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Foot othoses and cycling

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Old 28th December 2006, 02:27 PM
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Default Cycling and foot orthoses

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Old 28th December 2006, 06:49 PM
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Default Cycling and foot orthoses

I have just finished reading the cyclists "bible" on this (Andy Pruitt's book) and the really scary thing is that only one foot type is recognised and its the rarest one (ie forefoot varus) .... so would hate to think what is really being given to cyclists who go this way.
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Old 28th December 2006, 06:54 PM
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Default Cycling and foot orthoses

Related threads:
Foot position and vasti activation in cycling


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Old 28th December 2006, 10:58 PM
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Default Cycling and foot orthoses

Quote:
Originally Posted by Malkor
Ok so custom footbeds are nothing new... Skiers have been using them for years, but now cyclists are getting in the on action. Being an avid cyclist myself I'm looking for any edge to realign my knees during pedaling. I've tried my lovely orthotics but had limited success. eSoles claim to be able to correct biomechanical defects to produce a more efficient pedaling action... dubious! So this is a call to any Podiatrist who has an opinion on how to realign the seated gait (Taking into account the contact points of the saddle and clipless pedals)! Far too many cyclists damage themselves from poor bike setup and poor pedal/shoe/foot interface and with the need for alternative means of transport... cycling will no doubt have a rise in popularity.
It is generally accepted that if the knee can be made to track straight up and down during cycling, with little medial or lateral migration of the knee, then more efficient cycling mechanics will result. In my experience this can best be accomplished by placing orthoses and/or forefoot wedging into the shoe, adding frontal plane wedges to the cleats, adding shims to the cleats, and adjusting the bike fit. In addition, to other parameters that need to be assessed in the cycling evaluation, STJ axis deviation must be noted. STJ axis location has been experimentally shown to affect the knee joint moments that, in turn, affect medial and lateral knee movement during cycling (Ruby P, Hull ML, Kirby KA, Jenkins DW: The effect of lower-limb anatomy on knee loads during seated cycling. J Biomech, 25 (10): 1195-1207, 1992). I believe that medially deviated STJ axes often result in medial knee migration during the power stroke due to the STJ pronation moments generated by the pedal reaction force during this important part of the pedal cycle.
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Old 29th December 2006, 07:35 AM
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Default Cycling and foot orthoses

dear kevin et al. At last a subject to get on with. like your original poster i too am (was ) a keen cyclist. Have never tried custom orthoses for cycling but please consider.

1) cycling biomechanics vastly different from walking running (forefoot is almost exclusively loaded during pedalling)
2) STJ is tri-planar (the big assume re root etc being already discussed elsewhere) so orthoses may work .I have tried the "body geometry" shoes by Specialised which have a soft EVA contoured footbed plus a posted outsole (must work for everybody then!) these seem ore comfy than most cycling shoes but can't say why. consider then that the "normal" base of gait (5-15cm?) is more narrow that the foot spacing (Called "Q-factor" in cycling parlance i believe) may have some influence on pedalling efficiency (this debate seems to come & go in cycling, like most things). So you may be able to improve your pedalling biomechanincs by altering such factors as bottom bracket axle length, pedal axle length, crank length, also posting between pedal & pedal cleat interface. Lake & Shimano both make cycling footwear with heat mouldable carbon outsoles. rest assured whatever is to be tried will largely be individual to the competitor(s) and v.expensive. i have tried using "lo Q" axle/ pedal set-ups and this FEELS better but not being a competitive cyclist, i couldn't say if it translates to faster times (a few other track & time trial cyclists have these set ups i THINK but if it gives them an edge the're unlikely to shout about it). None of this replaces good physical conditionig of course, & usually becomes apparent when the riding is largely done in single position ( As opposed to road racing over hilly terrain or MTBing where much out the saddle is involved). Best of luck!

Darren.

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Old 29th December 2006, 09:13 AM
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Default Cycling and foot orthoses

Quote:
Originally Posted by darren Chaplin
dear kevin et al. At last a subject to get on with. like your original poster i too am (was ) a keen cyclist. Have never tried custom orthoses for cycling but please consider.

1) cycling biomechanics vastly different from walking running (forefoot is almost exclusively loaded during pedalling)
2) STJ is tri-planar (the big assume re root etc being already discussed elsewhere) so orthoses may work .I have tried the "body geometry" shoes by Specialised which have a soft EVA contoured footbed plus a posted outsole (must work for everybody then!) these seem ore comfy than most cycling shoes but can't say why. consider then that the "normal" base of gait (5-15cm?) is more narrow that the foot spacing (Called "Q-factor" in cycling parlance i believe) may have some influence on pedalling efficiency (this debate seems to come & go in cycling, like most things). So you may be able to improve your pedalling biomechanincs by altering such factors as bottom bracket axle length, pedal axle length, crank length, also posting between pedal & pedal cleat interface. Lake & Shimano both make cycling footwear with heat mouldable carbon outsoles. rest assured whatever is to be tried will largely be individual to the competitor(s) and v.expensive. i have tried using "lo Q" axle/ pedal set-ups and this FEELS better but not being a competitive cyclist, i couldn't say if it translates to faster times (a few other track & time trial cyclists have these set ups i THINK but if it gives them an edge the're unlikely to shout about it). None of this replaces good physical conditionig of course, & usually becomes apparent when the riding is largely done in single position ( As opposed to road racing over hilly terrain or MTBing where much out the saddle is involved). Best of luck!

