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Why are stiff-soled boots preferred when hiking with heavy pack load?

Discussion in 'Biomechanics, Sports and Foot orthoses' started by Asher, Jun 21, 2013.

  1. Asher

    Asher Well-Known Member

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    Hi everyone,

    I was talking to a hiker recently who also works in retail fitting trail shoes and hiking boots. He mentioned that his customers and he himself find stiff-soled boots more comfortable than those with flexibility at the forefoot when hiking with heavy pack loads.

    I had a look at the boots and I couldn't bend them at all at the forefoot, they were rock solid. There was a rocker at the forefoot but nothing more than I see on more standard workboots that do have a flexible forefoot.

    I would have thought the function of the windlass would be an advantage for hiking (walking) with or without extra load.

    Is it that flexible-soled shoes with heavy load cause additional and detrimental tension to the plantarfascia and demand increased muscle work from the propulsive muscles ... and stiff soled shoes (with adequate rocker at the forefoot) reduce this, bringing the increased comfort this hiker explains?

    But if this was the case, you could extrapolate that stiff-soled shoes are better for our obese patients.

    Your thoughts would be appreciated.

  2. efuller

    efuller MVP

    The toe does not need to dorsiflex for the windlass to "work". In some feet just act of weight bearing will dorsiflex the metatarsal enough so that the plantar fascia is palpably tight. You could say that the plantar fascia in this foot is working because the tension in the plantar fascia is creating a plantar flexion moment on the forefoot.

    Some feet don't resupinate in gait. Some of those feet have a functional hallux limitus. Attempting to dorsiflex the hallux in those feet can lead to high 1st MPJ compression loads, high tension in the plantar fascia, or hallux interphalangeal joint hyperextension.

    Depending on the construction of the sole of the boot you could have different effects. If the sole curves upward you could possibly get a cluffy (sp) wedge effect. If the boot had a true rocker (thicker at metatarsal heads than at toes) then you could keep the center of pressure more proximal. Either, or both, of those effects could lead to increased comfort. Our it could just be an old hiker's tale that rigid boots are more comfortable. It also may not be true for all feet. Your mileage may vary.

  3. wdd

    wdd Well-Known Member

    Hi Rebecca,

    You could extrapolate that but remember that almost without exception the obese are members of the 'can walk don't walk' group unlike hikers who are in the 'can walk walk a lot' group.

    When you say that stiff-soled shoes are 'better' for obese in what way would they be 'better'?

  4. Asher

    Asher Well-Known Member

    Sorry Bill, it seems I was not clear. I don't think stiff-soled shoes are better for obese people - I was just trying to point out that it doesn't make sense. Just like how I can't see how stiff-soled shoes can be better when carrying heavy loads.

    But I can see what you're saying Eric. Thanks for the explanation.

  5. wdd

    wdd Well-Known Member

    Hi Rebecca,

    Thanks for the clarification.

    From my own experience of hiking I would agree to an extent. If hiking over rough terrain or in hills or mountains rigid soled shoes seem more comfortable or less uncomfortable but if hiking on a flat (horizontal), even surface, flexible soled shoes, eg trainers, seem more comfortable and less fatiguing.

    My, relatively unconsidered, rationale has been that wearing flexible soled shoes on rough terrain and/or slopes, results in higher pressures being exerted over relatively small areas of the plantar aspect which causes discomfort, and requires more compensatory motion from within the foot, which fatigues the intrinsic and smaller muscles?

    However the level of comfort might be considered as relative levels of discomfort and on flat surfaces, because the plantar pressures are distributed over larger areas and because the need for fatiguing compensatory motion within the foot is reduced, flexible soled shoes become relatively more comfortable.

    The weight of the back pack and resultant changes in weight distribution exaggerates the pressures and increases the rate of fatigue of the intrinsic and smaller muscles to a greater extent.

    It's possibly a rather low level of response but there might be something of value in it.

  6. Andrew Ayres

    Andrew Ayres Active Member

    I've never known a hiking boot that does not bend and cant see why you would want a stiff soled boot for walking.
    There are however mountaineering boots that are do have stiff or rigid soles similar to ski boots. They are designed to have crampons attached to them for winter climbing and walking. Stiffer, rigid boots take more technical crampons designed for harder climbing where the front points of the crampons are used. More flexible boots are used for less extreme stuff, winter walking and scrambling.

