- 1.FOOT CORRECTION part 1: ARCH SUPPORT
- 2.FOOT CORRECTION part 2: WEDGING
- 3.FOOT CORRECTION part 3: SHIMMING
- 4.POWER TO THE PEDAL – CLEAT POSITION
- 5.WEDGING / SHIMMING / ARCH SUPPORT UPDATE – The Cory Davenport method of foot correction
- 6.FOOT CORRECTION METHOD: How to go about it
- 7.INTERESTING FIT PROBLEM No. 4: FOOT CORRECTION METHOD UPDATE and warning about FFMD readings
Arch Support is the primary and most important part of Foot Correction. This post will explain why.
As I mentioned in Basic Premise the Team and I use a method of quantifying and restoring the prioritising of the proprioceptive feedback from the feet . Without going into the details of the method itself, the basic picture is this:
Proprioception is name given to the sense comprising our unconscious awareness of our position in space. Specifically, it is the cerebellum’s awareness of the body in space. The cerebellum is the part of the brain that controls unconscious movement. “So what” you might say.
97% of daily movement is unconscious. Yes, it’s a conscious decision to get out of bed but you don’t consciously determine which muscles fire or the sequence in which you fire them to accomplish the task. Cycling is largely an unconscious activity. You decide to accelerate, brake, corner or move up in the bunch. They’re all conscious decisions but once made, again, the muscle firing sequence used to accomplish those varied tasks is unconscious and is controlled or overseen by the cerebellum.
There are several things worth noting about the cerebellum.
- It can be consciously overridden but cannot be consciously controlled. An example may be that you are riding a hill, consciously dropping your heels more than you usually do because someone has told you that there is some benefit to this. If you become distracted however, you will revert to your normal unconscious pedalling technique because conscious overriding has ceased and unconscious control has resumed normal (and usually more efficient) service.
- The cerebellum has more than 200 million neural connections to the body; more than the rest of the brain put together.
- And most importantly, the cerebellum is absolutely inundated with neural information and ignores the vast majority of that information.
Every second 3 billion or so proprioceptive signals emanating from muscles, joints, bones, fascia etc arrive at the cerebellum alerting it to the load being experienced, position in space and relationship to gravity of all of the constituent parts of the body. The cerebellum uses this information to determine what muscles to fire and exactly when to fire them to efficiently perform any particular task at hand. This sounds like a great system, and it is, but there is a flaw in the system. ‘Flaw’ is probably not the best choice of words, but of those 3 billion signals mentioned above; the cerebellum only has the capacity to process around 2 thousand; 1 in every 1.5 million!
So how is it we can coordinate our actions as well as we do despite this paucity of processing capacity?
Evolutionary pressures have dictated the development of a hierarchy of priorities (filter) as to what proprioceptive information the cerebellum prioritises for processing versus the vast majority that it is ignored. Only 2 categories of stimuli are prioritised.
- Generation of force. Any time we exert ourselves, that exertion is taken on as a priority task, not just by the cerebellum, but by the entire central nervous system (CNS / brain and spine) because it has survival value. If you are running for your life or fighting for your life, you are literally betting your life that you are going to perform those actions as well as you possibly can for the most important reason of all. Survival. Every other consideration is secondary when compared to survival.
Within this category of ‘force generation’ stimuli arriving from the lower body are given higher processing priority than stimuli from the upper body. Again there is an evolutionary imperative at work. We have evolved to be upright, bipedal creatures whose primary mode of locomotion is walking. Given that’s the case and the need to do it, and also given the vast disparity between signal output capacity and the ability to process it, it makes zero evolutionary sense if whenever we’re walking around and decide to use our upper bodies in some way, that we collapse at the hips, knees and ankles. This is the risk if upper and lower body are given the same priority.
So, because the pelvis and below is the postural foundation that allows us to maintain our upright, bipedal position it gains higher processing priority than the upper body.
- Any change in the quality of stimuli arriving from a given area of the body will always attract processing priority. A good analogy is this: You and a friend are at a sporting feature with 1.5 million people in the crowd. (It is no accident that there are 1.5 million attending. 1.5 million times more proprioceptive info arrives at the cerebellum than can ever be processed). All these people are talking which creates a lot of noise. Meanwhile you are engaged in a conversation with your friend and that is the focus of your attention. Even so, you’re aware of the background noise but are ignoring it.
Until a rude fan in the row of seats behind you leans forward and shouts loudly in your ear and consequently attracts your (unwilling) attention because their loud voice is a significant change that stands out from the background noise. That’s the analogy.