Darren.
When I teach the podiatry residents and students about cycling biomechanics and treating cyclists, I emphasize that cycling is all about transmitting power from the lower extremity to the bicycle pedal as efficiently as possible, with the least wasted movement within the foot and lower extremity. As such, any motion of the foot and lower extremity that is not occurring with the sagittal plane, is wasted or inefficient motion.

I also emphasize that the perfect human body for cycling would have a hip joint,a knee joint,an ankle joint and metatarsophalangeal joints, but no subtalar or midtarsal/midfoot joints. With this ideal cycling anatomy, the human body could then eliminate unneccessary and unwanted frontal or transverse plane motion of their foot and lower extremity during cycling so that all the force exerted from the muscles of cycling, such as the gluteus maximus, quadriceps and gastroc-soleus, is transmitted directly to the pedal during the power stroke. In this way, I can focus my treatment on eliminating unwanted motion from the cyclists lower extremity so that they can improve their cycling efficiency, speed and endurance and, hopefully, prevent injuries from occurring.

In general, I will only use foot orthoses in cycling if the cyclist's midtarsal/midfoot joints are particularly flexible and showing excessive movement under forefoot loading. In this way, by preventing midtarsal/midfoot motion, the foot will become a more rigid lever, being able to transmit forefoot loads more efficiently to the pedal. If the foot is more rigid, I may use forefoot valgus or varus wedging, instead of foot orthoses, in the shoe or use varus or valgus cleat wedges (i.e. varus or valgus shims placed between the cleat and shoe sole). For plantarflexed first rays, often a simple 2-5 extension with a mild medial arch and heel wedge on on the bike insole is remarkable in straightening out the knee tracking while cycling.

If there is a limb length discrepancy, I will use a shim between the cleat and shoe sole to equalize the limb difference. I may do minor bike fit adjustments also such as saddle height adjustment, but find that most cyclists I see are already set up pretty well on their bikes. We have a huge cycling and triathlon community here in Northern California with many good bike shops in the area that offer bike fitting with fairly good results.
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  #7  
Old 29th December 2006, 11:19 AM
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Default Cycling and foot orthoses

Hi Kevin and all,

Kevin, you said:
"In general, I will only use foot orthoses in cycling if the cyclist's midtarsal/midfoot joints are particularly flexible and showing excessive movement under forefoot loading. In this way, by preventing midtarsal/midfoot motion, the foot will become a more rigid lever, being able to transmit forefoot loads more efficiently to the pedal. If the foot is more rigid, I may use forefoot valgus or varus wedging, instead of foot orthoses, in the shoe or use varus or valgus cleat wedges (i.e. varus or valgus shims placed between the cleat and shoe sole). For plantarflexed first rays, often a simple 2-5 extension with a mild medial arch and heel wedge on on the bike insole is remarkable in straightening out the knee tracking while cycling."

To which I agree entirely.

I don't treat too many cyclists, but have seen a few over the years. One problem dealt with recently (successfully) was a keen cyclist whose mid-tarsal joint on one foot had collapsed somewhat (over a few years).

Orthosis of choice was a rigid polyprop shell with a high med flange and deep heelcup, 4 degrees extrinsic varus heel (to hold the shell in the right position in the shoe) and a rather arbitrary 3 degrees extrinsic FF varus post. This "value" arrived at after trying a couple of other options - 2 degs and 4 degs. Why ? It seemed right for the patient.

Needless to say, the arrival of bike and portable "rolling road" caused great merriment in the hospital - but thats what you have to do for cyclists to ensure the orthosis works ok (IMO).

Regards,
david
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Old 29th December 2006, 06:56 PM
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Default Re: Cycling and foot orthoses

Quote:
Originally Posted by Kevin Kirby
It is generally accepted that if the knee can be made to track straight up and down during cycling, with little medial or lateral migration of the knee, then more efficient cycling mechanics will result. In my experience this can best be accomplished by placing orthoses and/or forefoot wedging into the shoe, adding frontal plane wedges to the cleats, adding shims to the cleats, and adjusting the bike fit. In addition, to other parameters that need to be assessed in the cycling evaluation, STJ axis deviation must be noted. STJ axis location has been experimentally shown to affect the knee joint moments that, in turn, affect medial and lateral knee movement during cycling (Ruby P, Hull ML, Kirby KA, Jenkins DW: The effect of lower-limb anatomy on knee loads during seated cycling. J Biomech, 25 (10): 1195-1207, 1992). I believe that medially deviated STJ axes often result in medial knee migration during the power stroke due to the STJ pronation moments generated by the pedal reaction force during this important part of the pedal cycle.
Hi Kevin,

I've been having a hard time figuring out how STJ pronation moments from the pedal cause medial deviation of the knee during the down stroke. How do you explain it?

