, over time, cause an elongation of these ligaments due to creep phenomenon. Ligamentous creep of the medial column ligaments will decrease medial column dorsiflexion stiffness allowing more pronation to occur and, therefore, more medial STJ axis deviation to occur.

    Therefore, Rory, yes, there is a direct mechanical link of STJ axis spatial location to medial column "flexibility".
     
  23. CraigT

    CraigT Well-Known Member

    This has turned into a very interesting thread.
    When I assess anyone, part of my assessment involves examining dorsiflexion ROM and stiffness in a range of positions- NWB with and without STJ pronated, and WB with and without STJ in the neutral position- I am sure there are many others that do this.
    As a component of this, I like to use a lunge test with the first MTPJ dorsiflexed against the corner and edge of a desk or in a doorway so that the knee can lunge forward past the outside of the foot. This utilises the windlass mechanism to ensure the midfoot doesn't dorsiflex during this motion. This is then compared to a lunge test without the windlass support. The difference in ROM, and effort required to obtain a similar range in both positions can be very revealing (especially to the patient).
    A similar test can be performed with knee extended by using your fist or some kind of block to dorsiflex the first MTPJ, or by getting the patient to maintain a neutral STJ position. You can then compare to the relaxed position.
    I find this very useful in demonstrating to the patient why stretching is important- I generally suggest that they use these positions to stretch out or self mobilise the 'ankle and calf complex'. Patients may feel the restriction in many different places when they do this- often it is not the achilles or calf, but around the joint itself.
    Observing the differing responses to these tests make me wonder if there is a vicious circle going in a lot of these cases- as we know, there is a need for a certain amount of dorsflexion between the foot and the tibia. This is obtained through a combination of ankle and foot dorsiflexion. If you have decreased midfoot dorsiflexion stiffness, then it will be easier to use this to obtain the dorsiflexion ROM necessary, and there will be less tendency for the ankle joint complex to provide dorsiflexion.
    So if the patient is gaining dorsiflexion through decreased midfoot stiffness and midfoot pronation- and they have less requirement for dorsiflexion of the ankle joint- do they then lose flexibility in the ankle joint??? In essence could this lead to a rearfoot equinus?
    If they don't use it, do they lose it??
    While we often blame an equinus as a cause, could it also be an effect? A combination of both?
     
  24. Rory McFadden

    Rory McFadden Active Member

    Kevin
    Nice succinct explanation.Thanks

    Craig
    I like the "chicken and egg" scenario you are "hatching" regarding equinus

    Cheers

    Rory
     
  25. efuller

    efuller MVP

    I agree with Kevin that most of the time a flexible foot will have a medially deviated STJ axis and most of the time a rigid foot will be likely to have a more laterally positioned axis for the reason that he described. However, there are some rare feet that are very flexible and have a laterally deviated STJ axis. The rigid foot with a medially deviated STJ axis is not as rare. I believe axis position and rigidity are somewhat independent. When looking at a population you would see a correlation between axis position and rigidity. However, we don't treat averages, we treat individuals and therefore we should not assume that a flexible foot has a medially deviated STJ axis.

    Regards,

    Eric
     
  26. efuller

    efuller MVP

    I have a problem with the idea that midfoot flexibility will cause an equinous. The reasoning above seems to be saying that if they get the dorsiflexion at the midfoot they will not use the ankle dorsiflexion and therefore loose the ankle dorsiflexion. Again we should look at stiffness to test this idea. The stiffness of the ankle joint is quite variable. In the middle of the range of motion, if there is little tension in the Achilles tendon (from muscle contracture) then the ankle will be very flexible. When the ankle joint dorsiflexes to the point where there is passive tension in the muscles attaching to the Achilles tendon then the ankle joint will be a lot more stiff.

