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Forefoot Varus/Invertus/Supinatus

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  #1  
Old 3rd February 2008, 02:58 PM
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Default Forefoot Varus/Invertus/Supinatus

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Following on from a discussion Kevin Kirby and I were having here:
http://www.podiatry-arena.com/podiat...ead.php?t=7773
we agreed it was a topic worthy of its own thread.

Such is my own fascination (and quest for greater understanding) of this topic I wondered if people would be willing to consider these questions for starters, and we can add to them as the discussion grows:

1. What do you consider a 'Supinatus' deformity to be?
2. How do you clinically deliniate between differing frontal plane deformities of the FF?
3. What orthotic posting/extensions/modifications (if any) do you prescribe at the FF and what is your rationale for doing so?

Looking forward to some responses

Respectfully,

Ian
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Old 3rd February 2008, 04:26 PM
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Default Re: Forefoot Varus/Invertus/Supinatus

Related threads:
Posting for forefoot varus
Is forefoot varus posting an anachronism?
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  #3  
Old 4th February 2008, 10:31 AM
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Default Re: Forefoot Varus/Invertus/Supinatus

Quote:
Originally Posted by Ian View Post
Following on from a discussion Kevin Kirby and I were having here:
http://www.podiatry-arena.com/podiat...ead.php?t=7773
we agreed it was a topic worthy of its own thread.

Such is my own fascination (and quest for greater understanding) of this topic I wondered if people would be willing to consider these questions for starters, and we can add to them as the discussion grows:

1. What do you consider a 'Supinatus' deformity to be?
2. How do you clinically deliniate between differing frontal plane deformities of the FF?
3. What orthotic posting/extensions/modifications (if any) do you prescribe at the FF and what is your rationale for doing so?

Looking forward to some responses

Respectfully,

Ian
The term "forefoot supinatus" implies that the forefoot needs to have an inverted forefoot deformity to have a soft tissue contracture that holds the forefoot more inverted during non-weightbearing exam than it normally would be . This certainly is not the case. A more inverted forefoot to rearfoot deformity may occur over time even in those feet that have a forefoot valgus deformity.

As the foot experiences increased subtalar joint (STJ) pronation moments during weightbearing activities, the medial metatarsal rays will be subjected to increased dorsiflexion moments and the lateral metatarsal rays will be subjected to decreased dorsiflexion moments. Over time, this increase in STJ pronation moments will tend to cause a lengthening of the plantar ligaments and medial fibers of the central component of the plantar aponeurosis and a shortening of the dorsal ligaments in the medial longitudinal arch. As a result, the influence of increased STJ pronation moments occurring over time during weightbearing activities will tend to cause the following:

1. An increase in inverted forefoot deformity.
2. A decrease in everted forefoot deformity.
3. A change in everted forefoot deformity to either a perpendicular forefoot to rearfoot relationship or to an inverted forefoot deformity.

Therefore, because of these mechanical factors that occur over time, I don't believe we can ever know how much forefoot to rearfoot deformity is "congenital" and "acquired" due to the dynamic, and ever-changing, nature of forefoot to rearfoot relationships. We are currently just guessing about how much of the forefoot to rearfoot relationship is due to "overpronation" or is the cause of "overpronation" when we examine a foot during non-weightbearing circumstances.
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Last edited by Kevin Kirby : 4th February 2008 at 10:55 AM.
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Old 5th February 2008, 03:20 AM
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Default Re: Forefoot Varus/Invertus/Supinatus

Hi Kevin,

It is a shame this thread does not seem to have yet generated the interest or responses we had hoped it would!

Quote:
Originally Posted by Kevin Kirby View Post
The term "forefoot supinatus" implies that the forefoot needs to have an inverted forefoot deformity to have a soft tissue contracture that holds the forefoot more inverted during non-weightbearing exam than it normally would be . This certainly is not the case. A more inverted forefoot to rearfoot deformity may occur over time even in those feet that have a forefoot valgus deformity.
By what mechanism could an inverted FF deformity occur over time in a foot with a FF Valgus deformity?

Ian
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Old 5th February 2008, 06:25 AM
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Default Re: Forefoot Varus/Invertus/Supinatus

Ian

Quote:
1. What do you consider a 'Supinatus' deformity to be?
2. How do you clinically deliniate between differing frontal plane deformities of the FF?
3. What orthotic posting/extensions/modifications (if any) do you prescribe at the FF and what is your rationale for doing so?
1,2) Pretty much agree with how Kevin describes but are there any long term studies that would imply this to be the case?