For a real life example, use one finger to flick the other hand. You become more aware of the part of the hand that was flicked for 5 – 10 seconds that the change in stimuli lasts before dying down. It doesn’t last because the cerebellum has an incoming torrent of information arriving every second that it needs to deal with and cannot stay focused on any particular area unless there is a strong need to.
All of this is necessary background preparatory to making a simple but very important point. Proprioceptively speaking, while riding a bike next to NO ONE KNOWS WHAT THEIR FEET ARE DOING!
We don’t know that we don’t know because we all compensate amazingly well by receiving quality proprioceptive feedback from the hips, knees and ankles. But all compensations exact a cost; in this case a dual cost.
The first cost is that any attempt to compensate for any challenge to our position in space (of which there are bazillion potential challenges) will always evoke an immediate, unconscious compensatory response from the CNS. Our CNS is incredibly adept at compensating for suboptimal function or in the case of cycling, a suboptimal relationship to the bike. The key observation here is that ALL COMPENSATORY RESPONSES INVOLVE AN INCREASE IN ASYMMETRY. This may be small, it may be large, but it is always present. Cycling is a symmetrical activity so for best efficiency and lowest chance of injury, any factor that allows the rider to function closer to ideal bilateral symmetry is a positive. Any factor that increases asymmetry is a negative.
The second and possibly larger price we pay is that a lot of neural capacity is constantly engaged in an ongoing and fruitless search for the feet while cycling. I would rather that wasted capacity be made available to allow the rider to more efficiently globally coordinate the cycling action.
Why doesn’t the CNS clearly recognise the feet while cycling?
When we walk, run, cycle or take part in any primarily lower body activity, the cerebellum oversees rather than directly controls the muscle firing sequence of the legs. The pattern of flexor on / extensor off……. extensor on / flexor off, is controlled by the Central Pattern Generator (CPG), a bundle of neurons in the lumbar spine area. The CPG is like a dumb computer that just fires in an ‘‘on / off……….on / off” pattern. It needs to know when to fire and for that to happen, it needs an informational input. The CPG’s informational input is force feedback from the feet and I believe (and can demonstrate empirically) that the primary component of this is changes in plantar fascia tension.
The plantar fascia sits in the arch of the foot and connects the calcaneus (heel bone) to the MTP joints (base knuckles of toes). When we walk and run, natural activities we have evolved to perform, plantar fascia tension changes constantly and it is the change in tension that attracts processing priority. When we push down on a rigid soled cycling shoe, an unnatural activity that we have not evolved to perform, there is little or no change in plantar fascia tension because there is little or no contact between the typical, low quality cycling shoe insole and the arch of the foot. This means that we lack fine awareness of the part of the body that transmits every watt of power we produce to the bike!
This lack of neural clarity is a challenge to our position in space which is met with an asymmetrical compensatory response which can vary from insignificant to substantial depending on an infinite number of other individual factors.
The solution is to create some contact between a cycling shoe insole and the arch of the foot.. This is where arch support comes in. It is needed, not so much for physical support of the arch but more to trigger a greater clarity of neural information exchange. Any factor that gives the CNS more complete or better quality information about load, position in space or relationship to gravity of our body enhances our ability to globally coordinate our actions.
In turn this removes an avoidable challenge to our position in space, eliminating any need for an asymmetric compensatory response arising from that particular challenge. Consequentially, this reduces the chance of developing overuse injuries, and on a bike, crashes aside, ALL cycling injuries are overuse injuries.
The level of arch support used is crucial in an individual sense. It needs to be enough to create obvious upward pressure on the plantar fascia so that on the pedal down stroke, plantar fascia tension increases as the foot is loaded while on the pedal upstroke plantar fascia tension decreases as foot is unloaded. This cyclical change in plantar fascia tension attracts the attention of the CPG and allows it to fire optimally rather than sub optimally.
Levels of arch support can be categorised as Level 1 – Not Intrusive, Level 2 – Mildly Intrusive or Level 3 – Very Intrusive. The individually optimal level needs to be such that it creates obvious upward pressure on the arches of the feet while standing in cycling shoes off the bike. While cycling, the correct level of arch support means that it can be felt but is by no means uncomfortable. If it is uncomfortable while cycling, then the arch support height needs to be reduced. This is as good a description as any of the desirable Level 2, Mildly Intrusive. No matter what level you perceive a given height to be, if it is uncomfortable while riding for more than an initial 10 minutes, it is too high.