    The same analysis can be applied to the midfoot. In the middle of its range of motion the joint has little stiffness and the stiffness will increase when the plantar ligaments develop tension. So when the ankle joint is in the middle of its range of motion and the forefoot is dorsiflexed on the rearfoot to the point where the plantar ligaments are tight the midfoot will be more rigid than the ankle joint and force applied to the forefoot would tend to dorsiflex the ankle joint over the midfoot in this situation. Of course the above assumes that the individual is not choosing to be a toe walker. Choosing to be a toe walker would require CNS activation of the gastroc and soleus and this would then make the ankle stiffer and then you might see midfoot dorsiflexion depending on how rigid the midfoot was. If the person chooses not to be a toe walker some of the time then the ankle joint motion will be used and an equinous will not develop. On the other hand, if there is spasticity in the muscle, the muscle may contracting 100% of the time and an equinous could develop.

    Cheers,

    Eric
     
  27. Craig:

    I'm sure you meant to say the following: "If you have increased midfoot dorsiflexion stiffness, then it will be easier to use this to obtain the dorsiflexion ROM necessary, and there will be less tendency for the ankle joint complex to provide dorsiflexion."

    The cause versus effect idea of equinus is an old idea, not a new one. Over a quarter century ago, John Weed, DPM, taught us in our Biomechanics courses at CCPM during the early 1980's about accommodative contracture of the gastrocnemius-soleus complex (GSC) that will occur with excessive arch flattenning. However, he tried to differentiate accommodative contracture of the GSC versus congenital GSC contracture. 36 years ago, in the Compendium Sgarlato TE (ed): A Compendium of Podiatric Biomechanics. California College of Podiatric Medicine, San Francisco, 1971.), there is a long discussion of equinus including accommodative contracture of the GSC with flatfoot deformity, osseous equinus and the presence or absence of pronation of the foot with equinus which was called a compensated (flatfoot), partially compensated (normal to low arch foot) or uncompensated (equinovarus foot with plantarflexed first ray) equinus.

    The big difference between what I am saying and what Root, Weed and Sgarlato were saying it that I propose that we should try to identify and use better terminology (i.e. stiffness) and quantify the ankle joint dorsiflexion stiffness and forefoot dorsiflexion stiffness together without necessarily using the Root et al STJ neutral reference frame. In this way, a better understanding of the mechanical interrelationships between the sagittal plane load-deformation characteristics of the ankle and foot will be gained.
     
  28. CraigT

    CraigT Well-Known Member

    Does this not depend on the stiffness, or ROM of the individual joints also?
    A tight gastroch/achilles is only one potential cause of ankle dorsiflexion restriction- Josh Burns alluded to this in the this thread here- http://www.podiatry-arena.com/podiatry-forum/showthread.php?t=3712 -
    I see what you are saying here, but won't there be variability between individuals as to the amount of movement through the midfoot that will occur before the plantar ligaments tighten??
    Maybe an example to explain myself-
    Let's say a person has 5 degrees of dorsiflexion at the midfoot and 5 degrees at the ankle joint. A lunge test shows he does indeed have 10 degrees of dorsiflexion available. This person in question requires 10 degrees of dorsiflexion in order to 'get over' his foot through midstance.
    So what happens if some kind of injury or change occurs whereby the stiffness of the medial longitudinal arch is decreased? Suppose he now has 10 degrees of dorsiflexion through the midfoot- in addition the STJ axis is now more medially deviated in stance.
    Now there is 10 degrees of midfoot dorsiflexion before there is tightening of the plantar ligaments, and stiffening of the foot. The ROM of the ankle has not changed, but it is not required to provide its 5 degrees of dorsiflexion- it is much easier to use the foot- the path of least resistance.
    Now my question is... if this person is not using that 5 degrees, will the ROM of the ankle change over time (or stiffen up??) so that you may find an equinus on examination???
    Awaiting comments- be kind :)
    This is certainly making my brain tick over...
    Cheers
     
