in lay men's terms?

fstshrk...where did you order your Pearl Izumi adjustable insoles from?
Thanks

Forget translating his bio-mechanical take which is believe is patently false throughout...e.g.:
Cyclists should not be predisposed to injuries/conditions due to hyperpronation/hypersupination (flat arch and high arch respectively) because that mechanism exists as a "shock absorber" in walking and running.
Above flies in the face of all convention when it comes to pedal stroke and fit and the thousands of cyclists that have resolved knee issues through their feet. As discussed, cycling isn't anything like walking or running biomechanically. I know many athletes who couldn't survive without custom orthotics and even alleviates foot pain in their dress shoes.
Anatomy of feet varies greatly.

Having the arch supported to prevent pronation is critical to knee health. Arches that collapse (for those with flexible feet in particular) during pressure to the pedals, causes the knee to skew inward and places pressure on the medial ligament which by repetition can be inflamed and injured over time. This is widely known among even average fitters. So adequate support of the foot is key to a good pedal stroke and avoid knee issues in particular.

My intention wasn't to debate biomechanics. Its really irrelevant as the jury isn't out on cause and effect as much as many would like to take issue with it. Point is general discussion about footbed or insole options. Thanks.

To chime in, I started using the PI 1:1 insole system last month as one of several measures to help correct a knee issue. I really like the customizable (varus and arch) insert feature, and I would think barring a fairly severe correctional problem most people should be able to dial in a good fit. So far so good, and miles better than the stock Sidi insert I was using. I got mine from Zappos.

If you have an arch that collapses, then you need an insole with an arch support to avoid over pronation.

However ,if you have no arch whatsoever (anatomically flat), then you don't need an insole with an arch, because forcing an arch into a foot that doesn't have one can be painful. Instead, a flatter insole shape with the correct angle is needed to counteract over pronation... essentially the same as the varus wedges.

I had custom cycling orthotics made for my specialized shoes... created by a podiatrist who is also a pro fitter and Cat 2 racer. His $200 custom orthotics were 80% covered by my insurance at that time. It's worth looking into if you have good coverage.

For one, my post (and others) was about FOOT pain not knee pain. I (and many therapists) will stand by what I said. This is not to say proper foot mechanics are not important, but the issue is far more complex than a simple insole.

And actually, the jury is quite out on cause, effect, and what kind of pathomechanics cause what kind of conditions in what kind of athletes.* The "knee going inward" (valgus collapse) can be caused by a variety of factors and yes flat feet can be one of them, but weak muscles that move your leg away from the midline (abductors) are much more commonly at fault. People with wide hips, particularly women, are at much higher risk for these injuries because those muscles have to work harder and essentially "give up" allowing instability in the knee.

Campag4life, you should know what you're talking about before you call me "patently wrong"

*If you are really interested look up some of Gary Gray's new rehab and exercise techniques.

F4rrest, you are right on.

I have quite well formed arches and I've never had the need for any sort of special insoles or additonal support in any shoes. That is, until I got some actual cycling shoes.

I don't get arch pain in cycling shoes, but I do get nasty numbness and ocassional hot spots, even with suitably wide shoes, even with cleats beind the ball of the foot, with extremely stiff soles and with not so extremely stiff ones. I went for aftermarket insoles with metatarsal pads initially, no extreme arch support, and they do help but they don't fit in my new shoes. I decided to try out Specialized since they also include metatarsal pads and to try out the additional arch support, why not.

Bottomline, from personal experience, feet simply don't function the same when cycling as they do when walking/running.

For months, I was having problems with hot spots under my big toe and a chronic "my feet feel like they are on fire" feeling after rides with lots of climbing. It was not fun at all. I tried different insoles, moving my cleats around, etc. Nothing worked.

So I took my blue inserts to a podiatrist (who is also a cyclist) and he took a look at my feet and taped them up further.

Do not try this yourself without seeing someone who knows what they are doing. It looks unorthodox and when I initially left his office, I thought that he was nuts and that it would never work. To my surprise, it has worked perfectly and I haven't had any problems since. Been back 2 more times to have other sets of insoles taped up in the same fashion (for my CX bike and MTB).

It cost me $30 to see the podiatrist and that was some of the best money I've ever spent!

Bob

Don't have read about it. Skiers and cyclists have known about the benefit of a properly supported foot...longitudinal and transverse arches for decades.

