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Rocker sole shoe in diabetes may increase risk for falls.

Discussion in 'Diabetic Foot & Wound Management' started by NewsBot, Mar 31, 2009.

  1. NewsBot

    NewsBot The Admin that posts the news.


    Members do not see these Ads. Sign Up.
    Rocker bottom soles alter the postural response to backward translation during stance.
    Albright BC, Woodhull-Smith WM.
    Gait Posture. 2009 Mar 27. [Epub ahead of print]
  2. NewsBot

    NewsBot The Admin that posts the news.

    Improving the design of the curved rocker shoe for people with diabetes
    Jonathan D Chapman
  3. NewsBot

    NewsBot The Admin that posts the news.

    Rocker outsole shoe is not a threat to postural stability in patients with diabetic neuropathy.
    Ghomian B, Kamyab M, Jafari H, Khamseh M, Healy A.
    Prosthet Orthot Int. 2014 Jul 24
  4. Craig Payne

    Craig Payne Moderator

  5. Boots n all

    Boots n all Well-Known Member

    In all the time l have been producing rocker soles for people with Diabetes, l have not had a single report of a fall as a lack of postural instability.

    l guess the question is how are they doing their rocker soles to get that result?

    Most clients with Diabetes and PN, do have a tendency to sway backwards, so any heel rocker needs to be formed as a SACH to avoid this IMO.
  6. NewsBot

    NewsBot The Admin that posts the news.

    This clinical trial was just registered:
    That the Use of a Rigid Rocker Sole Reduces the Recurrence Rate of Diabetic Foot Ulcers in Patients With Peripheral Neuropathy.
  7. Orthofootwear

    Orthofootwear Member

    Hi guys, do you reckon this sole as rocker sole? This is one of the soles we've been using for making diabetic shoes.

    Attached Files:

  8. Boots n all

    Boots n all Well-Known Member

    It doesnt look like a rocker sole at all, but we would need to see the side profile.

    If your doing a rocker sole for a Diabetic, its more about how rigid the sole is and the Last and its toe spring.
    Why are you proving the rocker sole in the first place?
  9. Orthofootwear

    Orthofootwear Member

    Billy, this sole is fairly rigid, and the toe spring is about 14 degree.
    Podiatrists needed rocker sole.

    What about your shoes?
  10. Boots n all

    Boots n all Well-Known Member

    How many degrees? Well our standard Ladies range that we sell has a toe spring of 14 degrees, l wouldnt call that a rocker sole.

    Just measured some of our custom made, 25 to 30 degrees for the toe rocker and slightly more for a heel rocker but its over a short distance.
  11. Orthofootwear

    Orthofootwear Member

    What do the toe rocker sole and heel rocker sole mean for wearers? Does it benefit them? Cheers, David(sorry for calling you Billy in the last posts :) )
  12. Boots n all

    Boots n all Well-Known Member

    A rocker sole for the toe, can mean less force required to move into and through the propulsive phase of gait, reducing the force and movement of the toe's, MPJ's and to a less extent to the Achilles. Its all about the fulcrum.
    Whilst a heel rocker can replace the lost movement at the STJ it can also reduce the speed of the foot from heel strike to midfoot stance.

    All good mate, l have been called worse.
  13. Dr. Steven King

    Dr. Steven King Well-Known Member

    Of course rocker bottom "convex bottom" shoes are more unstable.
    A rocking horse would not work or be as much fun if it was not "unstable" in the sagittal plane.

    Passive Dynamics PD would be hindered-reduced if they did not have a solid-ridged rocker bottom.

    Dr. Tadd McGeer did some great early work on PD.

    Flat footed structures "may" have more stability but at a cost to the passive dynamics.

    If the rocker bottom is not ridged enough then it fails to create a lever.
    Think dutch wooden clogs.

    So what could be simple machine solution to this mechanical problem?

    Add two outriggers to your lever. That's what the Hawaiians did to stabilize their ocean going canoes.