I always thought that it was a center of pressure issue. (There was a comment on this thread about Root biomechanics and about how cyclying is very different from walking. Here is where the tissue stress approach shines. You can apply it at times other than walking which is a problem with sagittal plane as well as Root theory.) When the center of pressure on the foot is lateral to the center of pressure at the top of the femur there will be a Valgus moment applied to the tibia and this will tend to cause the medial deviation of the knee. It would probably be worse later in the ride when the hip abductors become fatigued, because they would apply a moment that would pull the knee laterally during the down stroke. This explanation also makes sense in terms of a varus forefoot wedge helping reduce the medial movement of the knee during the down stroke. The varus wedge would tend to shift the center of pressure more medial and lessen the valgus moment on the tibia.

The research article on vasti activation and foot wedging was very interesting. At the conclusion of the abstract it suggested a valgus wedge for reducing patello femoral syndrome. The knee mechanics is complex in cyclying. When I was doing the biomechanics fellowship at CCPM I starting experimenting with wedging in my cycling shoes. I didn't have patello femoral syndrome to begin with, but a valgus wedge caused all kinds of problems. It created a greater pronation moment on the foot and I could not let my foot fully pronate because my medial malleolus would hit the crank. So, I had to hold my foot inverted against a high pronation moment. I also noticed hip abductor pain in addition to my posterior tibial muscle pain at the end of the ride. After removing the wedge I noticed that my knee was much closer to the top tube. This was consistant with force couple idea. Holding foot supianted will shift the center of pressure under the foot more lateral and then to prevent a huge valgus moment I would have to abduct my hip so that the center of my knee was over the center of pressure of the foot.

I ended up with a slight varus wedge as what I liked most and my hip musculature felt the most relaxed.

There are a lot of people who have high maleolar torsion that causes their foot to be abducted in the transverse plane relative to the leg. These people have to do something to keep their medial maleous from hitting the crank. The generic varus wedge may help these people hold their foot supinated with center of pressure under the center of the foot. This stuff is complicated.

Cheers,

Eric
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Old 2nd January 2007, 05:48 PM
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Default Re: Cycling and foot orthoses

Quote:
Originally Posted by efuller
I've been having a hard time figuring out how STJ pronation moments from the pedal cause medial deviation of the knee during the down stroke. How do you explain it?
If the STJ axis is medially deviated relative to the forefoot during cycling, then during the power stroke, when the pedal reaction force is at its greatest magnitude, the STJ pronation moments will also be at their greatest magnitude. Increased STJ pronation moments will tend to cause more STJ pronation motion which, with the forefoot locked into the pedal, will tend to cause adduction of the knee toward the top tube (i.e. internal rotation and adduction at the hip).

This can be demonstrated by standing on your metatarsal heads on the ground, with your knees flexed, then pronating the STJ...the knee should adduct toward the opposite knee. Very little, if any, knee adduction will occur with STJ pronation when the knee is in an extended position since the knee joint is located nearly on the same line between the hip and foot when the knee is extended. However, with the knee flexed, the knee joint is a much larger distance anterior to the line between the hip and the foot, which will cause much greater knee displacements within the transverse and frontal planes than when performing the same maneuver with the knee extended.
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Old 3rd January 2007, 07:43 PM
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Default Re: Cycling and foot orthoses

Quote:
Originally Posted by efuller
The research article on vasti activation and foot wedging was very interesting. At the conclusion of the abstract it suggested a valgus wedge for reducing patello femoral syndrome. The knee mechanics is complex in cyclying. When I was doing the biomechanics fellowship at CCPM I starting experimenting with wedging in my cycling shoes. I didn't have patello femoral syndrome to begin with, but a valgus wedge caused all kinds of problems. It created a greater pronation moment on the foot and I could not let my foot fully pronate because my medial malleolus would hit the crank. So, I had to hold my foot inverted against a high pronation moment. I also noticed hip abductor pain in addition to my posterior tibial muscle pain at the end of the ride. After removing the wedge I noticed that my knee was much closer to the top tube. This was consistant with force couple idea. Holding foot supianted will shift the center of pressure under the foot more lateral and then to prevent a huge valgus moment I would have to abduct my hip so that the center of my knee was over the center of pressure of the foot.

I ended up with a slight varus wedge as what I liked most and my hip musculature felt the most relaxed.

There are a lot of people who have high maleolar torsion that causes their foot to be abducted in the transverse plane relative to the leg. These people have to do something to keep their medial maleous from hitting the crank. The generic varus wedge may help these people hold their foot supinated with center of pressure under the center of the foot. This stuff is complicated.