3) Personally I take into consideration the stiffness of the supinatus. If it easily flexes to the level of the rearfoot I tend not to post. **If it is also compliante then to GRF in late stance I might think about posting medially but I have found this is often uncomfortable for the patient. If it is not flexible then I tend to post. If the supinatus is stiff but the 1st ray is flexible and the 1st mPJ plantarflexes below the lesser MPJs I tend to post 2-5 or full width with a 1st/ray or 1st MPJ C/O, often with an extended post 2-5 to sulcus. At review I assess the supinatus, which has often reduced and remove the post accordingly and reassess the gait and posture.
Using my Amfit CAD CAM system EVA orthoses can easily be posted under the MPJs in any configuration for so called propulsive controll.

NB** I recently injured my left 2nd 3rd mets by accidentally kicking the corner of a wall during Brazilian Ju Jitsu (spinning over the head into an arm bar). I have a bit of a supinatus and a compliant 1st ray but I have never posted my orthoses.
However the only way to relieve the pressure on my very painful MPJs I had to add temporary felt medial post to sulcus with c/o. I was suprised that this seemed to increase pronation at propulsion and severely increased pressure sub 1st MPJ (as intended I suppose) but it seemed that my foot was determined to pronate thru the post if possible. = quite uncomfortable for long term and in that week my med glute, hip, ITB and ant tib/peroneals really ached after walking short distances EG < 1 mile. MPJ pain still there but pad removed and now no lateral leg pain, which was becoming the greater of two evils.

Cheers Dave
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Old 5th February 2008, 06:32 AM
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Default Re: Forefoot Varus/Invertus/Supinatus

Hi Dave,

Thank you for your response. Do you ever plantarflex the 1st Ray during capture of the negative cast? (i.e. 'cast out' the invertus deformity)

You mention you assess the supinatus at review - It is a point I supoose I generally have not considered previously - but with the concept of it being a dynamic principle as Kevin says, and appreciating it is adaptation of soft tissue it makes perfect sense. How often would you assess this? At each visit? What do you feel would be an appropriate margin of time for change to occur?

With thanks

Ian
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Old 5th February 2008, 07:29 AM
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Default Re: Forefoot Varus/Invertus/Supinatus

Ian

When posting the forefoot I personally like to look at the COP in the foot - either by using F-scan or looking at shoe/insole wear patterns. I will then link this with symptoms - standard stuff - however due to the long lever arm and potential moments of a fore foot post, I am careful that I don't create problems in the more proximal structures - similar to what Dave has experienced.
My approach with any forefoot alignment is therefore to ignore them as a single entity and to link them into the bigger picture.
Re forefoot positions, the most common one that see in clinic is the forefoot equinus or plantarflexed forefoot on the rearfoot. This seems to increase any frontal plane problems as GRF occurs earlier in gait and the tissues are then overloaded. Coincidently, the midtarsal joint seems to show more transverse plane orientation in these foot types - I have always assumed that this is due to a similar mechanism as Kevin outlined in the forefoot supinatus - soft tissue contractures and lengthening - as the midtarsal joint abducts to allow body weight to transfer smoothly through the foot.
Thankfully the treatment via orthoses for these patients is usually simple and effective.

Hope this makes sense
.
Phil
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Old 5th February 2008, 09:29 AM
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Default Re: Forefoot Varus/Invertus/Supinatus

Quote:
Originally Posted by Ian View Post
Hi Dave,

Thank you for your response. Do you ever plantarflex the 1st Ray during capture of the negative cast? (i.e. 'cast out' the invertus deformity)

You mention you assess the supinatus at review - It is a point I supoose I generally have not considered previously - but with the concept of it being a dynamic principle as Kevin says, and appreciating it is adaptation of soft tissue it makes perfect sense. How often would you assess this? At each visit? What do you feel would be an appropriate margin of time for change to occur?
Usually I do when taking a PoP cast but I don't ask for any lowering or cut out of the 1st ray. This does not always remove the supinatus tho. Whereas the weight bearing Amfit scan will if it is flexible or compliant enough to GRF. If not a forefoot post is automatically captured.

I usually review as standard 6 weeks - 2months after fitting. I apply the same principle to l.l.d. Functional l.l.d. often drop out and so I remove heel lift bias.
If I change anything at review I usually review again at about the same intervals but alter as I see necessary. If everything is ok and I do not alter anything then thats it, end of. Intervals are entirely based on experience and I always advise to return if any adverse symptoms appear, which fortunately is very rare for me.