    Add a heel and forefoot leaf spring to the lever to assist with sagittal plane stability and energy efficiency.
    Then add this to diabetic shoes and test it against the standard rocker bottom shoe. Please.

    140- pivot point-axis lever
    160- is a second pivot point-axis that actuates the bending of a flexing spring plate.


    Hoping someone understood this today or someday...
    If you want to understand this better contact me.

    If you would be willing to refute it, please do.
    That is called science.

    A hui hou,
  14. Dr. Steven King

    Dr. Steven King Well-Known Member

  15. Orthofootwear

    Orthofootwear Member

    Thank you for the illustration, so much to learn about shoes, especially orthopedic shoe.
  16. Dr. Steven King

    Dr. Steven King Well-Known Member

    What shoe is NOT orthopedic if it is hooked up to a moving musculoskeletal system that crashes into the earth each step?

    Are your shoes orthotics? Do they change or manipulate your groundings?

    Start making more shoes with carbon fiber mid-soles please so that I may have someone to talk to about them.

    A hui hou,
  17. Orthofootwear

    Orthofootwear Member

    David, afternoon, what do you think of the heel-to-toe rocker?

    Attached Files:

  18. Boots n all

    Boots n all Well-Known Member

    Depends on the client and the condition they have.
    Is it relevant to their needs?
    Will it make them a falls risk?
    Depending on the size and location of the rocker and it's fulcrum, you are reducing the main platform of the sole that they stand on. Looking at your diagram and the vertical lines, the main platform of the sole is now only 1/3 of the entire sole and would be very unstable for many
  19. efuller

    efuller MVP

    Standing is different than walking. Standing, you have to keep your center of mass over your center of pressure. If you don't, you will fall over. Standing is like balancing a pencil on your finger. You have to keep moving your finger (center of pressure) or the pencil will fall over. People use their muscles to change the location of their center of pressure. To demonstrate, stand and lean forward. You will involuntarily contract your gastroc and soleus to shfit the center of pressure toward the ball of your foot. If you lean further forward, most people will start contracting their toe flexors to shift the center of pressure even further forward. Now stand place your hands on a wall and lean forward. With your hands on the wall you can lean forward and keep your weight back on your heel (by contracting your anterior tibial muscle.) So, your ability to keep up right is dependent on how far you can move your center of pressure. When you are standing on the rocker shoe shown in the diagram, when you shift your center of pressure of your foot anterior to the rocker point, the shoe will rock forward. Of course you can prevent your self from falling forward, but now we are talking about walking. So there is a smaller base of support with the rocker tip shoes. It is possible to balance on them, but it is more likely that you would have to take a step to maintain balance.

    Rocker tip shoes have been shown to reduce forefoot pressures and increase heel pressures. These shoes will also decrease the lever arm that ground reaction force will have on the ankle joint, so they theoretically can reduce Achilles tension.

    A heel to toe rocker a show with a gradual curve all along the sole would take a lot of effort to balance on.

  20. Dr. Steven King

    Dr. Steven King Well-Known Member


    Well said Eric.
    The convexity of the surface is not as stable.

    So a solution would be to add poles or outriggers to your rocker shoe-- if you want to increase the area in which the COM may balance above.


    Also using composite footwear systems that "Hold an Edge" helps reduce trips and falls.
    Otherwise downhill skiers would build their skies out of EVA and PU foam like all the Big Foam Running and Diabetic shoe makers currently do...

    35 billion cubic liters of fearsome foam footwear waste per yer per year and growing. Why? When will it end?

    If you want a stable system use stabilizing materials like advanced composites not just cushion materials like EVA.
    Otherwise we would building our bridges out of EVA Foam correct??


    Levers Do Work,

    Trolloin' for Intellects
  21. Orthofootwear

    Orthofootwear Member

    David, thanks for the comment.

    You are right, balance is vital. Whom does this heel-to-toe rocker sole apply to? Forefoot surgery?
    Craftsmanship is what i started to learn recently.

    Take care.
    Talk to you soon.

  22. Orthofootwear

    Orthofootwear Member

    Eric, thanks for the informative comment.