Cheers,

Eric
Eric:

As you have stated, cycling biomechanics is complex, but certainly no more complex or difficult than understanding walking and running biomechanics. Unfortunately, the percentage of podiatrists that understand cycling biomechanics is probably less than 0.5% since this subject is not demonstrated or covered adequately during podiatry school.

The fit of the cyclist on the bicycle is critical and it is very important that bike fit is optimized before one starts playing with pedal wedging and foot orthoses inside cycling shoes. I like to put cyclists on their own bike on a wind trainer in the office to do evaluations. It is fascinating to see how small adjustments can make huge mechanical differences in knee tracking and overall cycling efficiency.

Bill Sanner, DPM, while he was a biomechanics professor at CCPM (and also an avid cyclist) was doing a lot of cycling stuff when I was a podiatry student and a biomechanics fellow and he is the one that got me started on my interest in treating cyclists. He was the first to show me how to observe the distance from the medial ankle to the crank arm during the end of the power stroke to assess relative changes in STJ rotational position. In 1984, Harry Hlavac, DPM, was also working on his "BioPedal" in Marin County which he eventually patented. The BioPedal is essentially a bike pedal that could be used to support the foot in varus or valgus positions. http://www.freepatentsonline.com/5860330.html
Unfortunately, for Dr. Hlavac's pedal-invention, this was also the time that the clipless pedal systems started to become popular. In addition, cyclists that were knowledgable of physics did not a pedal that weighed any more than it had to since they knew that if you want to improve performance in cycling, and need to add weight somewhere to the bike, you want to add weight preferably to the non-rotating parts of the bicycle. Basically, the popularity of the clipless pedal systems made Dr. Hlavac's relative heavy clip pedal invention less popular, even though I thought it was an interesting idea at the time.

All in all, I see treating cyclists to be a potentially big area for a sports podiatrist that is looking to expand their practice since cyclists think nothing of spending thousands of dollars (pounds, euros) for new frames and new lighter-weight components for their bikes. The problem is finding a podiatrist that knows much about the subject so that they can teach the interested podiatrist how to do cycling evaluations and treatment!!
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Kevin

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Old 4th January 2007, 01:47 PM
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Default Re: Cycling and foot orthoses

Quote:
Originally Posted by Kevin Kirby
If the STJ axis is medially deviated relative to the forefoot during cycling, then during the power stroke, when the pedal reaction force is at its greatest magnitude, the STJ pronation moments will also be at their greatest magnitude. Increased STJ pronation moments will tend to cause more STJ pronation motion which, with the forefoot locked into the pedal, will tend to cause adduction of the knee toward the top tube (i.e. internal rotation and adduction at the hip).

This can be demonstrated by standing on your metatarsal heads on the ground, with your knees flexed, then pronating the STJ...the knee should adduct toward the opposite knee. Very little, if any, knee adduction will occur with STJ pronation when the knee is in an extended position since the knee joint is located nearly on the same line between the hip and foot when the knee is extended. However, with the knee flexed, the knee joint is a much larger distance anterior to the line between the hip and the foot, which will cause much greater knee displacements within the transverse and frontal planes than when performing the same maneuver with the knee extended.

While seated in my chair, with my forefoot touching the ground, and creating a pronation motion of the STJ, I get a medial shift of the inferior portion of the tibia. This motion, if the top of the tibia stayed in the same place would be adduction of the tibia in the frontal plane. (This is the big if in our discussion. What causes or prevents movemnt of the proximal end of the tibia and distal end of the femur.) The motion on the bicyle that we are trying to explain is movement of the top of the tibia toward the top tube of the bicycle. This motion is either an abduction of the tibia in the frontal plane or adduction of the hip. I think we should look for moments acting on the femur and tibia to explain the medial deviation of the knee at the top of the downstroke.

I'm still having difficulty understanding how pronation moments or motions cause frontal plane motion of the tibia. If the foot was fixed in space and the tibia is alowed to move with STJ pronation, there would be lateral deviation of the knee with the down stroke. Yes this motion would be magnified by the distance from the knee to the STJ, but the motion is in the wrong direction.

Regards,

Eric
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Old 4th January 2007, 11:10 PM
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Default Re: Cycling and foot orthoses

Quote:
Originally Posted by efuller
While seated in my chair, with my forefoot touching the ground, and creating a pronation motion of the STJ, I get a medial shift of the inferior portion of the tibia. This motion, if the top of the tibia stayed in the same place would be adduction of the tibia in the frontal plane. (This is the big if in our discussion. What causes or prevents movemnt of the proximal end of the tibia and distal end of the femur.) The motion on the bicyle that we are trying to explain is movement of the top of the tibia toward the top tube of the bicycle. This motion is either an abduction of the tibia in the frontal plane or adduction of the hip. I think we should look for moments acting on the femur and tibia to explain the medial deviation of the knee at the top of the downstroke.