    There are stiff summer boots as well but again they are more for mountaineering rather than walking.
  7. Asher

    Asher Well-Known Member

    Thanks Bill,

    Yes, your account below is just what was described to me.

    And this is was the young man's rationale for it. It makes intuitive sense and I can't come up with anything else.

    I can see the relevance of stiff soles at the forefoot when it comes to mountaineering and the use of crampons as Andy suggests. I'm just struggling to bring myself to advocate them for a walking activity due to the relative lack of windlass function, even while keeping in mind what Eric has said.

    With a heavy load behind where your centre of mass would normally be (I realise you would adjust to bring it forward) I would have thought any sagittal plane enhancement like the windlass would be beneficial to energy expenditure. Maybe it is but that's different to foot 'comfort'.

  8. Here are some slides from my "myth busting" lecture on the windlass mechanism (uploaded in 2 parts). Part1:

    Attached Files:

  9. Part 2:

    Attached Files:

  10. Asher

    Asher Well-Known Member

    Thank you Simon, I take your point (I think). So even when there is no extension of the MPJs, the windlass is in fact, still activated. Got it.

    Have I missed something? Is there something here that explains the improved comfort with heavy pack loads?

  11. Rebecca:

    The choice of thicker-soled, more stiff-soled boots with a slight toe rocker angle has been the choice of backpackers for many years, since I started backpacking in the early 1970s, at least. Some of this choice in boot selection probably comes from tradition among backpackers and some of this choice is based on boot performance from a biomechanical aspect. Certainly, however, in the last four decades, boot design and boot construction materials have improved to the point where things have definitely changed within the industry.

    First of all, the thicker, stiffer soles used in many hiking boots are critical when the hiker/backpacker is going to be walking over uneven terrain in order to decrease the magnitudes of discrete plantar pressures that would otherwise occur when walking over a sharp rock or an exposed root when carrying heavier loads in a flexible, thin-soled shoe/boot. I consider this the most important reason to use a thicker, stiffer soled boot sole: prevention of plantar foot injury from discrete increases in pressure on the plantar foot by walking over sharp/hard obstacles. Of course, the risk of this injury will be increased in a heavier individual, in an individual carrying a pack with increased mass or when walking on ;larger, sharper rocks or other obstacles.

    Secondly, typically manufacturers of thicker, stiffer soled boots have learned over the years, by trial and error, that they must increase the rocker angle of the forefoot of the boot with a stiff sole to allow for proper propulsion in the hiker/backpacker, much the same way that boot-brace walking braces also all have rockers built into their soles to allow for more normal propulsion mechanics. Unfortunately, this is not always the case so one must be careful when buying cheaper boots that the shoe sole geometry is properly matched to shoe sole forefoot rocker angle.

    Third, as both Eric and Simon have already stated, I wouldn't be concerned in the least about "proper windlass function" in these types of shoes. Dorsiflexion of the hallux is not even necessary to allow the plantar aponeurosis to perform many of its normal functions during walking. Certainly, a boot with a stiff sole and a rocker angle built into the forefoot of the sole would still allow some hallux dorsiflexion to occur, especially under the loads seen in heavier individuals carrying large packs. In other words, one does not ideally want the boot sole to be totally rigid, but it does not need to flex 70 degrees at the metatarsophalangeal joints to allow "proper windlass function".

    Of course, there will always be some compromise between boot sole stiffness and boot sole flexibility. However, if buying shoes from a knowledgeable hiking boot store, the sales person will hopefully be taking into consideration the intended use of the boot and individual's weight when recommending the proper hiking/backpacking boot. In other words, if one is a lighter weight hiker on a smooth surface then a more flexible-soled boot or shoe would be totally appropriate for this individual, whereas a heavier or heavily laden individual on a rougher surface may find this type of shoe sole to increase the chance of plantar foot injury due to increased magnitudes of discretely pressures to the plantar foot.

    Hope this helps.:drinks
  12. Asher

    Asher Well-Known Member

    Thanks for the thorough explanation Kevin :drinks
  13. Sicknote

    Sicknote Active Member

    Because they last longer.

    It doesn't matter what the load is, hiking boots have always been notoriously stiff soled.
  14. Fraoch

    Fraoch Active Member

    Kevin said it perfectly in his third paragraph. It's all about the required propulsion.

    Easy hiking/walking requires softer soles and sides; a glorified trainer if you wish. The more extreme the gradient and type of "hiking" (i.e. mountaineering.climbing) the stiffer the sole and sides you need. i dont like the use of the word hiking as it denotes many levels of activity. My Mum's version of hiking is a bit different from mine, especially the type of outdoor stuff i used ot get up to in a previous life.