    One more question that I need help from you:what are the differences between orthopedic shoes and comfort shoes? I don't think widths is the answer.

  23. Orthofootwear

    Orthofootwear Member

    Steve, thanks.

    Which material is your favourite for sole-making? PU, OR EVA?

    Talk to you soon.
  24. Dr. Steven King

    Dr. Steven King Well-Known Member

    Aloha Linda,
    Soles should be made of abrasion resistant materials with higher coefficients of friction, like say rubber?

    Old fashioned midsoles made of earth polluting EVA PU foams are currently still used by the Big Foam shoe companies, who also recently followed the example of Crocs and got rid of the rubber outsole all together and just left us glitzy EVA molded bottoms. Less costs= Bigger Profit!

    Seriously how does dumbing down shoes to the level of rubber slippers help better protect our children and other loved ones??

    You do not understand the technology I have offered in this string yet by asking this question, that's ok most folks do not and have not.

    Would you build a tetter totter for your kids out of a sturdy piece of wood or flimsy foam?

    A hui hou,
  25. efuller

    efuller MVP

    The name on the box? I'm not aware of any industry standards for orthopedic or comfort shoes. I would rather walk in running shoes as opposed to a lot of the shoes that are sold as walking shoes. In the U.S., for diabetic shoes, I believe the manufacturer has to get a shoe model certified before Medicare will reimburse for dispensing the shoe. There are some shoes that are not certified that I feel would be better than some that are certified. I don't know who does the certification.

  26. efuller

    efuller MVP

    The Hoka One One, is soft, yet rigid enough that it can still function as a rocker sole.

    I don't understand what claims you are making. Rocker tips are used in insensate feet when you want to to reduce forefoot pressures to prevent ulcers. I don't think your device would work for reducing forefoot pressure. Yes, there is a trade off between forefoot pressure reduction and sagittal plane stability, but the decrease in ulceration is often worth it.

  27. Dr. Steven King

    Dr. Steven King Well-Known Member

    All right this called engagement and i promise to be nice.

    Eric what material would you use to build your child's teeter totter?

    There is a concept in mechanical engineering called H3 or height cubed.
    Whereas if you double the thickness of a material you will cube its strength, (if it is fully bonded like 2x4 vs a 2 inch phone book).

    Example, a piece of 4x4 wood would have the bending strength of a 2x4 cubed.

    Thus if you are using foam, a material with a low modulus of elasticity, you will need ALOT OF FOAM to make it function as a lever.
    Thus you have to build a thicker-higher shoe that just puts more foam in the underland-overfill and lift the user higher off the ground thus making them more unstable on a bed of foam that functions to reduce ground contact peak impulse through cushy lossy impedance, " like walking in soft sand or snow."

    When you use carbon fiber "composites" H3 works in your favor by needing less material (composites have orders of magnitude higher modulus than foam) and thus staying lower to the floor and more likely- off the floor.
    Composites can be made of earth healthy materials like flax and when used in a reactive impedance manor with a spring lever can offer higher degrees of stability and energy efficiency.
    They have higher value for recycling and reuse and also will sink in water so they don't become poisonous fish food in our big blue beautiful oceans.


    Now your comment stating that my rocket ship will not reach the moon is based on the fact that you have never seen it nor driven it correct? Tell our readers the truth please.
    "I don't think your device would work for reducing forefoot pressure. " E.F.

    I am still highly unsure if you fully understand the physics and mechanics yet.

    Build your own pair if you dare.