  29. CraigT

    CraigT Well-Known Member

    I think we might have some terminology problems again.
    Re read like this-
    'If you have decreased midfoot dorsiflexion stiffness, then it will be easier to use midfoot ROM rather than ankle ROM to obtain the total dorsiflexion ROM necessary. There will be less tendency for the ankle joint complex to provide dorsiflexion.'
    So I wasn't saying what you thought I was trying to say...
    Perhaps in my response to Eric's post, I have made this clearer.
    Sorry Rory if this has dragged off topic :rolleyes:
     
  30. Rory McFadden

    Rory McFadden Active Member

    Craig
    I dont think this discussion has dragged off my original thread.It has indeed become a very thought provoking discussion.What I am now wondering , in terms of presribing orthoses, where is our primary focus? If as in your example a patient's compensation mechanism results in decreased mid foot stiffness and as a direct result loses a certain amount of ankle joint dorsiflexion, do you initially set out to improve midfoot stability,add a small heel raise and advocate a disciplined stretching programme.Then at subsequent reviews move the focus elsewhere??
    I am just thinking that in terms of my 10 year old patient, I want initially to halt/minimise the primary destructive forces.Then aim to create/maintain an enviroment that permits his feet to develop as optimally as possible.

    Regards

    Rory
     
  31. Craig:

    Sorry, I misread your original statement and agree that your original statement makes sense to me now. What was I thinking?!

    Yes, I believe this is the same phenomenon that Root et al described as an accommodative contracture of the gastrocnemius-soleus muscles that leads to an equinus deformity. Muscles that are not placed on stretch on a regular basis will tend to shorten over time.
     
  32. CraigT

    CraigT Well-Known Member

    I think that this is the primary focus. You want to minimise pathological forces including pathological compensation mechanisms.
    For any biomechanical problem, there are likely many factors involved. I feel the biggest error we can make is to not, at very least, consider all these factors.
    You summed it up well I think-
    Although I would have probably also used the term - 'provide an appropriate degree of supination force early on rearfoot loading'-
    Put simply-
    1-decrease the ankle equinus as much as possible (stretching, soft tissue therapy etc)
    2- provide resistance against the pathological forces which are caused by the equinus in a way that does no harm to foot function and is comfortable for the patient. (orthotic with appropriate control, often with a heel lift initially)
    3- On review assess the effectiveness of the plan!
    This is all doing what you said- allowing the foot to develope optimally- I like the word 'optimal'- I use it a lot :D
     
  33. efuller

    efuller MVP

    Eric originally wronte

    I have a problem with the idea that midfoot flexibility will cause an equinous. The reasoning above seems to be saying that if they get the dorsiflexion at the midfoot they will not use the ankle dorsiflexion and therefore loose the ankle dorsiflexion. Again we should look at stiffness to test this idea. The stiffness of the ankle joint is quite variable. In the middle of the range of motion, if there is little tension in the Achilles tendon (from muscle contracture) then the ankle will be very flexible. When the ankle joint dorsiflexes to the point where there is passive tension in the muscles attaching to the Achilles tendon then the ankle joint will be a lot more stiff.
    CraigT responded

    Eric Responds
    I agree that there are several things that can contribute to ankle joint stiffness. However something causes the stiffness of the joint to increase as you go from plantarflexion to dorsiflexion. That something can be substituted in the argument below.

    Eric orignally wrote:

    So when the ankle joint is in the middle of its range of motion and the forefoot is dorsiflexed on the rearfoot to the point where the plantar ligaments are tight the midfoot will be more rigid than the ankle joint and force applied to the forefoot would tend to dorsiflex the ankle joint over the midfoot in this situation.


    I think we start running into a measurement problem when you use the above hypotheticals. When measuring ankle joint dorsiflexion you apply force to the forefoot to dorsiflex the ankle and then look at the angle between the weight bearing surface of the foot and the leg. In this position the forefoot is already maximally dorsiflexed. (Or dorsiflexed until stiff) How do you measure forefoot dorsiflexion independently of ankle dorsiflexion?

    I would certainly agree that there will be variability across individuals in maximum stiffness and the amount of range of motion available with low stiffness. However, the measurement tecnique for ankle range of motion is measuring the midfoot in the position where it has high stiffness in the direction of dorsiflexion.