    When carrying large loads you want your boot to do as much "work" for you as possible. Momentum is your friend, you want to keep moving forward and keep your energy expenditure as effective as possible. You learn how to use your inflexible boots on all types of terrain as you go.

    Stiff rocker. Way to go.

  15. manmantis

    manmantis Active Member

    I'll second the comment from Kevin here about "tradition". I see quite a lot of bushwalkers here in Tasmania and I think a lot of assumptions have developed over the years which don't necessarily hold up when tested. And there is scant evidence in this area to support any particular position.

    I read a couple of copies of early "Wild" (Australian bushwalking/wilderness magazine) which had some interesting articles about boot history and footwear choice.

    I recall one article which reproduced a piece on bushwalking boots from the late 19th century. The bootmaker mentioned the importance of a flared sole for ankle stability. There was also a description of the use of sturdy nails for grip (the old hobnailed boot). I don't recall mention of how stiff the sole was, but I'd guess that if nails were being driven into it that it'd have to be fairly sturdy.

    Another article from the late 1980s or early 90s discussed footwear choice with a bushwalker/climber who had been active for many decades. He railed against what he saw as the unnecessary trend for boots to have become higher & heavier. He advocated walking (at least in the Tasmanian wilderness) in much lighter sneakers. Dunlop KT26 were his preferred shoe at the time of the article. His argument was that bushwalkers spent much time worrying about the weight in their packs, but scant time worrying about the load they carried on their feet. In Tasmania you expect your feet to get wet when hiking for more than a day, regardless of the boot you wear, and boots take up a lot of water, becoming heavier still.

    As I'm prone to testing out assumptions I took to trying much lighter bushwalking boots & shoes after reading that last article. I quite often walk the Tasmanian quagmire, bush & mountains in trail sneakers now. These are a good deal lighter than my leather boots, I think my feet are less fatigued and I have yet to notice any sharp rocks. The trade-off is that they don't last anything like as long as my boots. One pair of trail shoes might get me through 2 or 3 week-long expeditions, but no more than that. I also wouldn't dream of wearing them when walking in snow up in the mountains. I can't get my crampons on a trail shoe.

    I'd also mention that trail runners will cover fairly nasty terrain in pretty flimsy shoes. The Overland trail here is an easy-to-moderate multi-day hike, covering Tasmanian mud & getting up to rocky altitude above the tree-line at aroud 1000m. It normally takes 5-6 days for bushwalkers carrying a heavy pack. The annual Cradle Mountain runners do this in a day (record 7hrs 25m) carrying a lot less, and they wear trail shoes. Now there's probably a comparison that could be drawn between the load the feet take with a heavy pack, vs the impact of running. I'm not the man for commenting on that.

    I can see that with a stiffer sole, you need a rocker to assist propulsion in "normal" walking. I suggest that this naturally followed on as soles became stiffer. I don't follow the momentum argument though. I don't get up a lot of momentum climbing rocks or wading through mud and the rocker doesn't help in those instances.

    I'm going to walk the Western Arthurs range here later this year, roughly 7 days, and I'm considering using a pair of Hoka Ones for that. Very flexible, lots of cushioning, definitely not stiff boots. My pack will weigh around 20-25 kilos as it usually does & I'd anticipate being just fine. I will however expect lots of raised eyebrows.

    My guess is that there's a heap of tradition in hiking boot design and people follow what appears to have always worked. In the absence of much evidence one way or the other we're left to formulate our own choices.


    Last edited: Jun 26, 2013
  16. CraigT

    CraigT Well-Known Member

    I did the Kokoda Track in Papua New Guinea in 2005 and I can say that that was the shoe most of the local guides wore.. and flip flops!
    Very muddy and steep terrain.
  17. HansMassage

    HansMassage Active Member

    Concerning the difference with the obese; more of there weight is on the front where as most of the additional weight of the back pack is on the back. Therefore the whole posture shift to keep the weight over the mid foot is different. You could try wearing your pack on the front to get a feel for what shoe wold work best for the obese.
    Hans Albert Quistorff, LMP
    Antalgic Posture Pain Specialist
  18. dhodgkin

    dhodgkin Member

    There's another simple reason why I prefer stiff soled shoes for - specifically - walking up mountains (and not just my sair big toe).