I'm still having difficulty understanding how pronation moments or motions cause frontal plane motion of the tibia. If the foot was fixed in space and the tibia is alowed to move with STJ pronation, there would be lateral deviation of the knee with the down stroke. Yes this motion would be magnified by the distance from the knee to the STJ, but the motion is in the wrong direction.

Regards,

Eric
Eric:

If an individual is in a half squat position and the foot is then pronated, the resultant internal rotation of the tibia is also accompanied by knee adduction. That would be similar to the movement of the knee toward the top tube during bicycling that will occur with STJ pronation during the power stroke. Doesn't that make sense?

I do agree that hip moments are also very important in determining knee joint tracking toward the top tube during cycling but that STJ moments are also important.
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Old 5th January 2007, 09:57 AM
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Default Re: Foot othoses and cycling

I'd be interested to hear people’s views on footwear and cycling and how an orthotic interacts with it. For example, a carbon fibre soled shoe which is extremely inflexible, would i presume, limit foot motion at certain joints. But how would this affect one's choice of orthotic? Could we assume that the more stable and rigid the sole of the cycling shoe the more beneficial the orthotic (providing ht prescription is correct)?

Did that make sense? Sorry i'm in a rush! :)
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Old 5th January 2007, 10:50 PM
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Default Re: Foot othoses and cycling

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Originally Posted by Lance
I'd be interested to hear people’s views on footwear and cycling and how an orthotic interacts with it. For example, a carbon fibre soled shoe which is extremely inflexible, would i presume, limit foot motion at certain joints. But how would this affect one's choice of orthotic? Could we assume that the more stable and rigid the sole of the cycling shoe the more beneficial the orthotic (providing ht prescription is correct)?

Did that make sense? Sorry i'm in a rush! :)
Carbon fiber isn't necessarily more stiff, it just has better stiffness/weight ratio than other cycling shoe sole materials.

Nearly all shoes designed for cycling have stiff soles which will limit metatarsophalangel joint motion. However, a stiff cycling shoe sole has virtually no effect at limiting subtalar joint, midtarsal joint or midfoot joint motion. A rigid orthosis inside a cycling shoe will help limit STJ, MTJ and midfoot joint motion which should help improve cycling efficiency in more flexible feet, when used in combination with the stiff-soled cycling shoe, which is the normal sole construction for cycling shoes.
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Old 3rd August 2009, 05:05 AM
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Default Re: Foot othoses and cycling

I have done a bit of work with cyclists and while not extremely science based I have observed that the functional anatomy of some people does not suit them in conforming to what a bike is trying to make them do. In this regard it is similar to down hill snow skiing, rigid equipment that is desingned to do certain things and not others.
On a bike the idea is to spin the pedals as efficiently as possible as Kevin has said, but not everybodys anatomy wants to make precise circles in a sagital plane at a defined distance apart mounted on two rotating horizontal surfaces. I have found that facilitating an accommodation of anatomical variations allows less wear and tear for individuals who want to ride bikes a lot but don't have anatomy well suited for that job. This is not the same as being the most efficient for race purposes, one is for speed regardless of wear and tear, the other is to minimise wear and tear and if speed or race efficiency is lost a bit then so be it.
I have experienced a fair few miles on bikes myself, with all sorts of knee issues, and have found that Speedplay pedals that have maximum free rotation in a transverse plane at the pedal decreases knee stress, with very little loss of drive.
One other thing about cycling is that as much as possible you are supposed to be dorsiflexed at the ankle, not plantarflexed, because if you work the gastrox/soleal complex too much being smaller muscles they are more prone to fatigue than the larger more proximal muscle groups. And as Kevin has also said, the fit of the bike is very important.
I have used both medial and lateral forefoot wedging and plenty of folks I see have used their regular foot orthoses in cycling shoes to good effect. But is a field that could stand some more research, as so many others.
regards Phill Carter
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Old 12th August 2009, 09:00 PM
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Default Re: Foot othoses and cycling

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Originally Posted by pgcarter View Post
I have found that facilitating an accommodation of anatomical variations allows less wear and tear for individuals who want to ride bikes a lot but don't have anatomy well suited for that job. This is not the same as being the most efficient for race purposes, one is for speed regardless of wear and tear, the other is to minimise wear and tear and if speed or race efficiency is lost a bit then so be it.
Hear Hear! The world of professional cycling is divided not into racers and non-racers but rather by varying degrees of users. Among the cyclists I make orthotics and wedges for are persons who consider themselves racers but may only accumulate 60 miles in a week or less during certain parts of the year. Hardly a professional training schedule you might say, but consider that they often come to me in an off season or on a down-training schedule and their mileage reflects their current load. My recommendation and fabrication technique is based on their current needs which may include less aggressive FF wedging, more flexible materials, and greater pedal float to actually allow for less influence over the STJ, greater medial midfoot excursion at full peak knee extension moment, and knee valgus during peak power stroke angles. (I also move the pedal axis proximal by 5mm but that's another thread)
WHY? Because at reduced loads and distances, (and in the absence of pathology) it's just plain comfortable!
As their distances and workloads increase, I switch them to firmer orthotic materials (carbon fiber), fully corrected wedge angles, stiffer soled shoes (again, CF), tighter degree of float, etc...until they are locked-in to their full training/raceday LE posture.