    Let me restate your question. Look at the sagittal view angle between the plantar surface of the calcaneus and he cuboid. Dorsiflex the fifth metatarsal until you feel the stiffness of the fifth met cuboid joint increase and then measure the angle. Let's say the two lines are parallel. Now an injury occurs to the foot and you perform the same measurement and you see the metatarsal line is 5 degrees dorsiflexed relative to the plantar suface of the cuboid and calcaneus. I think this what you are trying to say above. Let's say that when the ankle joint is dorsiflexed to a point where you feel stiffness the angle between the plantar surface of the calcaneus and cuboid is perpendicular to the leg. So, before the injury, when the leg to the ground measurement (sagittal plane) passes past perpendicular the heel will begin to lift and the forefoot will theoretically pivot about the fifth meatarsal head. After the injury, at the same point in gait the rearfoot will pivot at the distal aspect of the cuboid until the slack of the plantar ligaments is taken up (probably 5 degrees) and then it will pivot about the metatarsal heads. When the foot pivots about the distal end of the cuboid there is still a dorsiflexion moment at the ankle jont from ground reaction force at the distal end of the cuboid. This dorsiflexion moment could prevent an ankle equinous from developing.

    In the above foot that is injured there may be a pain avoidance response where the person refrains from using the gastroc and soleus muscles and in this situation the equinous would not develop because the gastroc and soleus are contracting less and would tend to not develop a contracture.

    Well, that's a lot of arm chair theorizing.

    Eric
     
  34. efuller

    efuller MVP

    I rember being taught flatfoot leads to equinus as well. It was another one of those ideas that I had a hard time accepting the first time that I heard it. I'm not sure that I accept it now.

    Cheers,

    Eric
     
  35. CraigT

    CraigT Well-Known Member

    Eric,
    This is an interesting hypothetical!
    Referring back to what I described earlier-

    Often when doing this test, patients will have a dramatic difference in dorsiflexion, or effort required for the same amount of dorsiflexion, when the 1st MTPJ is dorsiflexed.
    When an individual requires a certain amount of dorsiflexion during gait, then they are surely going to use the mechanism which offers the least amount of resistance.
    This is what I am I am referring to in this hypothetical.
    I may not be understanding you correctly, but I think you are saying that the dorsiflexion moment will still be applied and therefore resist the equinus.
    Do you think it is possible that the application of this dorsiflexion moment could be delayed by the midfoot flexibility? If this is the case, could the firing of the gastroch/soleus stiffening the ankle joint come into the picture?? This would then increase the plantarflexion moment... ?something else to consider.
    Maybe a research project in this..? -please, my well read colleagues, jump in and list previous studies here...
    Cheers
     
  36. Eric:

    I don't have a hard time accepting this idea since it seems to correlate with my clinical observations. I do believe that age has an effect in the sense that it is much more common to see flatfoot in adults associated with equinus than to see flatfoot in children associated with equinus. I commonly see children with pes planovalgus deformity with very large ranges of ankle joint dorsiflexion whereas rarely see adults with pes planovalgus deformity with normal ranges of ankle joint dorsiflexion. We know that muscles will accommodate to a shorter length over time if not stretched regularly. Possibly these accommodative shortenings of muscles require years in some people and only months in others? It makes good sense to me that a plantarflexed rearfoot due to a pes planovalgus deformity over time will cause accommodative shortening of the gastrocnemius-soleus-Achilles tendon complex just as women with a habit of wearing high heeled shoes for most of their lives will develop a limitation in ankle joint dorsiflexion as they age.
     
  37. Part of our problem here in this discussion is that we all need to realize that our current definitions and terminology for ankle joint dorsiflexion and for determining whether an "ankle equinus deformity" is present or not is inherently flawed. We must understand that dorsiflexion of the forefoot on the rearfoot will not only affect our measurement of the kinematics and kinetics of the midtarsal/midfoot, but will also affect our measurement of the kinematics and kinetics of the ankle joint. In other words, when we are saying "ankle joint dorsiflexion", what we are really saying is "midtarsal/midfoot dorsiflexion and ankle joint dorsiflexion".

