Whoa! It's been a while since I've been able to get some data to answer a few questions that have come my way. One of the biggest search phrases that brings my blog up is the question "do cycling shoes cause plantar fasciitis?" So now I'm going to give you a concrete answer! Yes...and No! don't cuss me yet. I know I've been very stern in saying that cycling shoes do not cause plantar fasciitis, but a poor fitting shoe along with poor placement of the cleat on the shoe and its alignment with the pedal spindle can contribute to the onset of plantar fasciitis.
Here's why I say yes and no. As I've stated before, cycling shoes have a very rigid sole. Therefore there are fewer moving parts in your foot. As would be present in running and jumping, the force through the plantar fascia is minimized. With the plantar fascia not having to maintain the integrity of the arch of the foot while cycling combined with fewer moving parts in the foot means less wear and tear in your foot period!
However, any poor fitting shoe can cause subtle changes in the way you use your feet. If this change goes against normal movement patterns and normal mechanics of your foot, then this can provide an opportunity for foot pain.
Here are some guidelines to follow for proper fit of your cycling shoes:
Your foot should fit in a cycling shoe quite snug and with no heel slippage in the heel box of the shoe or in the mid shoe. The mid shoe shouldn't fit so tight so as to cut off circulation to your forefoot and toes though. If your toes have room to breath and move in the toe box.
So, I got a hold of some lab rats, you know volunteer cyclists to test out a theory. Over a couple of months time, we were able to collect some good data.
What I found were two very specific fitments that caused "plantar fasciitis type" symptoms:
The first problem: is that if the cleat of your cycling shoe is too far forward on your shoe then this can cause excess heel slippage in the heel box of your cycling shoe and it puts excess pressure on the ball of the foot, especially the on the joint of the first or big toe (the 1st MTP joint). When fitting a cleat on your shoe, the ball of your foot or the bottom of the big toe should be directly in line with the spindle of the pedal. If the cleat of the shoe is too far forward, then the big toe will have an excess amount of force going through it. Given this misplacement of the cleat, a lot of force is going to be placed on the bottom of the big toe. This will cause a "hot spot". If the cyclist continues riding with this cleat placement, then the hot spot can become more symptomatic. The flexor hallucis longus muscle is being isolated with this placement. The tendon from this muscle runs through the arch of the foot until it joins with its' respective muscle in the leg. Given the circumstances, the tendon will be prone to an overuse or repetitive use syndrome. It's possible that this inflammation can affect adjacent tissues in the foot. And then voila, you begin to experience plantar fasciitis type symptoms.
Just a side note: In the usual presentation of plantar fasciitis, pain usually begins at the heel. However, when examined for plantar fasciitis, the examiner will extended the toes to put tension on the plantar fascia. By doing this, tension is placed on the plantar fascia and then it is palpated. If pain is present on the first joint of the big toe or in the other four toes, this indicates the possibility of plantar fasciitis. However, this symptom alone is not conclusive of plantar fasciitis.
The second problem: with the placement of the cleat too far forward, it causes a biomechanical dysfunction of the ankle and foot during the down stroke of the pedal cycle. Because the pressure on the foot is too far forward, this causes what is called a "contact cue" to push harder with the toes. When pushing harder through the toes, the heel tends raise up and stays in a raised position through the entire pedal stroke. With a proper pedal stroke, the heel should be "planted" or pressed down when the foot comes over the top of the pedal stroke. In more simple terms, you are pedaling as if you are standing on your toes. The calf muscle and soleus muscles are now being used in a very shortened position during the down stroke of the pedal cycle. This in turn with a high volume of cycling and pedaling can cause a shortening of the calf muscle. With this shortening, you develop an abnormal tissue length tension or tight calf muscle. Tightness in the calf muscle is a precursor to developing plantar fasciitis. For those of you who are duathletes or triathletes, this is very important for you to understand. Make sure you're planting your heel over top dead center of the pedal stroke and use the calf muscle to help power you through the down stroke. This will also make the bike/run transition a much easier one.
An issue that is not so relevant to cleat placement is:
The heel in the heel box of the cycling shoe. I ride the Sidi Ergo 2 Carbon shoe. This shoe is an incredibly comfortable and responsive shoe. However, even with the fancy adjustable heel box on this shoe, the heel box can still wear out. I've had my shoes for nearly 5 years now and have kept them in pristine condition...on the outside. The material and padding in the heel box have now lost the resilience and the heel liner has worn through. This in turns leaves space in the heel box. This space allows my heel to slip.
The heel box or shoe itself can wear out thus causing a change in foot mechanics in the shoe. Typically the mechanics of the foot are for the worse. If your heel begins to excessively slip, the natural tendency is to go into a pointed foot position, you know, the one we previously talked about in this post. But instead of developing pain in the ball of the foot or MCP joints, pain is developed in the back of the heel and can even manifest in the bottom of the heel. HOWEVER, this heel pain again is not the heel pain that usually arises with plantar fasciitis. The heel pain that arises is typically felt on the back of the heel where there is repetitive chafing. But, I say it again, this changes the mechanics of your foot in the shoe as well as how you use your foot during the pedal stroke. If you use the compensated mechanics long enough with the toes gripping excessively in order to stay positioned properly in your shoe, then most likely you will end up with a muscle imbalance in the leg or foot and experience plantar fasciitis type symptoms.
At first glance, cycling appears to be an easy sport or recreational activity to jump into. However, as you begin to love the sport more and engage in it more, it's important to realize the effect it will have on your body. There's a reason why cycling equipment, clothes, shoes, etc can be moderately pricey...or more so often very pricey, it's because if you don't invest in good equipment and obey the laws of biomechanics, forces, and reactions, something is going to give.
So for those of you that have or are experiencing plantar fasciitis like symptoms or plantar fasciitis period from cycling, look at your fitment on your bike. Have a fitting performed, preferably with a system that can look at and analyze your spin stroke and power output throughout the entire pedal stroke. That being said, someone with a Computrainer Lab using spin scan analysis would be perfect. It's amazing what a 1 - 2 mm change in cleat position, a change in forward or aft seat position, and/or a very small change in seat height can do to improve power, efficiency, and especially comfort on a bike all while maintaining the integrity of your legs and feet.
Happy Cycling and Bipeding
Brad Senska, PT, DPT, BS, ASTYM.
bradsenska@yahoo.com