Quote:
Originally Posted by pgcarter View Post
I have experienced a fair few miles on bikes myself, with all sorts of knee issues, and have found that Speedplay pedals that have maximum free rotation in a transverse plane at the pedal decreases knee stress, with very little loss of drive.
Well, there you go!
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Old 1st June 2010, 02:07 AM
Th3g1ng3r1 Th3g1ng3r1 is offline
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Default Re: Foot othoses and cycling

Dear All,

I thought I'd ask my question in this thread rather than start a new one. I am a former GB track cyclist that has just completed a BSc sports Rehabilitation degree at Middlesex University in the UK. Now that I'm back in the real world, I am looking to do some work with bike fit combined with corrective exercise for injury treatment and prevention. I have been reading with interest all of the cycling related threads on this forum and related journals but I have a question regarding the rationale behind cleat wedges and forefoot insole wedges. Obviously my degree only skimmed the surface of knowledge on the foot so please forgive me if I am asking a stupid question.

As I understand it, a forefoot varus causes the STJ to pronate during the power stroke and therefore the knee to move medially. Therefore, I can understand that putting a forefoot valgus wedge under the insole would support the forefoot and not let it collapse and maintain the STJ in relative neutral. However, wouldn't a valgus wedge under the cleat affect the angle of the entire sole of the shoe? While reducing the collapse of the forefoot, wouldn't in also move the STJ into a degree of supination?

I humbly bow to your superior knowledge in these matters.

Regards,

Ben
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Old 1st June 2010, 09:41 AM
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Default Re: Foot othoses and cycling

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Originally Posted by Th3g1ng3r1 View Post
Dear All,

I thought I'd ask my question in this thread rather than start a new one. I am a former GB track cyclist that has just completed a BSc sports Rehabilitation degree at Middlesex University in the UK. Now that I'm back in the real world, I am looking to do some work with bike fit combined with corrective exercise for injury treatment and prevention. I have been reading with interest all of the cycling related threads on this forum and related journals but I have a question regarding the rationale behind cleat wedges and forefoot insole wedges. Obviously my degree only skimmed the surface of knowledge on the foot so please forgive me if I am asking a stupid question.

As I understand it, a forefoot varus causes the STJ to pronate during the power stroke and therefore the knee to move medially. Therefore, I can understand that putting a forefoot valgus wedge under the insole would support the forefoot and not let it collapse and maintain the STJ in relative neutral. However, wouldn't a valgus wedge under the cleat affect the angle of the entire sole of the shoe? While reducing the collapse of the forefoot, wouldn't in also move the STJ into a degree of supination?

I humbly bow to your superior knowledge in these matters.

Regards,

Ben
Ben,
I suspect you are mixing your valgus / varus terms above. If someone is pronating through the power-stroke, you wouldn't want to put a valgus wedge in either the shoe or cleat as this will increase the pronation moment acting on the foot. If we used a varus wedge under the foot or at the shoe/ cleat interface this will increase supination moment at the STJ whether the wedge is placed just under the forefoot or under the entire shoe. This does not mean that the foot will supinate, only that the supination moment will be increased. Supination of the rearfoot should increase the stability of the midfoot and increase it's dorsiflexion stiffness, this should be a good thing in cycling, unless the cyclist has a peroneal tendonitis etc.
P.S. you don't need to add a wedge between the cleat and the shoe, by adding a number of washers to the medial (crank) side cleat bolt between the cleat and the shoe you can effectively angulate the cleat to the desired angle. It's a bit more difficult with a look system than a shimano SPD, with the look you may have to add washers to the central bolt too. The best way to do this is on a turbo trainer. If knee alignment is key, video from the front and add washers until you achieve the desired alignment, you can always add internal wedging too if required, but unless you use carbon fibre wedges in all likelihood you will reduce the stiffness of the foot/ shoe interface. I paid good money for carbon fibre soles, why would I want to put a layer of EVA between my foot and it? Also look at saddle height/ offset and bike set-up generally, foot pronation and internal knee rotation may be due to the bike geometry. Hope this helps.
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Old 1st June 2010, 01:18 PM
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Default Re: Foot othoses and cycling

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Originally Posted by Th3g1ng3r1 View Post

As I understand it, a forefoot varus causes the STJ to pronate during the power stroke and therefore the knee to move medially. Therefore, I can understand that putting a forefoot valgus wedge under the insole would support the forefoot and not let it collapse and maintain the STJ in relative neutral. However, wouldn't a valgus wedge under the cleat affect the angle of the entire sole of the shoe? While reducing the collapse of the forefoot, wouldn't in also move the STJ into a degree of supination?
I'd agree with Simon on your switching of varus and valgus and with his discussion of knee kinematics.