    A hui hou,
  28. Boots n all

    Boots n all Well-Known Member

    Linda, my two sons and l make custom and modified shoes all day everyday, never have l done a rocker to that extreme. Often the off loading effect and that is what a rocker sole is all about, off loading/reducing forces, is complimented with a custom orthoses so that balance is not compromised.
    We some times see Cam/moon boots in here that have an extreme rocker to one foot, the other foot has a mainstream shoe, which helps to stabilise these clients, but they all complain of lower back pain as they fight to stand still when they stop walking.
    To get the best evidence based outcome we use inshoe pressure mapping system, Fscan, the information from this system shows us where the force's are and we make adjustments accordingly, to the sole fulcrum and or orthoses.
  29. efuller

    efuller MVP

    No, Steve you have not sufficiently explained the physics and mechanics yet. Your diagram was incomplete because you left out many forces. I don't understand how your device would reduce forefoot forces. I've written a paper published in JAPMA that explained how rocker tip shoes work. I understand the physics of rocker tip shoes. Go ahead and explain why you think your device would reduce forefoot forces.

  30. Boots n all

    Boots n all Well-Known Member

    "Rocker tip shoes"
    This is how confusion and miscommunications happen.
    People coining their own phrases. I love reading what you write, but it is a "Rocker toe sole" any shoe can have its sole modified, but it hasnt changed the shoe, just the sole.
  31. Dr. Steven King

    Dr. Steven King Well-Known Member

    Aloha Eric and Boots,

    I understand your confusion.
    The best way to understand the mechanics is to START working with and personally using composite spring plates in YOUR existing shoes.

    Otto Bock and Dr. Jill's have reasonabley priced composite spring plates on their websites.

    At this point I agree with Boots " Rocker Tip Shoes??" Is this a term you are using instead of the "toe spring" modification made to the shoe last to "ramp up" the toes at the end of a shoe. Is there a mechanical difference between the two?

    As a side you will find that the toe spring in shoes obsolete with carbon fiber systems. They steal the ability to bend the springs as much at the MPJs thus losing power and strength and make them difficult to fit inside the shoe. ref U of Calgary research by Dr.Nigg on composites and MPJ strength.

    I will be happy to show you mine if you show me yours. Provide a link to your JAPMA published article or abstract I'll have my hospital librarian get it for me.


    My published article-primer on our US Department of Defense grant results was published in Current Pedorthics - Why Cowgirls Wear High Heel Boots. I'll admit only partial testing was completed " (after Dr. Peter Cavanough past director of the American Diabetes Foot Care council hijacked it for himself and has yet to release their Phase 1 or Phase 2 SBIR DoD testing results!)
    Come on Peter show us your tech please it is meant to save life lives of our fellow Americans.

    Let me know when you have more questions after reading the article. Please.

    If we want to prove you are right and me wrong open up your college's testing lab to us and this innovation, that is science.


    Potential is Action in Limbo.
  32. Boots n all

    Boots n all Well-Known Member

    Toe spring is not relevant to a rocker sole either.
    Toe spring is relevant to the Last.
    The Last design has toe spring and the toe spring of a shoe can not be changed by altering the sole.
    A sole is where you create a Rocker sole.
  33. efuller

    efuller MVP

    No, this is not the best way to understand the mechanics. The best way to understand the mechanics is free body diagram analysis. What you are describing is the best way to feel what the stuff inside the shoe. This is different from understanding.

    What I mean by Rocker tip shoes. These are shoes where the midsole is thick and starting about 65% of shoe length the midsole thickness decreases to a much smaller amount at the anterior end of shoe. The increased thickness will tend to make the shoe more rigid and a high tensile strength board last and outer sole will make it quite rigid. There are several citations in my Rocker paper looking at force reduction in the forefoot.

    Reduction of peak pressure on the forefoot with a rigid rocker-bottom postoperative shoe.
    Fuller E, Schroeder S, Edwards J.
    J Am Podiatr Med Assoc. 2001 Nov-Dec;91(10):501-7.
  34. efuller

    efuller MVP

    Steve, I have a question about figure 3 in your article. You have an arrow representing a 25 Kg force acting at the top of the boot. I'm not sure what your claiming that this does for you. Also, are you aware of Newton's first law. For every action there is an equal and opposite reaction. If the leg is applying a 25 kg force to the shoe, the shoe is applying a 25kg force to the leg. This force is pushing the leg backward. Also, that seems like it would hurt. In the text for that diagram, you seem to be claiming that the posterior to anterior force somehow creates a 50 Kg superior to inferior force from the tip of the shoe on to the ground. How is the direction of the force changed? If you want to claim it is because of rotation of the shoe, you are missing a lot of forces that need to be present to cause the shoe rotation. Your diagram is incomplete.