    When you're going uphill up the steep rocky bits, you've often not got much more space for anything but your forefoot. A stiff forefoot to the boot just makes things more efficient and less tiring - you can dig the toe of your boot in and lever youself up with less effort.

  19. gdenbyUK

    gdenbyUK Active Member

    My view is that a hiking boot has three functions to perform when on uneven terrain such as rock or loose shale: 1) to protect the ankle from inversion injuries, hence the high ankle support and a stiff heel cup; 2) to provide grip, hence the large slotted 'trail' grooves in the sole and 3) to protect the plantar aspects of the foot from puncture and pressure injuries, hence its thickness and relative stiffness, with cushioning above. The heavier the pack, the greater the load on the body and feet, and more important the boot's proper functioning becomes.

    A consequence of a stiff sole is a reduction in ankle and metatarsal flexion and therefore heel lift, resulting in dramatically reduced stride length (baby steps!). However, when going up and down steep inclines, this is NOT the priority - you have a shorter stride in any case! Hence stiff soled hiking boots are most appropriate for hilly and uneven terraine (even building sites). Softer soled shoes or boots are acceptable for strolling along more level, more even pathways, with a more regular gait. Hence as indicated above, the shop assistant should ask about their intended purpose and offer a selection of boots or shoes to match. It is still buyer-beware, requiring some prior knowledge of footwear, how it works and the intended activities.
  20. Dr. Steven King

    Dr. Steven King Well-Known Member

    Aloha Asher,

    We should look at the extreams.

    On the one side is stiff like a ski boot or Dutch wooden clog and the other extream is flexible like Crocs (rubber slippers) or the new Belleville Mini-Mil minimalist combat boot.

    Which shoe offers the best puncture resistance to sharp rocks and roots?
    Which shoe offers the best stability when on uneven ground?
    Which shoe offers the leg a better lever arm to climb inclined slopes?
    Which shoe offers an increase in flexion strength under the MPJ to protect the toe from painful jamming especially when the foot is suspended between two rocks?
    Which shoe is lighter? remember for each 100 grams of shoe weight is a loss of 1% energy efficiency.
    Which shoe offers the ability to cantilever over rocks better?
    Which shoe offers better protection of high loading rates that can lead to stress fractures?
    Which shoe do you prefer when hiking?

    If you are looking into advanced boot systems please review our research results for the new advanced composite boot system we developed and tested for the US Department of Defense and Army's Medical Research and Materials Command for grant SBIR A11-109 "Advanced Composite Insoles for the Reduction of Stress Fractures" posted under the MAREN tab at our website www.kingetics.com.


    Co-Principal Investigator SBIR A11-109 "Advanced Composite Insoles for the Reduction of Stress Fractures."

    Here was the grant topic proposal,

    A11-109 TITLE: Advanced Composite Insoles for the Reduction of Stress Fractures

    TECHNOLOGY AREAS: Biomedical

    ACQUISITION PROGRAM: Office of the Principal Assistant for Acquisition

    OBJECTIVE: To develop a composite boot orthotic that will decrease the risk of musculoskeletal overuse injuries and increase ambulatory performance by reducing loading rates, while increasing energy storage and energy return.

    DESCRIPTION: Musculoskeletal injuries of the lower legs are a primary problem in military populations. Injury rates during military training range from 1-16%, and up to 30% in elite infantry units (1). Specific injuries include stress syndrome, muscle sprains, ankle sprains, knee pain, and metatarsal stress fractures (2). Some of the risk factors associated with high injury rates include high running mileage and high amounts of weekly exercise, both examples of movements where an individual is exposed to high repetitive impact forces.

    Footwear selection plays a major role in the injury risk of the musculoskeletal system. Current military boot applications require stiff thick sole and midsole materials to protect from puncture wounds. Heavy rubber and rigid polyurethane foams are used in most military boots. Under impact testing, military footwear (jungle and leather combat boots) has been shown to have less shock-absorbing capabilities than traditional footwear (3). As a result, extra layers of soft foam have been needed in boots as insoles to reduce repetitive impact shock and stress fractures. Although these materials provide some protection against excessive impact, they also increase the weight and height of the footwear. An increase in boot height can have a negative effect on balance and increase peak pressures in sensitive areas of the foot, both which can increase the risk of injury. An increase in boot weight will speed up the onset of fatigue on an individual, again increasing the risk of injury through the increase of inadvertent falls as a result of a Warfighter’s failing to lift their feet to avoid obstacles on an uneven terrain. In summary, the current military boot contains a cushioning system which causes excessive stress on the metatarsal heads, ankle and knee joints. Efforts to mitigate this lack of cushioning increase the weight of the boot (4), which can be correlated to increased fatigue, which can lead to inadvertent falls and more injuries.