There is a paradigm in the podiatry profession that believes that position of the STJ is important for midfoot rigidity. Specifically, the theory goes, when the STJ pronates the midfoot becomes a "loose bag of bones." There is no research to back this up. So, STJ position is only important in how the foot hits the pedal and how the medial maleolus misses the crank.

There are feet that are externally rotated relative to the knee joint axis. Also known as external tibial torsion. So, the toes are much more lateral than the ankle as the foot goes around on the pedal and the person has to do something to keep the medial maleolus from hitting the crank when the pedal is near the bottom of its circular path. STJ supination can adduct the foot so that the ankle will miss the crank. When the STJ supinates to get the adduction there is usually some inversion of the forefoot. When there is inversion of the forefoot, it will tend to increase force laterally. (Shift the center of pressure of the foot pedal interface more laterally. This will increase pronation moment from the pedal at the STJ and force the posterior tibial muscle to work harder. When this happens the cyclist will also have to abduct their hip a little more to keep the center of the knee over the center of pressure of the foot. When the center of pressure of the knee is not over the center of pressure of the foot there will be a frontal plane moment on the tibia and the hip musculature will have to work harder to keep the knee over the foot. This force couple is, in my opinion, what causes the motion of the knee tracking seen in the frontal plane as the cyclist pedals.

I don't think that we can measure well enough to predict what angle the pedal should be at. I think it would be best to alter the shoe pedal angle and let the cyclist choose what angle they like the best.

Cheers,

Eric+
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Old 1st June 2010, 11:47 PM
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Default Re: Foot othoses and cycling

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Originally Posted by efuller View Post
There is a paradigm in the podiatry profession that believes that position of the STJ is important for midfoot rigidity. Specifically, the theory goes, when the STJ pronates the midfoot becomes a "loose bag of bones." There is no research to back this up.
Didn't this paper show the relationship between subtalar joint position and midfoot mobility? RD Phillips and RL Phillips: Quantitative analysis of the locking position of the midtarsal joint. J Am Podiatr Med Assoc, Vol. 73, Issue 10, 518-522, October 1, 1983
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Old 2nd June 2010, 02:17 AM
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Default Re: Foot othoses and cycling

Simon and Eric,

Thank you very much for taking the time to reply. I of course did mix up my vares and valgus

Ben
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Old 2nd June 2010, 08:32 AM
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Default Re: Foot othoses and cycling

Quote:
Originally Posted by Th3g1ng3r1 View Post
Dear All,

I thought I'd ask my question in this thread rather than start a new one. I am a former GB track cyclist that has just completed a BSc sports Rehabilitation degree at Middlesex University in the UK. Now that I'm back in the real world, I am looking to do some work with bike fit combined with corrective exercise for injury treatment and prevention. I have been reading with interest all of the cycling related threads on this forum and related journals but I have a question regarding the rationale behind cleat wedges and forefoot insole wedges. Obviously my degree only skimmed the surface of knowledge on the foot so please forgive me if I am asking a stupid question.

As I understand it, a forefoot varus causes the STJ to pronate during the power stroke and therefore the knee to move medially. Therefore, I can understand that putting a forefoot valgus wedge under the insole would support the forefoot and not let it collapse and maintain the STJ in relative neutral. However, wouldn't a valgus wedge under the cleat affect the angle of the entire sole of the shoe? While reducing the collapse of the forefoot, wouldn't in also move the STJ into a degree of supination?

I humbly bow to your superior knowledge in these matters.

Regards,

Ben
Ben:

Both Eric and Simon have given good advice so far. I have been treating cyclists for the past 25 years and have been involved in a few bicycle related biomechanical studies, with one study being published that showed a correlation of subtalar joint axis location to knee joint loads (Ruby P, Hull ML, Kirby KA, Jenkins DW: The effect of lower-limb anatomy on knee loads during seated cycling. J Biomech, 25 (10): 1195-1207, 1992).

My treatment goals during cycling is 1) prevent abnormal forces which may be causing symptoms during cycling and 2) to make the subtalar joint, midtarsal joint and midfoot joints as stiff as possible while still allowing normal ankle joint motion and in order to improve the mechanical efficiency of force transfer from the lower extremity muscles to the metatarsal heads of the foot. These goals guide my treatment of all cyclists.

There are few ways that I manipulate the foot-pedal mechanical interface in order to improve the mechanical efficiency of the cyclist. I may often add lifts between the shoe sole and the cleat in order to equalize limb length differences or will add varus or valgus wedges between the shoe and cleat for frontal plane abnormalities.