Not laughing at all. Excellent post. As somebody who hung around pro skiing a bit, skiiers constantly fiddled with their boots and foot beds to get just the right level of pressure across the bottom of the foot for the best edge control. Seen it many times on so called 'custom made' footbeds.
Thanks.

Stellar grammar.

All you have. Please don't denigrate this thread further with your blather. Seriously. It insults the intelligence of all the people that benefit by proper foot support...feet being as unique as fingerprints.
Start your own thread espousing your ill founded esoteric theories...maybe as an addendum to Steve Hogg's thread...coined Hogg wash by one poster...still laughing..
Thanks.

In no way am I trying to contradict anyone's opinions when make this observation, just asking for an explanation from those that have some knowledge and experience with this. I can see how a fully or mostly flat arch causes the foot to pronate whether there is weight (force) on the arch or not. The foot simply slopes down toward the inside because it is not lifted by an arch structure: automatic pronation. But suppose someone has a well shaped but very flexible arch. The foot starts off not pronated. In walking or running the body weight is applied along the entire length of the arch and the foot flattens and then can easily pronate. But in cycling the power is applied through the ball of the foot. With no force being applied further back along the arch and to the heel, I don't see how there can be stress on the top of the arch to flatten it and then pronate the foot. And in any case when pronation does occur while cycling it seems to me intuitively that the support should be more like a wedge under the inside of the ball of the foot where the contact with the pedal and force application are rather than under the arch which is not in contact with the pedal and not participating in the transmission of force. What's wrong with this thinking?

Honestly, not trying to fight with you. I agree that proper foot support is important. But that's not the whole story that's all. If you're getting pain, and foot support doesn't solve it, maybe it's something different. I've spent the past four years of my life studying biomechanics, and the answer to sports related pathologies are never as simple as you're making it. Also, newsflash, the "convention" is not always right. Do what you want though, not my feet, not my knees.

You are quite right.

Very helpful post Magic...many thanks. One poster stated that the P.I. insoles...P.I. being known for their quality products...are more robust than Specialized insoles which in my experience have been pretty durable.

Quick question...on Zappo's site, it shows the pieces that come with the P.I. insoles. How are the interchangeable arches attached to the insole? Adhesive?...Velcro?

Thanks again.

No he isn't.
The simple fact is the ball isn't planar i.e perfectly flat. The ball/ forefoot distorts under pressure. For some people this is pronounced...for those with flexible feet. For those with a more rigid foot, not so much. As the forefoot distorts under pressure, pressure is redistributed away from the ball and longitudinally toward the rear of the foot and along the arch. Technically there are three arches to a foot. If the arch isn't supported and the foot is flexible, the foot can pronate i.e. implode inwardly. This not only has consequence to the foot because excessive flexing of the foot has consequences but also consequence to knee alignment. Btw, some of us cycle with mid foot or rearward cleat position. Mine are between the ball and mid arch for example. My arches therefore endure a greater percentage of pedal pressure (by intent) compared to more fore positioned cleats. Mid cleat positioning is conducive to even distribution of weight across the foot versus more localized pressure to the ball which in my case creates nerve pain. Bottom line is...increasing the surface area of force is good for foot health. Little kids understand this intuitively if you watch them ride their bikes down the sidewalk and out of the saddle. They virtually all ride with mid foot positioning on platform pedals. Grave diggers know this as well. Not many jump on the shovel on the ball of the foot. Hang out by the graveyard if you want to learn more....lol.

In bold...well of course. But the premise of the this thread is to address the former, i.e. how to support the foot...and not debate other ancillary reasons for foot maladies.

I suppose. I guess my real point in my original post, was that it may be more worth your time to address faulty mechanics farther up the leg, than trying everything under the sun on the foot first.

This is very true.

However, stand on the balls of your feet. Look down. Are you arches flat or arched? Arched. Even flat footed people like myself will have an arch in this position. Changing where pressure (cleat location) is applied changes everything. Hence, you are both right. Two more points then I'm done here.

1. Flat feet and pronation are not *exactly* the same. Pronation actually refers to the angle between the heel bone and the ankle. The majority of the time, people with flat feet also hyper pronate. However, forcing an arch into a flat foot (that is not hyperpronated) is asking for inflammation problems.