    The challenge is to find an innovative solution that will decrease the risk of musculoskeletal overuse injuries and increase ambulatory performance by reducing loading rates, while increasing energy storage and energy return. Advanced lightweight composite materials, such as carbon fibre and Kevlar have proven to protect our vehicles and soldiers as shielding and personal body armour. The objective is to develop and test advanced composite orthotic designs that will reduce loading rates, while increasing energy storage and energy return, all while lowering the overall weight of the footwear.

    PHASE I: Phase I will include multiple concept designs and development of a working orthotic and synergistic “boot housing.” The prototype will be supported with an analysis of the predicted biomechanical performance benefits, such as the reduction of internal load and the increased energy return of the orthotic. Performance considerations for the orthotic should include: 1) outperforming ASTM F2412-05 puncture standards; 2) reducing outsole and midsole weight of combat boots by >10%; 3) reducing injury risk by >10%; 3) a significant decrease in oxygen consumption; 4) be fire retardant; and 5) increase subjective comfort ratings by 10% when compared to traditional combat boot. Phase I will also include a feasibility evaluation that will address practical factors, such as useful life expectancy of the orthotic, and manufacturing costs.

    PHASE II: Finalize Phase I design and perform multiple biomechanical evaluations of the different prototypes, which may result in revisions to the prototype. Specific biomechanical testing will include: 1) muscle activation (EMG); 2) kinetics & kinematics (e.g., joint angles, angular displacements, and moments); 3) pressure distribution; 4) oxygen consumption (VO2); 5) impulse; 6) comfort; and 7) impact testing. Revised prototypes will be further assessed using biomechanical methods for validation and functional effectiveness. A prospective study will also be executed to add credibility to the reduction of injury risk claims. Sourcing solutions for mass production should also be validated in this Phase.

    PHASE III: The end result of Phase-I/Phase-II research efforts will validate applications and further develop synergistic orthotic boot coverings (uppers and soles). The advanced orthotic system and accompanying boot and shoe systems will be integrated into the current service uniforms for the military and paramilitary government entities including all branches of the military, Homeland Security, fire and police departments, and NASA. The commercial applications will continue with incorporation of orthotic technology in prosthetics, braces, and crutch systems used for the treatment of neurologic and diabetic wounds by the Veterans Administration and general public.


    1. Kenton R. Kaufman PhD, Stephanie Brodine MD, and Richard Shaffer PhD. Military training-related injuries: Surveillance, research, and prevention. American Journal of Preventive Medicine. Volume 18, Issue 3, Supplement 1, April 2000, Pages 54-63.

    2. Hinz P, Henningsen A, Matthes G, Jäger B, Ekkernkamp A, Rosenbaum D. Analysis of pressure distribution below the metatarsals with different insoles in combat boots of the German Army for prevention of march fractures. Gait Posture. 2008 Apr;27(3):535-8.

    3. Williams, Karen M. ; Brodine, S. K. ; Shaffer, R. A. ; Hagy, J. ; Kaufman, K. NAVAL HEALTH RESEARCH CENTER SAN DIEGO CA. Biomechanical Properties of Infantry Combat Boot Development. National technical Information Service, US department of Commerce, 1997.

    4. 2000: Stefanyshyn D J; Nigg B M, Energy aspects associated with sport shoes.

    Sportverletzung Sportschaden : Organ der Gesellschaft für Orthopädisch-Traumatologische Sportmedizin 2000;14(3):82-9.

    KEYWORDS: Combat Boots, Advanced Composite Materials, Injury Risk, Energy Return, Biomechanics, Stress Fractures
  21. manmantis

    manmantis Active Member

    The ankle support argument is used a lot. How much do high top boots actually reduce inversion? How high do they have to be, and how tightly laced to achieve any meaningful ankle support? Is this another well-worn assumption? I'd argue that the flare of the sole has a greater bearing on inversion/eversion than the height of the boot. There is a study on basketball shoes which appears to demonstrate that the height of the shoe actually has little bearing on inversion range. I realise that basketball shoes & hiking boots are a world apart, but similar assumptions have been made for basketball shoes for many years. I raise this to illustrate that just because we assume high-top boots provide ankle support doesn't mean they actually do.