Foot orthoses also work well in cycling shoes for those feet that are relatively compliant in the medial arch and demonstrate subtalar joint pronation/medial knee translation toward top tube during the power phase of cycling. If the subtalar joint pronates during the power phase, the knee will move medially toward the top tube in a kind of elliptical pattern (when viewed from in front of the cyclist). By using foot orthoses to increase the stiffness of the foot during the power phase, more "straight up and down" knee kinematics is produced and more efficient force transfer to the pedal is created during cycling.

I may also use in-shoe forefoot wedging such as reverse-Morton's extensions (a type of forefoot valgus wedge) along with varus cleat wedging to not only invert the shoe to the pedal but also evert the forefoot to the shoe in order to stiffen the midtarsal-midfoot complex and further improve the force transfer to the pedal during the power phase. I have also seen some cyclists show a paradoxical supination of the foot with addition of valgus forefoot wedges to the shoe which I have hypothesized is caused by the central nervous system of the cyclist "sensing" that the more supinated position of the foot on the pedal with a valgus forefoot wedge is the most comfortable or metabolically efficient way to transfer force to the pedal during cycling.

Very interesting stuff, this cycling biomechanics. Unfortunately, it is rare to find a podiatrist that knows very much about cycling biomechanics and treating cyclists since this is not normally covered in podiatry school courses.

Hope this helps.
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Old 24th August 2011, 11:26 AM
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Default Re: Foot othoses and cycling

A general query for those prescribing orthoses for cycling shoes;

I'm a podiatrist who never cycled and work in my clinic with a Sports Therapist who has encyclopedic knowledge of bikes and does very proficient cycling analysis. I have tried to explain to him the possible effect of foot mechanics in his cycling analyses. Between us we have had pretty good results, mostly using forefoot wedging within the shoes as discussed on Podiatry Arena.

We have been discussing the possibe benefits of providing casted orthoses at this point and I would appreciate any advice on the practical manufacture. Should the medial arch fill on the positive cast be less than "normal" orthoses. Having experimented with felts etc we have found this to "feel better" presumably to reduce stj and mtj motion in pronated feet.

Lastly, should the distal edge of the orthoses shell finish behind the mtpj as in "normal" orthoses or as I believe ahead of them. If ahead how far ahead.

Thanks in advance.
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Old 24th August 2011, 01:17 PM
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Default Re: Foot othoses and cycling

Lorcan,

I would pay close attention to what Kevin has written here and read his papers STJ Axis Location Rotational Equilibrium Theory Foot Function and Effect of Lower-Limb Anatomy on Knee Loads During Seated Cycling.

When I make an orthosis for a cyclist, much of what goes into determining what that individual needs I have learned here on PA. Pay very close attention to Kevin's comment that "any motion of the foot and lower extremity that is not occurring with the sagittal plane, is wasted or inefficient motion".

I tend to make a sulcus length low volume orthosis with a full length poron/neoprene top cover. Cycling, skating etc. are unique in that the foot is in a perpetual stance phase of gait, hence my suggestion to make the device sulcus length. As Kevin pointed out, forefoot valgus, plantarflexed first rays etc can be addressed as well and if you evaluate the cyclist on the bike you can determine what is most efficacious. At times addressing the cleat/pedal interface is even more beneficial and cost-effective and that is where your training and clinical experience come in.
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Old 24th August 2011, 02:41 PM
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Default Re: Foot othoses and cycling

Quote:
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A general query for those prescribing orthoses for cycling shoes;

I'm a podiatrist who never cycled and work in my clinic with a Sports Therapist who has encyclopedic knowledge of bikes and does very proficient cycling analysis. I have tried to explain to him the possible effect of foot mechanics in his cycling analyses. Between us we have had pretty good results, mostly using forefoot wedging within the shoes as discussed on Podiatry Arena.

We have been discussing the possibe benefits of providing casted orthoses at this point and I would appreciate any advice on the practical manufacture. Should the medial arch fill on the positive cast be less than "normal" orthoses. Having experimented with felts etc we have found this to "feel better" presumably to reduce stj and mtj motion in pronated feet.

Lastly, should the distal edge of the orthoses shell finish behind the mtpj as in "normal" orthoses or as I believe ahead of them. If ahead how far ahead.

Thanks in advance.
I have used both sulcus length and metatarsal neck length polypropylene orthoses for cyclists and I prefer metatarsal neck length orthoses for cyclists. Some may just be a bare polypropylene shell without a rearfoot post and others may be polypropylene shells covered with full length topcovers and with forefoot extensions of korex or EVA. As Dave mentioned, cleat wedging is very effective and if I can simply use a cleat wedge to solve the problem without an orthosis, I will do so. Also shifting the cleats posteriorly on the bike shoe may also help certain problems.
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Old 25th August 2011, 03:00 AM
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Default Re: Foot othoses and cycling

David & Kevin

Many thanks for that useful info. Will apply as advised.

Lorcan
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