    Also, when I was talking about the benefits of rocker tip shoes, I was talking about force reduction between the foot and the shoe. Your diagram is looking at shoe versus ground forces.

  35. Dr. Steven King

    Dr. Steven King Well-Known Member

    Aloha David and Eric,

    David in the old days yes you were correct.
    "A sole is where you create a Rocker sole."
    But when you incorporate a composite lever spring it is the MIDSOLE where you create the rocker.
    That is why we do not use EVA or PU mid-sole materials anymore.
    Also why is the toe spring added to the last in the first place? I have asked many many folks in our industry and have not found out a single reason that is supported by clinical research.
    I think it is a continuation of the declining plane-simple machine which is needed for better passive dynamic gait from midstance to toe-ff at the expense of heel contact when the passive dynamics are worsened by asking the unloaded limb to lift up and load on the shoe each step , on average 22mm.

    Would you please do me the favor and watch the "Rocking Video" on this link to our research results?

    Eric you are also correct.
    "No, this is not the best way to understand the mechanics. The best way to understand the mechanics is free body diagram analysis."
    But the best way for you and i to have an open conversation about a new orthotic system is to have us both try it. The proof is in the pudding.

    We are currently completing the sponsored orthotic research (from Ameriflax) on the Finite Element Analysis with Dr. Chad Ulven at North Dakota State U.

    Once the FEA is complete we can add the data to the free body diagram.

    I will admit the FBD becomes a bit tough with this dynamic system though, it just does not sit there like foam.

    A hui hou,

    Waiting for Innovation is an invitation to the status quo.
  36. Boots n all

    Boots n all Well-Known Member

    ? What do you mean in the old days, midsole is still part of the sole.

    Toe spring in a Last does two things.
    In a ladies tradition court shoe, as weight is taken up the thinner sole loose some of the toe spring and tightens the topline of the shoe increasing its grip on the foot, this is why court shoes have more toe spring than normal heel ptiched shoe. For the less flexible sole, Goodyear welt, the sole will not flex well, it needs toe spring so you dont trip over your own toes
  37. efuller

    efuller MVP

    What is your definition of midsole? Do you mean midfoot? My definition of midsole is the part of the shoe between the outersole and the upper that runs the whole length of the shoe.

    A rocker at the midfoot does not reduce force on the forefoot. That is from some of the sites in my rocker shoe paper.

    If you can concisely state the claims that you are making for your product and then describe how the device brings about the effects that you say it does, then we can have an open conversation without me actually wearing the device.

    If you think about where the forces are over time, then the FBD is not that hard. Just take snapshots of different times in gait.
  38. Dr. Steven King

    Dr. Steven King Well-Known Member

    Aloha David and Eric and anyone else that wants to chip in a their few cents worth,

    David, interesting i have not heard this one before but understand and have personally felt this, especially when i first started put flat carbon plates in shoes with foam midsoles.
    " the toe spring and tightens the topline of the shoe increasing its grip on the foot".

    This may tighten the shoe around the toes but does not translate to the grip of the shoe to the ground, that is a function of the force applied, the surface area that force is applied to and the coefficient of friction of the two materials making contact.

    Hey for you students reading this is a good site to review.

    I can understand the reasoning since i play tennis.
    Could I also then claim that a significant cause of ingrown toenails is caused by the toe spring when it tightens the topline of the shoe increasing its grip on the foot ??

    Please please provide a single published research paper to support this assertion, please. For the Love of Science...
    "For the less flexible sole, Goodyear welt, the sole will not flex well, it needs toe spring so you dont trip over your own toes"

    Ok Eric now for your comments.
    "What is your definition of midsole?"
    Can we agree to these definitions?

    I agree with old fashioned foam shoes this is correct.
    "A rocker at the midfoot does not reduce force on the forefoot. That is from some of the sites in my rocker shoe paper."

