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Shoes for frontal plane instability...

Discussion in 'Biomechanics, Sports and Foot orthoses' started by Scorpio622, Sep 25, 2005.

  1. Scorpio622

    Scorpio622 Active Member


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    What is the best shoe to recommend for individuals with frontal plane instability of the STJ and/or ankle? I have been recommending a tennis shoe over a running shoe with the assumption that the running shoe is designed primarily for sagittal plane function and the tennis shoe is designed for more lateral movements (hence more lateral stability). Any thoughts???
     
  2. Craig Payne

    Craig Payne Moderator

    Articles:
    8
    Hiking boots and/or basketball boots.
     
    Last edited by a moderator: Sep 25, 2005
  3. pgcarter

    pgcarter Well-Known Member

    Having spent 15 yrs fitting boots....I agree with Craig
     
  4. Mark Egan

    Mark Egan Active Member

    What about joggers with medial and lateral flares i.e. dunlop KT26's and an ankle stability program?
     
  5. pgcarter

    pgcarter Well-Known Member

    Yes the increased lever arm length associated with heel flare will probably influence the equilibrium of torques around the ankle....see K Kirby
    but I intuitively and less scientifically believe that an eqilibrium balanced by a flare will be "brittle" because the potential excursions from a central/neutral/stronger position will probably be larger, than a situation where larger excursions are limited by intrinsic/supportive shoe boot structure that is in contact with the ankle/distal shank....which I think is better at improving proprioceptive protective balance functions as well as limiting excessive range.
    Regards Phill Carter
     
  6. Mark Egan

    Mark Egan Active Member

    Phil
    I agree with what you are saying but I have found sometimes that hiking boots and Bball shoes are at times bulky and hot, using a lower jogger with a flare is another option in the cupboard.
    Also what are your thoughts on a ankle stability program as part of a Rx regime?
    Regards
     
  7. pgcarter

    pgcarter Well-Known Member

    Mark
    i go along with the heat thing. I'm a bit of a fan of a wobble board for improved shank strength and ankle/STJ control.
    Regards Phill Carter
     
  8. williac

    williac Active Member

    Had a similar situation with a patient a while ago.
    In a nutshell:

    Ex-AFL footballer (early 80's era where rehab was a beer and a bit of ice). Multiple right lateral ankle sprains (and I mean multiple...20+) - resulted in 'chronic lateral ankle instability'. Surgery approached on two seperate occasions. Nil rehab at the time - hard to believe but true. Back on the park with LA and c/steroids. Very poor proprioceptive feedback. Minimal resistance to lateral translation in the frontal plane. New runners etc.. 'blow out' laterally in approx 4 weeks. Not willing to discuss custom f/wear with lateral flare. Hiking boots (Hi Phil) too hot and heavy. Made UCBL - could/would not tolerate - ended up in bin. Ended up trying a specialised ankle brace (Lleyton Hewitt uses similar) with the lateral aspect reinforced - success at last. Massive improvement. When fashion dictates function (as is often the case) lateral thinking reigns supreme.

    Chris
     
  9. pgcarter

    pgcarter Well-Known Member

    Sounds like one of the major problems may be transverse mid foot instability?.....
    In that vein I have seen a few feet with a "short cuboid"...just can't stop abducting at mid foot...have used an inverted style device with a really large lateral flange to try and stabilize....with some success. My wife has a nifty ankle brace for netball with side struts that is quite low volume...will fit in some shoes that are not granny shoes
    Regards Phill
     
  10. efuller

    efuller MVP

    Stability is a word with multple meanings in podiatry. You can have pronation instability or supination instability of the STJ. It is all related to STJ axis position. Basketball shoes and ankle braces could be good for both. Someone with a laterally positioned STJ axis is more likely to have supination instability. Many surgeries don't address this part of the problem. A lateral flare on the show will put the contact point further lateral to the STJ creating a larger pronation moment and thus decrease the supination instability. A valgus heel and/or forefoot wedge can increase the pronation moment to treat supination instability.

