!!!Plantar fasciitis – Combining orthopedic and sensorimotor foot therapeutical concepts

The sensorimotor foot orthotic activates or blocks muscles; the classic orthopedic foot orthotic supports and beds: However this notion is too easy. Classic approaches in the foot orthotic care sometimes create the conditions so that the sensorimotor system once more can function correctly. This can be seen with the example of foot orthotic care in case of a plantar fasciitis.

As it is known to all readers dealing with the sensorimotor system, this system ideally is supposed to provide automatically motion to the body.  We have trained and thus automized this motion pattern before through many repetitions. At the same time the sensorimotor system is a strategy system that actively interchanges information with all other systems in the body (Laube, 2009). Here pain is a big interference factor, because it changes learned motion pattern. This is also the case with pain at the plantar fascia.

The nociceptive system requests the patient to not use any more the area of pain or to avoid motion causing pain as much as possible. Nocioception is the perception of stimuli that can harm the body potentially or actually. These stimuli are registered by nociceptors and via afferent pain fibres conducted to the brain, where pain perception develops.

Do not only look at feet when doing cause studies

The reason of origin of plantar fasciitis has not been conclusively scientifically resolved. More than likely there are various factors that play a role. Overweight people, but also above-average active people like runners and athletes are considered to be endangered. Also standing up for a long time at one’s workplace can trigger an overload of the plantar fascia. Most often plantar fasciitis occurs at the age between 40 and 60 years.

Typical of plantar fasciitis is radiating pain from the heel to the medial side of the foot arch. In my professional practice I have observed for many years that most patients with plantar fasciitis rather have a highly lifted foot. If such a foot lowers in the medial longitudinal arch, inevitably tension on the plantar fascia follows. A flat foot, according to my experience, does not create problems that often.

Since we always also ask our patients about their living circumstances, we know that a plantar fasciitis is often the consequence of burdening living situations and stress. Of course this does not directly effect the plantar fascia. But we know from fascia research that messengers are produced when we are in stress that can lead to a slow fascia stiffening. This can also have an effect on the foot via myofascial chains, for example via the so-called superficial back line, also called dorsal chain. This goes from the metatarsophalangeal joints over the plantar fascia and the rear side of the body up to the cranial vault to the eyebrows.

Here the footsole, the Achilles tendon, the calf muscles, the rear femoral muscles, the long musculus erector spinae and the connective tissue lamina of the cranium are in myofascial connection. The function of the superficial back line is supposed to be the support of the body in extension movements (stretching) and stabilization in upright position.  (According to: Schleip/Baker, 2015). Disturbances and motion limitations in this chain can thus also have an effect on the foot. If we treat plantar fascia, we should not only look at the foot, but we should always also consider the living circumstances and the fact that pain can be caused not only by the foot itself.

First goal: Pain reduction

In order for the sensorimotor system to do good and undisturbed work again, the first task is to eliminate pain. Since pain results from the inflammation of fascial structures, we have to fight the inflammation first. In the literature there are several methods described, for example to bring oxygen into the system to accelerate the decomposition of the inflammation. Also transversal flexion of the fascia, diverse stretching exercises, but also treatment with equipment  from shockwaves to laser therapy are described.

This means for the foot orthotic care in case of severe pain that the foot first only is embedded and unloaded. The sensorimotor foot orthotic can and should be an important part in the further course of the therapy, because it not only can unload painful, inflamed areas through appropriate bedding. It can also fight the causes of the inflammation by creating new conditions for locomotion.

Righting the foot and enabling locomotion

If you look at the foot in an isolated way, often the cause for a plantar fasciitis is a lowering process of the foot. The simple illustration (picture 1) shows the hyperextension of the plantar fascia in case of a lowering of the foot. But who only looks at the foot in an isolated way, overlooks that in most patients the dorsal fascial chain is too short. Patients with these symptoms usually also have back pain due to this shortening.

In the next simple illustration (picture 2) you can recognize the foot from plantar and how the position of the joints to each other changes by the lowering of the foot. The resulting medial hyperextension of the foot leads to an inflammation in this area. Therapy should right the foot again and thus take the tension away from the plantar fascia.