Dave
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Old 5th February 2008, 10:36 AM
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Default Re: Forefoot Varus/Invertus/Supinatus

Quote:
Originally Posted by Ian View Post
By what mechanism could an inverted FF deformity occur over time in a foot with a FF Valgus deformity?

Ian
For example, a patient is examined and found to have a forefoot to rearfoot relationship during nonweightbearing examination that is in a 2 degree everted position (i.e. 2 degree forefoot valgus deformity). Then, 6 months later, the same patient comes in to your office and says for the last 3 months they have developed increased pain and swelling in the medial ankle area. MRI examination confirms a partial tear in the posterior tibial tendon. Measurement of the forefoot to rearfoot relationship now shows a 3 degree inverted position (i.e. 3 degree forefoot varus deformity).

How, Ian, did this 5 degree increase in varus forefoot deformity occur over 6 months time in this patient? Propose a mechanism by which this event could likely occur given the known time-dependent load-deformation characteristics of ligaments and tendons.
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Old 5th February 2008, 12:18 PM
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Default Re: Forefoot Varus/Invertus/Supinatus

Hi Kevin,

(I'll give this my best shot...)

It would be my assumption that following a PTT partial tear the patient would (1) Lose the ability to eccentrically control pronation moments (following heel strike in gait) and (2) have increased pronation moments across the STJ axis as a result of the reduced ability of the PT muscle contraction to supinate the foot.

Over time this would result in shorterned/contracted soft tissue dorso-laterally and lengthened/elongated plantar tissues/ligaments medially (Davis' law of soft tissue adaption). The consequence of this over a 3-6/12 period being an inverted FF attitude (supinatus deformity) when examined non-weightbearing.

However I suspect I have completely the wrong end of the stick and you meant what caused the increased tensile loading force in the PTT in the first place???

I await your critique (and hushed sniggers...)

Respectfully

Ian

Last edited by Ian G : 5th February 2008 at 12:48 PM. Reason: Typo
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Old 5th February 2008, 07:31 PM
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Default Re: Forefoot Varus/Invertus/Supinatus

Quote:
Originally Posted by Ian View Post
Hi Kevin,

(I'll give this my best shot...)

It would be my assumption that following a PTT partial tear the patient would (1) Lose the ability to eccentrically control pronation moments (following heel strike in gait) and (2) have increased pronation moments across the STJ axis as a result of the reduced ability of the PT muscle contraction to supinate the foot.

Over time this would result in shortened/contracted soft tissue dorso-laterally and lengthened/elongated plantar tissues/ligaments medially (Davis' law of soft tissue adaption). The consequence of this over a 3-6/12 period being an inverted FF attitude (supinatus deformity) when examined non-weightbearing.

However I suspect I have completely the wrong end of the stick and you meant what caused the increased tensile loading force in the PTT in the first place???

I await your critique (and hushed sniggers...)

Respectfully

Ian
Ian:

You basically answered the question correctly. However, when I said "time-dependent load deformation characteristics of ligaments", I was specifically referring to stress relaxation and creep of ligaments, both of which are time-dependent properties common in viscoelastic substances, such as ligament, tendon, cartilage and bone.

If there was a posterior tibial (PT) tendon tear, the PT muscle/tendon complex would weaken which would decrease the ability of the patient to generate an internal subtalar joint (STJ) supination moment. As a result, the foot would tend to pronate more at the STJ which, in turn, would increase the ground reaction force under the medial metatarsal heads. This would cause increased medial metatarsal ray dorsiflexion moments, increased tensile forces in the plantar ligaments and decreased tensile forces in the dorsal ligaments of the medial column during weightbearing activities. As a result, over time, the ligaments plantarly that are being stretched more will elongate and the ligaments dorsally that are being stretched less will shorten. This will cause an apparent dorsiflexion deformity of the medial metatarsal rays, relative to the lateral metatarsal rays which will, in turn, cause an increase in an inverted forefoot to rearfoot position during non-weightbearing examination than before the PT tendon injury occurred.

Ian, how might you then best design a custom foot orthosis to try and reverse this "forefoot supinatus"? In other words, where would it make more sense to put increased orthosis reaction force on the plantar foot with an orthosis, given this mechanical scenario, if your goal was to reduce the inverted forefoot deformity in this patient over time?
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Kevin

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Last edited by Kevin Kirby : 5th February 2008 at 11:05 PM.
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Old 6th February 2008, 03:39 AM
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Default Re: Forefoot Varus/Invertus/Supinatus

Kevin,

Logic (well mine anyway) would suggest that to achieve this you would want to increase the plantar ORF on the lateral FF for example with valgus FF posting/wedging.