    Eric
     
  11. jbuckridge

    jbuckridge Member

    I would recommend a Brooks Beast sneaker as an off-the-shelf solution for this type of client/patient. While it is a runner; it has the widest footprint--excellent lateral stability. It has a very good rocker bottom sole. The Beast has a great deal of torsion control and a rigid shank. An extended heel counter further controls the rear foot.

    Your friendly neighborhood Certified Pedorthist is on your side and ready to help with these issues--a great adjunct for your patients when we work together and a real time saver for you!

    http://brooksrunning.com/prod.php?p=BSI41154
     
  12. This has been developing into an interesting thread and I would like to offer some thoughts. First of all, like Eric Fuller noted, let's try to define stability and instability relative to the foot.

    Foot Stability: A mechanical property of the foot where it is able to resist rotational or translational motions when it is subjected to external forces.

    Foot Instability:
    A mechanical property of the foot where it is unable to resist rotational or tranlational motions when it is subjected to external forces so that either gait abnormalities or pathologies occur.

    One way to quantify stability would be to use the concept of foot stiffness, relative to movement in one body plane. For example, if you were to take and measure the external load vs deformation applied to the STJ and MTJ for frontal plane motion of the foot relative to the tibia, you would come up with a load vs deformation curve where stiffness could be measured and this could be done both passively, without muscular contraction, or actively, with muscular contraction resisting that motion.

    When an individual walks or does other weightbearing activities in shoes, then the shoe may either make the foot more stable or less stable within the frontal plane, depending on the design characteristics of the shoe. It is important to realize that even a stable foot can become unstable in the wrong shoe and that a very unstable foot can be made to be very stable given the correct shoegear.

    The design characteristics of a shoe that will tend to decrease frontal plane instability of the foot are the following:

    1. High top upper made of relative non-deformable material (high stiffness) with the higher the upper and stiffer the material, the greater the stability. To maximize STJ stability, the upper must be above STJ axis, preferably covering the malleoli.
    2. Decreased sole thickness to decrease height of STJ axis from the weightbearing surface.
    3. Increased sole durometer to decrease medial and/or lateral deformation of sole of shoe (i.e. frontal plane tilting of sole) under weightbearing loads.
    4. Increased medial to lateral width of shoe sole to increase medial/lateral lever arms across STJ axis.
    5. Firm binding of upper to the sole to increase frontal plane stiffness of upper of shoe relative to sole of shoe.

    Tennis shoes, racketsport shoes and fitness shoes tend to have increased frontal plane stability relative to running shoes. The thinner and harder the sole, the better. However, having a high top boot does help also, but as mentioned by others, does not allow for good ventilation of the foot. I have had some patients take their boots and have holes punched into the uppers to increase ventilation which greatly helps decrease the perceived heat of their foot.

    I tend to use ankle braces in low top shoes for many of my athletic patients with STJ/ankle inversion instability. Alternatively, I teach them how to tape their ankles, which is often more effective and comfortable than braces, but more expensive in the long run.

    In any way, one needs to understand the mechanics of the ankle/STJ in order to understand frontal plane instability. As Eric Fuller stated, if you don't know about lateral deviation of the STJ axis, then you are missing out on a significant cause of lateral ankle instability within the population. Maybe Craig Payne can tell us about his study that showed that all of the subjects he tested with asymmetrical ankle instability had decreased supination resistance with his supination resistance apparatus.
     
  13. Scorpio622

    Scorpio622 Active Member

    Thanks for all the good suggestions. The reason why I asked the question in the first place was because of the paradox of treating sinus tarsi syndrome. The typical patient is one that has sprained an ankle (hence prone to future sprains) and pronates excessively. Treatment in my experience is best with a functional orthotic. My concern has always been with the inverted posting for obvious reasons. Prophylactically, I usually add a lateral flair and flange to the device but am unsure if this is doing anything. Thats why I am looking towards the sure for lateral support. Any additional thoughts?

