One or two orthoses

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I am not sure if this has been discussed previously but....

In the discussions around what prescriptions we write for patients, the tissue stress approach is very much geared around the presenting complaint. When I have asked colleagues what criteria they assess (in terms of alignment / function etc.), the response is commonly dependent on the pathology one aims to manage, bearing in mind, static structure does not predict dynamic function etc. If a tissue is likely to be stressed by increased pronation moments, then reduce those or increase supination moments etc.

Thus, in the absence of pain, providing orthoses would be somewhat more challenging and many would advocate (correctly) that there is no evidence to proivide orthoses in the absence of symptoms.

Being devils advocate, my questions are

1. If someone presents with unilateral symptoms do you provide them with one orthosis or a pair?
2. If you provide a pair, how do you decide on the prescription for the asymptomatic foot?

Trevor

 

An extension of your question is when do we give a patient an orthotic to prevent pain. The tissue stress approach is not entirely dependent on a response to pathology. For example, the tissue stress approach predicts that those with a more medially deviated STJ axis are more likely to have STJ pronation related problems (e.g. Post tib tendon dysfunction) and those with a more lateral STJ axis are more likely to have STJ supination related problems (e.g. peroneal tendonitis). So, in the absence of a complaint, but in the presence of a medially deviated STJ axis you could give someone an orthosis with a medial heel skive.

As for the statement that static structure does not predict dynamic function: that is true for the static measures that have been investigated so far. I would bet that if someone looked at STJ axis position and peroneal muscle EMG that you would be able to predict the relative amount of peroneal activity.

Back when I had rohadur orthotics, I broke one and walked around for half a day with one orthotic. At the end of the day, I started getting back spasms that went away when I was able to get to my spare orthotics. That is one reason to give someone two orthotics when one side is symptomatic.

Eric

 

We did discuss this s few years a go. Back stres as Eric mention was one reason.

Simon Spooner I think said he uses 1 Device for himself from time to time.

I use a similar thought pattern to Eric .

Using say supination resistance to help determine the stiffness of device used.

Left and right getting different design features

 

Eric

Thanks for that. However, strictly speaking we have two things we are talking about here.

1. Tissue stress whereby you are treating symptoms by whatever means and modifying stress to the painful tissue

In this instance, there is no injury on the asymptomatic guide so how does one manage with an orthosis? You have responded by using the below approach.

2. SALRA which uses the location of the STJ axis for altering tissue load.

To my knowledge, the predictive nature of this approach has not be studied let alone validated and therefore one could argue has no evidence base to support. In addition, what happens when there is no deviation of the axis in the unaffected foot (let alone the affected foot) - what approach would you take with the orthosis now?

Similarly, your thoughts on peroneal function have some theoretical merit but nothing to support.

Finally, you got back pain and there may be many reasons for it - including that Rohadur orthoses were quite thick and, if you had them 3/4 length, you probably had a heel raise as well so form of leg length discrepancy. If that were the only reason to have the second orthosis (i.e. leg length balancing) one could simply provide a heel raise halving the cost to the patient. Devloping back pain may not be the case for everyone especially with more slimline devices / materials.

Trevor

 

Trevor:

It is interesting that you bring up the point about Subtalar Joint Axis Location and Rotational Equilibrum (SALRE) theory in saying that "To my knowledge, the predictive nature of this approach has not be studied let alone validated and therefore one could argue has no evidence base to support. In addition, what happens when there is no deviation of the axis in the unaffected foot (let alone the affected foot) - what approach would you take with the orthosis now?"

What approach(es) do you use, Trevor, that has been "validated" and has "research evidence to support it"? Can you offer any better theory regarding the kinetic function of the subtalar joint other than SALRE theory? How many of your treatment methods and theoretical approaches are "supported"? Please remember that regardless of which theoretical approach we use to treat patients, none of us has "validated" and "research supported evidence" to support all of what we do on a daily basis to treat patients.

Moving on, in Tissue Stress Theory, the goal of foot orthosis therapy is not just to reduce pathological loading forces on injured structures, but also to optimize gait function and prevent future injuries from occurring.