The muscle requirements to secure the righting of the foot arch are as follows if you only regard the shank: The M. tibialis posterior does not work enough between the stance phase and the push phase. The M. triceps surae works too much and pulls the Os calcaneus up in the back over the Achilles tendon. Since the medial part of longitudinal tension arch of the foot is higher than the lateral part, a medial lowering and buckling of the foot and a hyperextension of the plantar fascia is the consequence.

This is the basis for the requirement of the sensorimotor foot orthotic. The excentric task of the M. tibialis posterior is to be stimulated. Beneath the Sustentaculum tali and the short part of the talus, the highest point of the medial pelotte is placed (picture 3). The plantar fasciae hereby remain unloaded and the opposite support at the lateral side secures the hindfoot on the foot orthotic. (Picture 4 a,b).

From the point of view of classic pedorthics first it is a mechanic righting of the calcaneus. And that is how the pelotte is supposed to take effect. From the sensorimotor point of view it is important what we actually effect with this righting. With the righting of the foot we extend the dorsal chain and shorten the way of the M. tibialis posterior. The immediate effect is that we also bring the insertion and the origin of the plantar fascia together and thus unload it. But the M. tibialis posterior is also stimulated to more activity by this shortening of the way.

The tonicity is thus increased and the muscle actively contributes to the righting of the foot. With the extension of the way at the dorsal chain (calf muscles) we reach a reduction of tonicity and thus a relaxation and a decreased tension on the plantar fascia. So using a classic pedorthic measure, we have created a new condition so that the sensorimotor system can organize motion newly and more physiologically. If this works, depends to a large extent on how we elaborate and place the medial pelotte.

If we support the longitudinal arch of the foot holohedrally, we paralyse the talonavicular joint and thus prevent motion. This only makes sense in case of severe pain, if the foot has to be immobilized as much as possible in order to avoid painful motion. But as soon as motion is possible again, we have to enable and stimulate motion in the talonavicular joint with the help of our foot orthotic. Only this way the sensorimotor system is able to organize motion that leads to muscular balance and thus unloads the foot permanently.

The retrocapital pelotte in the forefoot is elaborated with steps in order to create an extension of the dorsal muscle chain (picture 5). This way we put pretension on the dorsal myofascial chain and this way reach a reduction of the tonus order and thus relaxation. The sensorimotor system rules muscular motion in our body. Each modification of this motion, created between foot and floor, has to be corrected by the central nervous system (aktio=reaktio). The aim of the sensorimotor foot orthotic is to create this motion more physiologically and to maintain the patient’s own motion pattern, as far as possible.

By extending and shortening of the respective myofascial areas the sensorimotor system receives a new request for motion. In every case of foot orthotic care you should be aware that basically there are no foot orthotics that do not have a sensorimotor effect. Each modification beneath the foot makes new demands on the sensorimotor system, also a foot orthotic built according to classic orthopedic principles.

This raises the question which reaction is caused by the foot orthotic. A static foot orthotic that only supports the foot and limits motion cannot lead to better motion repetitions since not all motions are provided by the foot orthotic or are prevented by it. The difference is often not very big (picture 6). Three millimeters less beneath the Os navikulare and already we give the chance to the mechanoreceptors to require a muscle activity of the neuronal system and to modify motion. Thus it is also important to examine the foot before the foot orthotic care and to test how it will react to the orthotic.

If the new motion result leads to better motion than the previous one, it can cause reduced stress for the plantar fascia. This way also the cause for the inflammation can be eliminated. Sensorimotor foot orthotics have developed from conservative foot orthotic care. If a foot orthotic has a sensorimotor effect, this does not mean that it does not also include classic principles like support, retaining, guiding. As opposed to purely supporting foot orthotics, the sensorimotor foot orthotic does not remove the task to organize motion itself from the sensorimotor system. It stimulates the sensorimotor system to discover motion newly and to automize it.

Address of the author:

OSM Lothar Jahrling
Schiffenberger Weg 59
35394 Gießen, Germany