However applying this to our previous patient scenario I would be considering the increased pronation moment that this would cause around the STJ due to the long lever arm at the FF, so would likely issue varus RF posting, medial heel skives and in conjunction with appropriate PTT rehab

Look forward to your response

Ian
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Old 6th February 2008, 04:38 AM
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Default Re: Forefoot Varus/Invertus/Supinatus

Hi Phil,

Quote:
Originally Posted by Phil Wells View Post
Re forefoot positions, the most common one that see in clinic is the forefoot equinus or plantarflexed forefoot on the rearfoot. This seems to increase any frontal plane problems as GRF occurs earlier in gait and the tissues are then overloaded.
Rather than frontal plane issues do you not find more sagittal plane issues (restriction/blockade) with the FF Equinus foot type? Thought being that they use/lose some of their TCJ ROM just getting plantigrade and therefore have less available for ambulation (analagous with walking uphill?)

Respectfully

Ian

Last edited by Ian G : 6th February 2008 at 06:02 AM. Reason: Typo
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Old 6th February 2008, 10:30 AM
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Default Re: Forefoot Varus/Invertus/Supinatus

Quote:
Originally Posted by Ian View Post
Kevin,

Logic (well mine anyway) would suggest that to achieve this you would want to increase the plantar ORF on the lateral FF for example with valgus FF posting/wedging.

However applying this to our previous patient scenario I would be considering the increased pronation moment that this would cause around the STJ due to the long lever arm at the FF, so would likely issue varus RF posting, medial heel skives and in conjunction with appropriate PTT rehab

Look forward to your response

Ian
Ian:

If my goal was to design the orthosis to decrease the soft tissue contracture of the forefoot which resulted in the forefoot to rearfoot relationship being more inverted than normal, I would design the orthosis as follows:

1) increase the orthosis reaction force (ORF) plantar to the medial calcaneus to increase the external subtalar joint (STJ) supination moment, and

2) increase the ORF plantar to the medial longitudinal arch to increase the external STJ supination moment and increase the external medial forefoot plantarflexion moment. By placing ORF in the proximal medial arch, the ground reaction force in the medial metatarsal heads will be decreased which, combined with the increased ORF proximally, will increase the medial forefoot plantarflexion moment.

Both of these orthosis modifications would help increase the chance of the patient showing a gradual increase in everted forefoot to rearfoot relationship, or a decrease in inverted forefoot to rearfoot relationship, over time.
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Kevin

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Last edited by Kevin Kirby : 6th February 2008 at 05:35 PM.
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Old 6th February 2008, 06:01 PM
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Default Re: Forefoot Varus/Invertus/Supinatus

I have avoided posting in this thread as I have previously made my views known:
Quote:
Originally Posted by Admin2 View Post
However .... what about this situation:

What say a foot starts of its life as a classical and traditional flexible forefoot valgus. It compensates about the traditional longitudinal axis of the midtarsal joint, with a bit of oblique axis pronation as well (ha ha). Over time, the soft tissues adapt to the compensated position about the traditional long axis of the MTJ (ie a traditional forefoot supinatus has developed), BUT as the foot started out life as a traditional forefoot valgus, the traditional forefoot supinatus is relative to the position the foot started in.....the forefoot is perpendicular to the rearfoot, even though it is a traditional forefoot supinatus!
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Old 6th February 2008, 09:14 PM
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Default Re: Forefoot Varus/Invertus/Supinatus

Quote:
Originally Posted by Craig Payne View Post
I have avoided posting in this thread as I have previously made my views known:
However .... what about this situation:

What say a foot starts of its life as a classical and traditional flexible forefoot valgus. It compensates about the traditional longitudinal axis of the midtarsal joint, with a bit of oblique axis pronation as well (ha ha). Over time, the soft tissues adapt to the compensated position about the traditional long axis of the MTJ (ie a traditional forefoot supinatus has developed), BUT as the foot started out life as a traditional forefoot valgus, the traditional forefoot supinatus is relative to the position the foot started in.....the forefoot is perpendicular to the rearfoot, even though it is a traditional forefoot supinatus!
Craig:

Who ever said that tradition is a good thing??
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Old 7th February 2008, 07:54 PM
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Default Re: Forefoot Varus/Invertus/Supinatus

Quote:
Originally Posted by Ian View Post
Following on from a discussion Kevin Kirby and I were having here:
http://www.podiatry-arena.com/podiat...ead.php?t=7773
we agreed it was a topic worthy of its own thread.