Does everyone need arch supports while cycling?
No; but more than 99% do need it. Very occasionally I will have a client who processes proprioceptive feedback from the feet while cycling without any need for arch supports. Some of these people find any level of arch contact painful. Most don’t and adding arch supports doesn’t do them any harm, nor is it of any particular benefit. Why?
Speculating, I suspect that they’re just born or develop better than the rest of us. I hypothesise, but have never been able to test the idea, that if we all grew up barefoot and functioned from infancy without shoes or socks, which hinder full development of proprioceptive awareness of the feet by the CNS, then arch support while cycling would be unnecessary. It’s an idea that I can’t prove or disprove; yet.
Recently I fitted a gent who did not need arch support or any other form of foot correction. He was happy and sent his father to me. He didn’t need any form of foot correction either. People like this are out there but are uncommon.
Can anyone who needs arch support ride without it?
Of course. Most cyclists are already doing just that. At some level, great or small, they are paying a compensatory price. In many cases they’re not aware of this. In other cases the niggles, aches or injuries they may experience can in part or in whole be attributed to the lack of proprioceptive clarity between feet and CNS.
Which brands of arch support insoles do I recommend?
I don’t like using the conformable, heat moldable, mass produced insoles because most riders do not get the molding process right and end up with too little, or less commonly, too much arch support. The ubiquitous Superfeet are generic, far too generic, but work really well for those with very low but otherwise normal arches (though not flat feet). Again, if they feel ‘mildly intrusive’ when standing in them, they’re fine. If they feel ‘not intrusive’ there is not enough arch support from a proprioceptive point of view.
There is a German brand named Solestar that I would specifically suggest you avoid. Solestar insoles are well made but misguidedly, are designed to elevate the outside edge of the forefoot. For 99+% of those who would benefit from appropriate arch supports in their cycling shoes , this elevation of the outer edge of the forefoot is the opposite of everything I’ve learned over nearly 30 years. I don’t see many clients with Solestars but in each case have been able to demonstrate to the client’s satisfaction that they were a problem.
For the majority, the best options I’ve found (there may be others I’m not aware of, Icebugs seem interesting) are Sof Soles Fit and G8 2620’s. They’re available in a wide range of sizes which between the two brands cover from size 37 – 48. G8’s are sold as a kit with five modular arch support options of differing heights. Sof Soles are fixed heights that equate with the 3 highest G8 arch insert options. Of the two, both are good but the G8’s have the advantage of a wider range of arch insert heights that are less rigid than SofSoles. Both have a rigid heel cup base. G8’s have the further advantage of being much thinner in the forefoot area. This allows them to take up no more vertical space in a cycling shoe toebox than a standard cycling shoe insole. SofSoles are thicker and occasionally are too thick in situations where there is not much vertical space in a shoe toebox.
Don’t fall into the trap of thinking that you will necessarily need the same height option of arch support for each foot. It should feel the same on each side and for most this will mean the same height. Some will require a different arch height on each side.
Once arch support is introduced and used for a period, further adaptation to its use can occur in some riders. What this means is that if an arch support option feels like the desirable, mildly intrusive Level 2 when standing, but over time begins to feel that it has diminished to a not intrusive Level 1 on one or both feet, then it is advisable to experiment with a higher option.
If you have obvious callousing or thickening of the skin on the sole of one or both feet immediately below 2nd, 3rd or 4th MTP joints (base knuckles of the toes), this suggests that there is localised loading which can possibly cause discomfort from nerve compression while Wedging or Shimming. In these cases the likely solution is a metatarsal pad that lifts and separates the MTP joints on the nerve plexus that is located between each pair of MTP joints.
Some cycling shoe manufacturers have realised the need for arch support; Shimano, Giro, Specialized and others are to be commended but they are only taking baby steps. I don’t think they really understand what they’re doing yet. In each case their highest level of arch support is too low for 75+% of riders in the sense of instigating an improvement in proprioceptive clarity of information transfer between feet and CNS.
Arch support is where Foot Correction starts. To really nail it we need to talk about Wedging (Foot Correction part 2) and Shimming (Foot Correction part 3)
Postscript: One of the Comments below relates to flat feet. If you have true flat feet or near flat feet, again use Level 2 arch support. Don’t be concerned if you need one of the higher arch support options to achieve Level 2. Arch support is all about how the rider perceives the level of support and is NOT about “low arch equals low arch support height”. It may do, it may not.
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