    In other words, if the midtarsal/midfoot joints have increased dorsiflexion motion or increased dorsiflexion stiffness, then we will measure increased ankle joint dorsiflexion motion and increased ankle joint dorsiflexion stiffness, assuming all other things are equal. If the midtarsal/midfoot joints have decreased dorsiflexion motion or decreased dorsiflexion stiffness, then we will measure decreased ankle joint dorsiflexion motion and decreased ankle joint dorsiflexion stiffness.

    So, as walking gait progresses during midstance, if the midtarsal joint has decreased dorsiflexion stiffness, that lack of forefoot dorsiflexion stiffness will delay the increase in ankle joint dorsiflexion moment that occurs since the intrinsic reduction in forefoot dorsiflexion stiffness will directly affect the transmission of dorsiflexion moments to the ankle joint. In other words, if the plantar forefoot is too flexible to bear the weight from the ground, then ankle joint dorsiflexion moments from ground reaction force (GRF) will be greatly reduced since ankle joint dorsiflexion moments, by definition, require GRFs distal to the ankle joint axis (i.e. plantar to the forefoot) to be present.

    If, however, there is increased forefoot dorsiflexion stiffness, then ankle joint dorsiflexion moments will be rapidly increased as midstance progresses due to the rapid increase in GRF plantar to the forefoot. Therefore, midtarsal/midfoot dorsiflexion stiffness is not only a consideration when determining ankle joint dorsiflexion stiffness but is, by our current definitions, a mechanically important factor that determines ankle joint dorsiflexion stiffness.

    All of these factors I have presented above are also affected by any ankle joint plantarflexion moments and midtarsal/midfoot plantarflexion moments that are caused by contractile activity of the extrinsic and intrinsic muscles of the foot. These are very complex mechanical interrelationships, but certainly, biomechanical analyses, such as the ones provided in these discussions, will lead us all into a better understanding of the function of the bipedal human organism.
     
  38. efuller

    efuller MVP

    Regarding the theory that high midfoot flexibility (low stiffness) leads to contracture of the gastroc soleus compelx.

    I agree with the observation that if you don't use it you will lose it. Now the question is whether or not these people lose their ankle range of motion becuase of a flexible midfoot or some other reason. Perhaps the older folks don't run around as much and avoid pain by not stressing their ankle joint range of motion.

    Good discussion,

    Eric
     
  39. efuller

    efuller MVP

    Lifting the hallux will raise the arch height. As arch height increases the talus will have to dorsiflex to keep the heel on the ground. I beleive Don Green called a cavus foot with limited ankle ROM a pseudo equinus because there was contact of the neck of the talus with the anterior infierior part of the tibia. It was pseudo equinus because the Achilles tendon was not the cause of limited ankle motion. When you raise the arch with the windlass you are creating more of a cavus foot so I would bet that you get a smaller angle (leg to vertical) with your test about 100% of the time.

    However, the windlass activiated in this situation is not a normal situation. The forefoot will tend to be maximally dorsiflexed when weight bearing.

    The moment is not delayed in time, but, as Kevin described, the moment is smaller. The center of pressure under the foot is closer to the ankle joint in the flexible foot. This moment will still tend to dorsiflex the ankle. An ankle equinous will result if the gastroc and soleus have constant activation to create a plantar flexion moment. If the person is able to relax the gastroc and soleus then the ankle joint will dorsiflex in response to the moment from ground reaction force. You are right the activity of the muscles comes into play. You have to examine the moments from all sources. The problem with these theoretical discussions is we cannot necessarily predict the moment from muscle activiation. The muscle is activated by CNS activity and behavior is hard to predict.

    Cheers,
    Eric
     
  40. rockyd

    rockyd Member

    Could a simple AFO work by creating mild dorsi flexion may well encourage subtle soft tissue flexibility and increase ROM.
     
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