    Is the grip on trail running shoes less good at coping with trail conditions than hiking boots? The trail runners here in Tasmania run some pretty uneven & rocky tracks with trail shoes. Or is the tread deep out of necessity because the soles are less flexible?

    My rock climbing days are behind me, but my old shoes are about as flimsy as you can get. Not great for cramming toes into, but fantastic for gaining grip & purchase on rocky cliffs.

    I'd be interested in understanding the relative impact loads in running vs walking with a pack. The weight of the boot being carried is also going to influence fatigue, so a rocker makes a stiff boot more "efficient", but a lighter/flexible shoe surely requires less energy expenditure so gains "efficiency" in another way.

    My n=1 experience seems to illustrate to me that some of these things are taken for granted. Some things are expected if you want to be taken "seriously" as a hiker/bushwalker, and I think this has a fair bearing on the traditional hiking boot design.
  22. gdenbyUK

    gdenbyUK Active Member

    The height of the boot around the ankle is more to do with comfort than support... The padded collar is there to prevent chafing and prevent ingress of dirt and grit. It is the firm heel cup and its attachment to the firm sole, hidden within the construct of the boot, which serves to limit heel inversion (and eversion) injuries. Mid-range trainers use a similar mechanism, with a hard plastic or reinforced leather cup surrounding both sides and the rear of the heel. Given the interaction between the firm sole, the near rigid heel cup and the rear of the foot, there is no cramming of the feet into the boot or really tight lacing required.

    I don't think I am making too many assumptions here. I am simply being a practical observer of gait, foot function and footwear basics. Regrettably I cannot at this instance refer you to research supporting this view. In-shoe pressure measuring devices might be able to research changes to medial and lateral heel pressures, but I can see ethical problems with deliberately attempting to simulate ankle injuries and the boot's prevention of the same.

    I repeat my previous comment - the user and shop assistant must together match to type of boot / shoe / pump with the job it is to perform... I may agree that if you are bush walking on relatively flat terrain, then a more light-weight, flexible for-foot design may be appropriate (so long as it still protects your ankles to a degree). It may depend upon how far into the bush you are walking, whether you're alone and what risk you are prepared to take with an accidental, debilitating ankle injury. Mountain climbers and those on loose shale perhaps tend to be more cautious in protecting their ankles, going for the 'sturdier' more supportive, injury-preventing boot design.
  23. There is no doubt that a boot that extends superior to the subtalar joint (STJ) axis, has an upper of relatively stiff material and is laced firmly around the ankle/distal leg will offer some protection against inversion ankle injury. The real question for each individual who is hiking or backpacking should be how much protection does each individual need from inversion ankle sprain and also, does the added weight, height and heat retention of such a higher-top boot outweigh the benefits offered by such a boot.

    The concept of three point force application for a brace to be functional about a given joint also applies to low-cut shoes and high-top boots. A low cut shoe can not directly alter STJ moment with a bracing effect from its upper across the STJ axis since it does not contact the foot superior to the STJ axis, it only contacts the foot inferior to the STJ axis.

    This does not mean that shoe sole geometry and construction of any shoe or boot can not also alter external STJ moments since shoe soles can be modified to change how ground reaction force is applied to the plantar foot. What this does mean is that any high-topped shoe or boot that has a firm fitting upper contacting the malleoli, or more superior on the leg, can offer quite substantial bracing effect to the STJ by causing external STJ pronation moments when the foot attempts to over-supinate and by causing an external STJ supination moments when the foot attempts to over-pronate. The high-top boot performs this function by supporting the ankle superior to the STJ axis, which is a function that low-cut shoes simply can't perform since they do not extend superior to the STJ axis.

    Here is an illustration showing this affect in the treatment of posterior tibial tendon dysfunction.
  24. efuller

    efuller MVP

    An observation: When you wear high tops it is harder to use your posterior tibial muscles to invert your foot when in the shoe as opposed to when in low top shoes. This feeling of resistance is a pronation moment that occurs when the STJ is in a more supinated position. So, the shoe is doing something to reduce the effect on the inversion moment from the ground that occurs when the foot has inverted to the point when the entire weight bearing area of the foot is medial to the STJ axis. So, if you have a study that shows that there is no reduction of incidence of inversion injury with high tops, you have to ask the question of whether or not the hightops reduced the severity of the injury. They should as they should attempt to decelerate the joint before the ligaments do. It is a research question that will be hard to answer for a long time, because it is difficult to measure the severity of an ankle sprain.