    In reference to using high tops... I feel that this serves only a proprioceptive role and not mechanical support. Several studies back me up on this. One that is really interesting is: <Effect of ankle disk training combined with tactile stimulation to the leg and foot on functional instability of the ankle.
    Am J Sports Med. 2001 Jan-Feb;29(1):25-30.> Here they apply only a one inch strip of tape to the lateral ankle and show proprioceptive improvements.
    I have this article on PDF file. I anyone wants it, drop me an email - DPMPT@hotmail.com, and I'll send it off.

    Thanks for the feedback,
    Nick
     
  14. I believe that most cases of sinus tarsi syndrome are the result of excessive interosseous compression force within the sinus tarsi due to excessive subtalar joint (STJ) pronation moments (Kirby, KA.: Rotational equilibrium across the subtalar joint axis. JAPMA, 79: 1-14, 1989.) In patients with previous history of inversion ankle sprains, there is probably also inflamed scar tissue that is being overcompressed within the sinus tarsi during gait causing the symptoms to occur. In addition to using a medial heel skive for patients with sinus tarsi pain that have possible lateral ankle instability, I will add a forefoot extension of 1/8" korex to the orthosis under either the 2nd-5th metatarsal heads or 4th-5th metatarsal heads to help prevent lateral instability. This generally makes the patient even more comfortable in the sinus tarsi which can probably be explained that this modification allows the foot to resupinate earlier in gait, thereby preventing excessive sinus tarsi compression.

    I strongly disagree. Even though proprioceptive feedback is important, there is no doubt in my mind that the mechanical support of braces, taping and high top shoe gear is not only significant, but probably the main effect of these types of ankle support. When the researchers start doing studies that are able to look at the externally applied moments applied across the STJ-ankle axis with these devices (i.e. kinetics) then they will find the mechanical effects of these types of ankle support. However, as long as they are only looking at kinematics, I tend to doubt that their results will be that significant and, this will result in many continuing to say that "their effects are only proprioceptive".

    This is analogous to what is currently happening in foot orthosis research. For years the researchers were saying that the foot orthoses weren't doing anything since the kinematics didn't change much (of course, they were using premade arch supports and frontal plane wedges and calling them "foot orthotics" also!) Now there are numerous studies showing that the kinetics of the rearfoot are significantly changing with real custom foot orthoses. In fact, two recent unpublished studies on healthy and injured runners by Chris MacLean and coworkers at the University of Massachusetts Biomechanics Laboratory that used foot orthoses (polypropylene, Shore A 65 EVA rearfoot posted, nylon strike plate on rearfoot post, 5 degrees inverted with 2-4 mm medial heel skives) showed significant decreases in maximum rearfoot inversion angle, in rearfoot eversion velocity and in internal ankle inversion moment.

    I believe that once researchers start using the type of foot orthoses that many of us who are well-trained in foot orthosis therapy do use in treating patients [instead of using frontal plane wedges and calling those wedges "orthotics"], that they will not only see changes in rearfoot kinetics but also in rearfoot kinematics. I will be talking about this next week in my lecture "Foot Orthoses: Theory and Research Evidence for their Biomechanical Effects" in Melbourne.

    This then begs the question regarding Benno Nigg's "Preferred Motion Pathway" theory, if foot orthoses are causing a change in not only motion but also in muscle activation of ankle invertors, doesn't this require a significant modification to his theory or even a discarding of the theory??
     
  15. efuller

    efuller MVP

    Sinus tarsi syndrome

    I agree with what Kevin said and would like to add a little more. The lateral instability associated with sinus tarsi syndrome is caused by inhibition of the peroneal muscles. Talliard's article in the 80's documents the inhibition, but attributes it to damaged proprioceptors. I disagree with this explanation. The sinus tarsi hurts becuase the joint is at its end or range of motion. The peroneal muscles will only increase compression of the lateral process of the talus against the floor of the sinus tarsi. So, when the patient walks on uneven terrain and starts to supinate, the peroneals don't contract soon enough to prevent the inversion sprain. Peroneal reaction time has been shown to be increased with people with sinus tarsi pain.

    I would base my orthotic prescription on the location of the STJ axis. If the STJ axis was more laterally deviated I would not add the extensions that Kevin described. If it was less laterally deivaited I would add the modifications that Kevin described. (Assuming no other pathology)

    Eric
     
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