    Old Fashioned Definition
    1. in or according to styles or types no longer current or common; not modern.
      "an old-fashioned kitchen range"
    North American
    noun: old-fashioned
    1. 1.
      a cocktail consisting chiefly of whiskey, bitters, water, and sugar. May be old fashioned but still is tasty...

    Way Important Concept
    An important concept of using a spring levered orthotic is that the cradle helps transfer that midstance-midfoot load to the spring plate enough that a noticeable reduction of pressure is felt under the metatarsal heads ( thus personally most of my running calluses have disappeared, and my broken 5th metatarsal Jones fracture remains un-rebroken...)
    The stiff cradle is an actuator to help the foot pre-bend and bend the spring plate. Ill admit composite spring plates are hard, harder than concrete so you have to use the cradle arch to help bend the plate.
    This would not work the same without having a lever under the spring providing an excursion area for the spring to move in (as opposed to a regular plastic orthotic on top of a flat spring plate.
    Trust me i tried this first, many times.
    This is the main reason i am adding content to this string.
    This concept is enhanced with the use of a longer lever up the leg such as with a modified carbon fiber Ankle Foot Orthotic, Like a stroke brace.

    As to our claims
    Kingetics LLC “Spring Orthotic Device” Claims
    September 15, 2010

    Materials Claims
    : Advanced Composites (i.e. carbon fiber, Kevlar, fiberglass) with advanced resin systems can be manipulated to increase puncture resistance, blast resistance, heat resistance, electrical resistance or conductivity. Strength to weight ratio is very high.

    Biomechanical Claims:

    1. Increased energy efficiency during gait, utilizing and spring and cantilever orthotic. Energy from impact is stored in the spring plate and is used to assist heel lift. Energy from the plantar flexing forefoot over a pivot crates a simple lever and mechanical advantage to assist heel lift. Energy from the dorsiflexion of the spring plate at the end of the cradle (MPJ/MTJ) assists thrust at toe off. Increased energy efficiency will decrease water and caloric demands.
    2. Stability is increased due to the longer and wider effective foot-ground contact. The force from gait is transferred more proximal (heel) and distal (past toes). The rigidity of composites allows stability of the forefoot over uneven terrain.
    3. Decrease of shearing forces. This occurs when the pressure of the metatarsals is transferred distally and under the spring and rotational moment occurs at this location.
    4. Increased force amplifier effects. The strength to push foot pedals (gas pedals etc.) is increased.

    Medical Claims:

    1. Reduction of Impact Diseases. Decreasing the amplitude of the shock wave/longitudinal wave up the kinetic chain will reduce the onset and effects of this negative energy. This would include i.e. plantar fasciitis, achilles tendonitis, OA, lower back pathologies.
    2. Reduction of Diabetic and Neuropathic pathologies. Decreasing the shearing forces on the forefoot will reduce the onset and effects of ulcers and shear related wounds.
    3. Increased mobility. Utilizing “Spring Orthotic Devices” in conjunction with Ankle Foot Orthotics (AFO), braces, prosthetics, and crutches will increase the effective force to ambulate making the less ambled more ambled…

    A hui hou,

    Life is Where You Awake It
  39. Dr. Steven King

    Dr. Steven King Well-Known Member

    As scientist we are often asked to poke and prod.

    "If you can concisely state the claims that you are making for your product and then describe how the device brings about the effects that you say it does, then we can have an open conversation without me actually wearing the device. "

    Has the past post fulfilled your requests enough for you to take the next step inside of pair of newly fashioned shoes?

    Otherwise you may end up suffering from the dreaded blind wise man disease.

  40. Boots n all

    Boots n all Well-Known Member

    Toe spring does not tighten the area around the toes at all.
    It tightens the topline....the topline is no where near the toes.

    Next time you put your high heels on note how the slip on easily, but when you stand and walk they dont slip at the heel, thats because the topline has tightened, its not the toes that has tightened.

    l cant believe how little you really know about footwear...and l mean the basics.

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