Such is my own fascination (and quest for greater understanding) of this topic I wondered if people would be willing to consider these questions for starters, and we can add to them as the discussion grows:

1. What do you consider a 'Supinatus' deformity to be?
2. How do you clinically deliniate between differing frontal plane deformities of the FF?
3. What orthotic posting/extensions/modifications (if any) do you prescribe at the FF and what is your rationale for doing so?

Looking forward to some responses

Respectfully,

Ian

There two parts of the question: is it possible to measure forefoot to rearfoot accurately and how do you measure the changes in a foot over time. (changes like arch flattening.)

Forefoot to rearfoot is not a repeatable measurement. A few years back the CCPM biomechanics department tried to see if we all bisected the calcaneus the same way. There was a 5 degree range in the measurements. If you included students I'm sure that you would double that. The heel bisection is the easier part of forefoot to rearfoot measurment.

The long axis of the midtarsal joint is theoretical fiction that is convenient for describing motion but does not really have a basis in anatomy. The midtarsal joint is essentially a planar joint that allows an envelope of motion. Within that envelope of motion you can move the foot in such a way that the forefoot rotates around a longitudenal axis, but it does not have to revolve around this axis.

I think that you can load the lateral column to a relatively repeatable position, but the medial column could be anywhere. When you take the forefoot to rearfoot measurement do you plantar flex or dorsiflex the medial column? Do you just let the first ray choose its own position within its range of motion? For this reason I think that you would be lucky to be able to repeat forefoot to rearfoot measurement from one time to the next.

If there is anyone out there who thinks that forefoot to rearfoot is a repeatable measurement they should try the study and show the world. If I did it, I would be told that I wasn't doing it right.

Supinatus is essentially a flattening of the medial longitudenal arch. It's permanence will be related to whether or not the plantar ligaments are permanently lengthened. So, a standing arch height or a foot length measurement might be a better way to measure this than forefoot to rearfoot measurement.

What postings
I believe that there is something to what Root Orien and Weed taught about varus deformities. It is possible to run out of range of motion of the joints of the foot before the medial column hits the ground. Their idea of uncompensated varus. Trying to figure this out with non weight bearing measures is essentially impossible. However, if you just look at the foot when standing and try to make it evert then you can see if range of motion is available.

I measure the height of the foot off of the ground when everted and add an intrisic forefoot valgus post equal to that height or less.

Regards,

Eric
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Old 8th February 2008, 09:56 AM
Ian G's Avatar
Ian G Ian G is offline
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Default Re: Forefoot Varus/Invertus/Supinatus

Thanks for your answer Eric.

Out of interest how do you feel about FF Varus postings? Is there particualr situations when you feel they are important/beneficial or maybe situations where they are completely inappropriate in your experience?

Ian
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Old 8th February 2008, 04:55 PM
efuller efuller is offline
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Default Re: Forefoot Varus/Invertus/Supinatus

Quote:
Originally Posted by Ian View Post
Thanks for your answer Eric.

Out of interest how do you feel about FF Varus postings? Is there particualr situations when you feel they are important/beneficial or maybe situations where they are completely inappropriate in your experience?

Ian

They are essential in people who have lateral column overload/ sinus tarsi pain/ genu valgum and are unable to evert far enough to get significant load on the medial column without abductnig their tibia. I should also clarify what I'm talking about. I'm talking about something under the 1st metatarsal head and maybe the hallux depending on the shoe.

This is different from the classical Rootian intrinsic post which does not work for this condition because with an intrinsic varus forefoot post the arch of the orthosis will be very high and it will try and support the deformity by pushing on the arch which can be very painful.

Regards,

Eric
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Old 1st June 2010, 09:36 PM
flipper flipper is offline
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Default Re: Forefoot Varus/Invertus/Supinatus

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Originally Posted by Kevin Kirby View Post
Ian:

If my goal was to design the orthosis to decrease the soft tissue contracture of the forefoot which resulted in the forefoot to rearfoot relationship being more inverted than normal, I would design the orthosis as follows:

1) increase the orthosis reaction force (ORF) plantar to the medial calcaneus to increase the external subtalar joint (STJ) supination moment, and

2) increase the ORF plantar to the medial longitudinal arch to increase the external STJ supination moment and increase the external medial forefoot plantarflexion moment. By placing ORF in the proximal medial arch, the ground reaction force in the medial metatarsal heads will be decreased which, combined with the increased ORF proximally, will increase the medial forefoot plantarflexion moment.