    There is also what is questionably called the proprioceptive effect. As the STJ inverts, the high top shoes will create some skin sensations that may lead to an earlier peroneal reflex. It is an interesting theory.

    I would agree that a shoe/brace that goes higher will work better than a low top, but I would not go so far as to say that a low top cannot apply moments around the STJ in other ways than by shifting the location of the center of pressure of ground reaction force. You only need two forces to create a force couple that will create a moment. So, the shoe can create a supination moment by applying a lateral to medial force at the lateral heel and a medial to lateral force at the talar head. As the talar head adducts, it will apply a force to the shoe. The low top show will deform with much less force so it cannot resist that motion as well as a high top, but it will still resist that motion. (Think about lacing changes)

  25. What should also be borne in mind here is that a significant amount of frontal plane motion occurs between the tibia and the talus; it's not all about the subtalar joint when it comes to supra-malleolar footwear.

    I'd also say that the reason walking boots traditionally had a high toe spring was because they were high top boots, laced in tight around the ankle and limited sagittal plane motion of the ankle- hence the need for the rocker action in the rigid soles of these boots.
  26. Good points, Eric. I agree.
  27. Which then begs the question: When the calcaneus inverts and everts, how much of that motion is coming from the talo-calcaneal articulation and how much from the tibio-talar articulation? My guess is, in most instances with average ranges of subtalar joint motion, that over 90% of the motion is from the subtalar joint and less than 10% is from the ankle joint (i.e. medial-lateral tilting of talus relative to the tibia in the ankle joint, assuming the ankle joint is not plantarflexing or dorsiflexing at the time).

    It must also be emphasized that more calcaneal inversion relative to the tibia occurs with ankle joint plantarflexion and more calcaneal eversion occurs with ankle joint dorsiflexion, due to the triplane, pronation-supination axis orientation of the ankle joint. These factors certainly complicate any motion analysis study where it might otherwise be assumed that the subtalar joint is the sole contributor to calcaneal inversion/eversion during gait.
  28. Dr. Steven King

    Dr. Steven King Well-Known Member


    These are interesting comments and may offer an explaination for why we use boots and shoes that stabilize the rearfoot but it does not answer the question of this thread.

    Why are stiff-soled boots preferred when hiking with heavy pack load?

    Lets try to keep on track please,

  29. I'm not sure that this is what the bone pin studies seem to be suggesting.
  30. What do the bone pin studies suggest then?
  31. http://www.jfootankleres.com/content/2/1/18

    "A key finding is the considerable freedom of movement that exists at the ankle. For the frontal and transverse planes, respectively, Lundgren et al [26] reported a mean total range of motion of 8.1° and 7.9° during walking (n = 5) (figure 1), Arndt et al [27] reported 12.2° and 8.7° in slow running (n = 4), and using a dynamic cadaver model of stance, Nester et al [9] reported a mean of 15.3°, and 10.0° (n = 13). Whilst in almost all cases the range of sagittal plane motion was greater, the ankle is certainly not limited to the role of a dorsi- and plantarflexion provider, as was traditionally thought.

    Furthermore, there is clear evidence that in some feet the ankle displays more frontal and transverse plane motion than the subtalar joint, which was traditionally perceived as the rearfoot joint most able to move in these planes. In the case of transverse plane motion, Lundgren et al [26] reported that the total range of ankle motion was greater than the equivalent subtalar motion in 3 of 4 participants (in walking). Nester et al [9] reported greater transverse plane ankle motion compared to subtalar motion in 7 of 11 cadaver feet, and Arndt et al [27] reported the same in all 3 of their participants (in slow running). In the case of frontal plane motion, Arndt et al [27] found ankle motion to be greater than the equivalent frontal plane subtalar motion in 2 of 3 participants for which data was available (slow running). Lundgren reported the same in 1 of 4 participants in walking [26] as did Nester et al [9] in 8 of 11 cadavers. Based on these data, the subtalar joint is certainly not the sole 'torque converter' described in many texts, and in fact the ankle and subtalar jonts share this function, with each adopting different roles for different individuals.