Here is an excerpt from the chapter that Eric Fuller and I wrote 13 years ago on this subject:
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Using the Tissue Stress Approach in Clinical Practice

Several important steps in the clinical application of the tissue stress approach allow the clinician to efficiently and effectively treat the many mechanically-based pathologies which can affect the foot and lower extremity. First, the anatomical structure that is the source of the patient's complaints must be identified as specifically as possible. In order to do so, the clinician needs a detailed appreciation of the anatomy of the foot and lower extremity, including surface anatomical landmarks. Structures that are not easily palpable may be stressed utilizing specific clinical tests in order to determine the exact identity of the painful structure. These tests may include assessing pain production during manual pressure on specific anatomical structures, during muscular activity against resistance and/or during the passive range of motion of joints. Noninvasive and invasive diagnostic tests may also be necessary in many cases. The second step is to determine the structural and/or functional variables that may be the source of the pathological forces on the injured structure. Clinical data derived from a biomechanical examination of the foot and lower extremity-such as muscle testing, range of motion examination, and gait evaluation are all integral parts in understanding how pathological forces may be generated to cause injury in the individual. In addition, creating a model of the various structural and functional variables that may be affecting the stress on a specific structure will give insight as to how external loads may be altered in order to reduce the stress on a structure. These models may be either simple or complex; the more simple models often being sufficiently accurate to predict how clinical methods of treatment may mechanically affect the stresses on a specific anatomical structure. Third, it is necessary to formulate a mechanical and therapeutic treatment plan that will be most effective at accomplishing the following goals of treatment for each patient: 1) reduce the pathological loading forces on the injured structural components, 2) optimize overall gait function, and 3) prevent any other pathologies or symptoms from occurring. The appropriate use of the tissue stress approach allows the astute clinician to efficiently and effectively treat even the most difficult mechanical pathologies of the foot and lower extremity.

[From Fuller EA, Kirby KA: Subtalar joint equilibrium and tissue stress approach to biomechanical therapy of the foot and lower extremity. In Albert SF, Curran SA (eds): Biomechanics of the Lower Extremity: Theory and Practice, Volume 1. Bipedmed, LLC, Denver, 2013, pp. 205-264.]
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Using these concepts, I don't normally order just one orthosis for one foot. However, in specific instances, I will make just just one orthosis. These are as follows:

1. Unilateral amputee.
2. Patient that has lost or had one orthosis damaged.
3. Patient that requests just one orthosis for their symptomatic foot and understands that this may create limb length or other problems for them.
4. Patient has had a injury or surgery to one foot after they received their orthoses that has created the need for the injured/surgically corrected foot to be recast for a new orthosis.

As an analogy, I don't see many eye specialists ordering monocles these days for patients that have one "bad eye" and one "good eye". Routinely, these eye specialists make a pair of lenses that we call "glasses" which sit in front of both eyes, with the "bad eye" having more lens correction and with the "good eye" having less lens correction. In much the same way, I don't remember the last patient of mine over the past third-century that had one symptomatic foot with non-optimal gait function and with the other foot being symptomatic and having perfect gait function. In other words, I routinely attempt to mechanically optimize both feet of my patients with a pair of orthoses even if only foot is symptomatic.

Therefore, the choice for me as an ethical foot-health provider is obvious. I will advise patients that even if they have only one foot that is symptomatic, it will be in their best interest to have a pair of foot orthoses made, instead of just one orthosis. I tell them that in order to properly "balance" the limbs to optimize their gait function and prevent problems from occurring in the future for them, they will need both orthoses to allow me to improve the function of both of their feet, not just one. This approach has served me well for the last 33 years of practice in making foot orthoses for over 20,000 patients.

 

Kevin

Thanks for the response and some of the options for one orthosis did make me smile (in a good way).

I was by no means indicating that I have a validated model to assess and manage foot function and pathology. Like you, I use what evidence is available and, to a large part, my clinical experience. I too, rarely provide just one orthosis but I was interested on others thoughts and approaches to this example. In a percentage of cases, I use varying gait assessment tools whther it be inshoe analysis or other.

It was also driven a little, as I alluded to at the beginning of my post as to what criteria different clinicans use to determine the prescription they provide for the asymptomatic foot because in the past, when I have asked colleagues what factors they assess when performing a biomechanical evaluation, the response often requires a presenting complaint suggesting that the aspects assessed vary accordingly.

So perhaps my question should be, what factors do colleagues assess in the asymtpomatic foot when prescribing the orthosis?

Trevor

 

In the absence of a complaint, you have to have some way of predicting what structures are more likely to become injured for the particular patient in front of you. It is my expert opinion that STJ axis is one of those predictors. Another thing you could do is look at the impression of the sock liner of a well worn (and not shared) shoe. I've seen plenty of aysmptomatic feet with deep impressions under the first toe in the sock liner. There's another study that could be done. Correlation of location of deep impression in shoes with location of foot pathology.

If you looked for signs of impending pathology, and didn't see any, and you could even the "effective limb length" then I see no problem in giving the patient one orthotic. It would take more than the usual amount of thought given to a patient to overcome the usual and customary two orthotics.

Eric