Plantar fasciitis is a very common pathology which seems to plague a diverse population of people. I have seen it everywhere from high-performance runners, putting 50 miles per week on their feet, to your average individual who sits at a computer most of their day. To say that it only affects certain people because of one specific reason underplays this pathology’s complexity. For this reason, I would like to attempt to break down the involved anatomy in order to clarify what structures are involved. Then, we will adventure into how biomechanics plays an important roll in this problem. Lastly, I will attempt to give a few tips on how to treat the issue.
Before we get into the well thought out, stringent plan that I just put before you, let us ignore it for a second and touch on a condition that plantar fasciitis can be mistaken for.
Bone spurs are probably the most commonly mistaken pathology when it comes to diagnosing plantar fasciitis. The two conditions can present with very common symptoms and, thus, misdiagnosed. The only way bone spurs can be truly diagnosed is with x-ray, so commonly plantar fasciitis is misdiagnosed first when an x-ray has not been done but pain symptoms are present. If symptoms of plantar fasciitis do not improve after standard treatment, usually diagnostic testing will then be done to see if there are further issues (such as bone spurs). I will note that both plantar fasciitis and bone spurs can be present at the same time making diagnosis even more tricky. Also, bone spurs can actually be a result of chronic plantar fasciitis making these two conditions even more interconnected. You can now understand why the two are mistaken easily.
Okay now that we have that out of the way, let us get to the good stuff.
|The Plantar Fascia is a strong sheath of dense tissue on the bottom (or plantar) of the foot. It originates from the tuberosity of the calcaneus (front of the heel bone) and fans out over the bottom of the foot towards the toes. It is responsible for creating support for the arch and absorbing shock as we run, walk, jump and generally live out our daily mischief. It works in unison with muscles of the calf and foot to create the ability to move in a smooth effortless motion. Without this unique structure, the foot would not have the support it needs to maintain its arch and function as the efficient spring that it mimics. This would lead to a host of other joint alterations which we will not get into. Generally speaking, you really need your plantar fascia.
Now that we, as I like to say, have our anatomy doctorate after that 1-minute lesson, let us continue on.
So what is plantar fasciitis and why does it occur?
True plantar fasciitis by definition is the inflammation of the plantar fascia. This occurs due to minor tearing of the plantar fascia and the build-up of scar tissue as a result of these tears. This causes pain on the bottom of the foot, usually where the heal and arch come together. It can present in other parts of the arch and bottom of the foot but those areas are not as common. The pain is usually described as a burning or tearing sensation. This occurs because the sensation felt is actually the re-tearing of the newly formed scar tissue. Pain is usually worse in the morning with symptoms improving as the day goes on. This is because the time spent off one’s feet while sleeping allows for minor healing to happen. However, once weight is put back on the feet in the morning, that freshly laid down scar tissue gets re-torn and the process begins again. It is a vicious cycle which can be tough to break. When this has occurred long enough, actual tearing can occur at the periosteum (where the plantar fascia actually connects to the calcaneus). This is usually when the pain becomes much worse and inflammation increases.
It is important to realize that the treatment of plantar fasciitis is usually not done correctly. The common treatment of NSAIDS, ice, steroid injections, and stretching are not going to correct the reason why this occurred in the first place. They may help with the symptoms but the chances of the pain returning is high and the likelihood of a chronic issue developing is very high. The realization needs to be made that these kinds of treatments are simply a way of treating symptoms; not the root cause. In other words, we always need to find the cause of why this happened in the first place, not just treat the pain.
The root cause of plantar fasciitis is ankle mobility and great toe biomechanics. This involves the muscles of the lower leg and foot. As we walk, the foot and ankle need to be able to move freely in order to operate correctly. This freedom allows for proper stride length when we walk. If there is not enough flexibility in the ankle and foot, these mechanics can be altered significantly. First, if the great toe does not have the ability to extend (bend back), the entire motion of one’s stride is disrupted and the foot is forced into an altered motion. This presents with the great toe using more with a side to side motion and not using its natural ability to extend. When this occurs, the foot and ankle compensate with either eversion (turning out) or inversion (turning in). This compensation, in turn, puts increased load on the plantar fascia.
Adding to this, the ankle needs to have enough ability to dorsiflex (the motion done to bring the toes toward the shin) to function correctly. Without this ability, the mechanics of walking are changed by forcing the heal to come off the ground prematurely. This causes increased pressure to be put on the plantar fascia leading to overloading, overuse, and potential injury. THIS is what causes plantar fasciitis.
So what do we treat? The primary theory of treatment as far as mobility is concerned relies on increased dorsiflexion for the ankle and increased extension for the great toe. By doing this we can decrease the overloading of the plantar fascia which in turn will break the cycle of re-injury and allow it to heal properly
|The primary structure that is involved with ankle motion regarding plantar fasciitis is the tibialis posterior muscle. Yes, there are plenty of structures that limit dorsiflexion and should also be addressed, but this muscle in my experience is a primary culprit which causes chronic misalignment of the foot and the inability to have a correct stride due to improper dorsiflexion. When this happens, extra load is then put onto the plantar fascia; creating the potential for overuse and injury. On top of it limiting dorsiflexion it can also lock the foot into inversion which coincides with the inability of the great toe to extend. This muscle can also mimic plantar fasciitis by causing inflammation on the inside of the arch by the calcaneus. As the tibialis posterior courses around the ankle, it passes underneath the flexor retinaculum which can become adhered and cause inflammation and discomfort. Coincidentally, this location is where most plantar fasciitis symptoms occur. By treating the tibialis posterior your truly allowing the ankle and foot to move correctly and in the process, taking pressure off of the plantar fascia which will allow it to work less and begin to heal.|
|The next important structure is the flexor hallucis brevis. This muscle contributes greatly to the inability of the great toe to extend. By treating this muscle we are, in effect, allowing the great toe to extend, and also the rest of the foot to function properly by not needing to invert (turn in) or evert (turn out) in compensation. Although a simple motion, being able to easily extend the great toe can greatly affect plantar fasciitis by taking the load off the arch of the foot.
This muscle is also located very close to and runs parallel to the plantar fascia. Any shortening or adhesive tissue laid down in this area can affect the flexor hallucis brevis and limit its ability to extend.
The flexor digitorum brevis and longus can also be involved due to their close proximity to the plantar fascia in the bottom of the foot. When these muscles are involved, it is more because of overuse due to the poor foot mechanics we have just discussed than being a root cause.
Plantar Fasciitis Stretch
In order to truly gain lasting increased dorsiflexion of the ankle and thus recreate proper foot mechanics, we must incorporate a stretch which will pinpoint the distal part of the calf. If we look at the anatomy, the gastrocnemius muscle crosses the knee and the ankle joint. Due to its unique anatomy, it limits the ability of the ankle to dorsiflex completely when the knee is straightened due to Achilles tendon tension. In other words, any stretch with dorsiflexion as our primary goal needs to eliminate the gastrocnemius’ tension in order to fully stretch the rest of the structures to their full length. This can be done by simply bending the knee when we stretch the calf. Below is a demonstration of a correct stretch to increase dorsiflexion and help plantar fasciitis.
It is important to note that after all of these structures are treated, plantar fasciitis takes some time to heal once the foot and ankle is working properly. This is especially true if this has developed into a chronic issue over a long period of time where the periosteum has begun to pull away from the calcaneus as mentioned before. However, this can still heal if given the right environment and functionality.
For more on this topic, read Plantar Fasciitis… and All Its Glory- Part 2.
If you like what you read and would like more, please subscribe via email to receive articles directly to your inbox. Thanks for reading!