2. PROPER pronation is a GOOD thing the foot has evolved to support and absorb shock from weight bearing activities.
https://rothbartsfoot.es/NormalPronation.html

You still miss the signature point...in bold what you wrote above. Which I might add is pretty astounding and to me elementary...especially for somebody like yourself allegedly focused on bio mechanics. I will now write it for the third time and hopefully you will get it. There should be no localized focus above the feet for poor mechanics. It starts with a human's interface to the machine...in this case foot to pedal. Alignment of foot to pedal preordains alignment of tibia from the foot and knee position and position of femur relative to top tube. Knee joints are pretty intolerant of side loading. So no, you are wrong about focusing on any particular area when it comes to the mechanics of the pedal stroke. It is a 'system' and there is clear linkage between foot alignment to the pedal vertically and knee alignment over the foot. Poor foot support can cause lateral pressure on the knee joint and through repetition, injury.

Hey no prob Campag - the PI insoles have a 2-ply construction. You tune them by sliding included foam wedges into pockets between these layers. This Video gives a good overview-heavy, marketing speak aside I pretty much just did the 2 tests shown in video and followed their recommendations. I should also mention these didn't magically solve my knee issue, by themselves, but were just one piece of several things I've tried in combination that seem to be helping.

Thanks again Magic.

It's not elementary; I'm looking beyond the obvious. Things in your body can be wrong apart from the foot. Yes, the interface is the obvious choice , but faulty action up the kinetic chain can happen as well and effects the rest of the body. Every faulty joint effects the joint above and below it. To limit your focus on the foot is incredibly closed minded and quite frankly elementary.

It starts with the connection to the bike which is the foot. Foot alignment ordains knee alignment. The asymmetric human body attempts to acclimate...sometimes with limited success to the unyielding symmetry and repetition of the machine which is unforgiving in its consistency. Countless repetition exposes lack of agreement and injury. Load of the feet changes alignment if unsupported. Angle of foot platform affects knee tracking and alignment.
There is significant cause and effect between foot support, alignment and knee health. If you were to query a focus group of top cycling fitters throughout the industry, that would be their response. You can hypothesize all kinds of different cause and effect scenarios but it starts with the foot connection to the machine which is the focus of this thread...not your unrelated and extraneous postulations.

not to be contrary, but in my feet, whether walking, cycling or any other activity which applies force thru the ankle, the force first goes thru the ankle and then the arch and then, at some point (unless I'm walking on my heels) thru the forefoot.
Here's something to try.
Standing, with straight legs and feet flat on floor, WIth feet confortably spread (usually about hip width or just under), shift weight enough so that most of weight is on one leg, a very subtle shift. Now looking down at your feet/ankle, shift your weight back so that it's equally distributed between legs. For many/most of us, the foot will roll inward, the ankle will roll inward - pronation. The degree of this depends on many varied factors.
DO the same, but this time on the leg without any significant weight, raise the heel, bend the knee, so that when you shift the weight, the final pressure to the floor is all thru the forefoot. Now shift weight again so it' equal between legs, note the the inward roll of the ankle. It will likely be more than before - more pronation.
The heel is a major part of the foot structure, whether you weight the heel or not.
Everything goes from the ankle forward. If the heel, therfore the ankle, is stabiliized the arch deflects less, and the force at the forefoot is directed more equally across the forefoot.
From my experience, valgus shimming is the end of the chain and isn;t as good a fix as one which starts at the ankle and moves forward.
Varus adjustment starts the ball rolling. Supporting an arch can add a little, but is not that essential. Then a valgus adjustment is icing.

Even for cycling, where the heel is 'unweighted', unweiughted does not mean without force thru the ankle.
Now try this.
First test above, foot completely on floor. But this time, place a thin magazine (2-3mm) under just the inside of the heel of the unweighted foot. Now weight that leg/foot and watch the ankle, you'll likely see much less inward roll, less pronation. That's varus adjustment - crude, but still adjustment.
Now, in the world of stiff soled cycling shoes, we have the advantage of using varus adjustment to stack the ankle well, so that pronation can be addressed from the ankle forward.
If you're not sure... do first test, except this time place 3mm magazine under the ball of foot - just under the ball,, not the whole forefoot, not the heel, now weight the foot. Ankle still pronates. In fact, forefoot twist mores, you take it from there...
Feet are very complicated, nothing simple.
Full foot orthotics done by a real sports specialist would do the best. The inserts we get in most cycling shoes I've seen are throw-aways, as are those in ski boots and most other sportsw footwear. my take