    The inter-subject difference in how the ankle and subtalar joints move is also evident in the pattern of movement during stance. Lundgren et al's [26] subject-specific data illustrates that some people display adduction of the talus at the ankle (5–10°) in the first 20% of stance, with other participants showing little motion at all (figure 1). Similarly in slow running [27], 2 of 4 participants showed eversion of the talus at the ankle (> 10° in first 40% of stance), the other two showing little motion at all over the same period. The variation between subjects in the frontal and transverse plane 'role' of the ankle and subtalar joints suggests they could work in tandem to provide the motion required for each person. Certainly, we should never prescribe distinctive roles to these two joints as has been the case (ankle = sagittal plane, subtalar = torque converter) and we might consider them to have quite similar functional roles in the frontal and transverse planes."
  32. So, with these studies in mind, and in your opinion, Simon, during walking, and we see the calcaneus evert to the leg, what percentage of this frontal plane calcaneal to tibial motion is coming from the subtalar joint, and what percentage is coming from motion at the ankle joint?
  33. Rob Kidd

    Rob Kidd Well-Known Member

    Have you both stopped to consider an absolute? One can only attach crampons onto a stiff soled boot.............. In my climbing days this was taken as read
  34. Kevin, the key findings of these studies is the inter-subject variation. I suspect within the larger population we might reasonably hypothesise that continuous variation is exhibited in the ratio of tibio-talar to subtalar joint motion in rearfoot eversion. Thus, in some people when the calcaneus everts to the leg, 100% of this motion will be talo-tibial motion with 0% subtalar motion, in other individuals when the calcaneus everts to the leg 0% of this motion will be talo-tibial and 100% will be subtalar joint motion. If we follow this hypothesis to it's logical conclusion then we should expect our continuous variable to display a normal distribution, given this, I should expect a 50:50 ratio to be the mean within the population.

    Rob, yes I've done a fair amount of mountaineering myself, yet the boots I wear for hiking vary depending upon the terrain and the conditions. One doesn't always need to attach crampons. As someone else suggested earlier, there is a big difference between hiking in the desert and hiking in the Alps. Similarly, footwear design and materials have moved forward too. When I see the old school climbers with their hobnail boots and hemp ropes I'm amazed at what they actually managed to scale.
  35. I would tend to doubt that in normal walking that 50% of the calcaneal eversion is coming from a frontal plane rocking of the talus on the tibia. My guess is that the mean within the population is such that subtalar joint motion is far greater than the calcaneal motion that would come from frontal plane rocking of the talus on the tibia within the ankle joint.

    What percentage of your patients do you think have 100% of their calcaneal motion coming from frontal plane rocking of the talus on the tibia and 0% coming from subtalar joint motion? In my patients?....only those with subtalar joint fusions.
  36. Yes the number individuals with 100% of one or the other will be small- these figures will be at very extremes of the normal distribution curve. You could calculate the exact numbers you'd expect given the global population and the characteristics of the normal distribution curve. However, given the variance already observed in the relatively small samples, I think it's a reasonable hypothesis that we should likely observe continuous variation in this variable within a global sample. As such I stand by my contention that the mean is likely to be around 50:50 in the population as a whole, until proven otherwise.

    The problem is Kevin, clinically we have no idea of the relative contributions since we have no way of measuring it. As you said, you're guessing; I'm attempting to apply statistical theory. :drinks
  37. I'm guessing?.....what else is new?:cool:;)
  38. Don't lose too much sleep, I'd say your speculation rate has been pretty good over the years. :empathy::drinks

    However, if we look at the data we do have from the Nester report, the majority of individuals tested and reported on actually showed greater frontal plane motion at the tibio-talar articulation than at the subtalar joint= 11/18 which appears to question your guess work here. If we ignore the cadaver data and only look at the in-vivo data we get 3/7. Like I said, I'd expect about 50% of the data to be lying either side of the mean (with subjects using one joint more than the other in either direction: tibio-talar or subtalar) in a normally distributed variable. The best (and only) data we have to date, while limited in sample size, seems to support this contention.

    Anyway, we digress... back to hiking boots. We could split this off if anyone wishes to continue with this side discussion, Craig.
  39. blinda

    blinda MVP

  40. I'm having difficulty believing that the talus is rocking in the frontal plane within the ankle mortise by that much. I don't have the time now to look at Nester's paper. Could this frontal plane motion of talus relative to the tibia be due rather to the pronation-supination axis of the ankle joint, instead of a frontal plane rocking that causes incongruity of the superior surface of the talus and inferior surface of the tibia? Are we talking about the same thing?

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