Both of these orthosis modifications would help increase the chance of the patient showing a gradual increase in everted forefoot to rearfoot relationship, or a decrease in inverted forefoot to rearfoot relationship, over time.

I know this was posted a long time ago but would like to ask a few questions

1. If there was a large forefoot supinatus present, and therefore I assume a large amount of "compensatory" calcanial valgus and STJ pronation. Would by doing these orthoses modifications, potentialy raise the medial Metatarsal heads off the ground? If they were to raise slightly, would the correction be faster? (Maybe Im being a bit extreme but if the correction was enough then i guess it could happen)

2. Would we expect to see some raise in weight bearing arch height after continued use?

3. if the answer to no.2 is YES then does this mean orthotics can actually permanently fix (create arch) "Flat foot" now? Assuming it is due to a forefoot supinatus (which may or may not even exist)

Any response would be much appreciated.

oh and a 4th. If some one was to be born with a forefoot valgus, wouldn’t it be worth a shot at just leaving it until it levels between a FFvalgus and varus

Cheers
Nick
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Old 8th June 2010, 08:30 AM
Gareth Klepacz Gareth Klepacz is offline
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Default Re: Forefoot Varus/Invertus/Supinatus

I like to add a question: when using a forefoot varus extention, has anyone tried to extend under the toes (shoe dependent) instead of sub met heads only? I have used the latter in the past but have noticed when trying to use a higher angle (> 3 degrees) that they have a retrictive effect on the propulsion phase of gait and have wonderred if extending under the toes would get around this.

I have used forefoot varus posting ( up to 3 degrees) in the past and have found very effective in the right person.

regards

gareth
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Old 10th June 2010, 12:15 PM
efuller efuller is offline
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Default Re: Forefoot Varus/Invertus/Supinatus

Quote:
Originally Posted by flipper View Post
I know this was posted a long time ago but would like to ask a few questions

1. If there was a large forefoot supinatus present, and therefore I assume a large amount of "compensatory" calcanial valgus and STJ pronation. Would by doing these orthoses modifications, potentialy raise the medial Metatarsal heads off the ground? If they were to raise slightly, would the correction be faster? (Maybe Im being a bit extreme but if the correction was enough then i guess it could happen)
You are thinking in terms of positional or "deformity" biomechanics rather than force and moment biomechanics. A medial heel skive with a 15 degree wedge effect in the heel of the orthotic will not invert the heel 15 degrees. What it does do is change the location of center of pressure under the foot and then change the moment from ground reaction force. (In positional terms: it won't be pronated as hard.) I don't think I've ever seen a drvice that would lift the medial metatarsals off of the ground. Maybe a spike thotic would get the muscles to invert the foot.

See my post above about whether or not we can accurately measure forefoot to rearfoot.


Quote:
Originally Posted by flipper View Post
2. Would we expect to see some raise in weight bearing arch height after continued use?

3. if the answer to no.2 is YES then does this mean orthotics can actually permanently fix (create arch) "Flat foot" now? Assuming it is due to a forefoot supinatus (which may or may not even exist)
The device might slow the flattening. Medial arches will lower when the plantar ligaments become stretched. They will stretch in response to high loads causing a dorsiflexion moment on the respective column. To permanentlly raise the arch you would have to shorten the plantar ligaments which is quite unlikely if the patient is walking regularly.

Regards,
Eric
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Old 15th June 2010, 02:16 PM
james clough, DPM james clough, DPM is offline
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Default Re: Forefoot Varus/Invertus/Supinatus

I never post a forefoot supination, in any form, these can be casted out by dorsiflexing the hallux during casting or scanning. An elevated first ray will jam the first MTPJ and the jamming will result in further elevation of the first ray as the metatarsal cannot plantarflex with normal first MTPJ dorsiflexion. Prestressing the hallux in dorsiflexion, I find is a very reliable way to overcome functional limitation of motion of the first MTPJ and allow plantarflexion of the first met head to occur. This basically eliminates your forefoot deformity. I add this with all FF supination and functional hallux limitus.
Good rearfoot control of the foot will be necessary along with good contour of the device to the medial longitudianl arch, with the foot in the correct position, without any forefoot deformity in the cast. Anything under the first met head will serve to decrease motion of the first MTPJ and limit plantarflexion of the first metatarsal head, something we do not want to do.
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