Orthotic Prescription Help

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HI All

I am a student trying to figure out what to do with a petite active female patient in her early 20's who has: short first ray (very short!) and grade 1 HAV that is prominent, but reducible.

her rearfoot is rectus, and she doesn't appear to pronate too much, her COP moves through her 2nd toe, which is very long, but she toes off heavily on all lesser toes- evident by callousing and watching her walk.

she has a LLD of about 12mm and history of lateral ankle instability on her short leg (which I can understand)

mostly I'm wondering if a basic first ray function accommodation (morton's extension) would be enough to deal with the reducible HAV? Should I also be trying to invert the heel a little to redirect the STJ? and then stabilising lateral side and obviously adding a raise to the short leg...

TIA!

 

First and foremost, is she symptomatic?

 

Is the HAV and short 1st ray bilateral? If it's unilateral, is it this leg which is shorter, or the contralateral side?

 

only really the lateral ankle instability and she is worried about the progression of the HAV, which is understandable as she is so young.

the callousing on the ends of her toes is also something which might be nice to avoid in the long term

ultimately, as I am a student I need to ignore that part a little and say what could be done. in practise I'm not a fan of over prescribing orthotic therapy

thanks

 

bilateral, but is worse in the longer side I guess due to the greater pronatary force.

thanks

 

How recent and how serious is the history of ankle instability? What HAV grading are you using? I'm familiar with the Manchester scale in which grade 1 = no deformity.

(http://rheumatology.oxfordjournals.org/content/44/8/1061.full.pdf html)

 

Hi, thanks for the reply!

the lateral ankle instability was worse in the past and she achieved good results using wobble board however when playing touch footy (now) she still experiences 'rolled ankle', occasionally which she feels may be due to soft (damp ground) or uneven surface- she doesn't have issue when track or road running. I thought it may also have something to do with change of direction/stop/starts in the game. The ankle issue is usually on the short side, but affects both. She did do it this week it seem pretty mild, not even a limp. I guess it's remarkable as she is falling over...?

I forgot to say she is currently having some shin pain with her running (but not touch footy) and in the past has had tibial stress # on the short side. The stress # rehab included tib post strengthening but was some time ago (>2y). She feels this pain is due to her returning to running after a break and it is not present at walking pace. Not sure if there are any clues in there.

Re the HAV, I was looking at a Root et al description in Valmassey but should be using the Manchester scale, thanks so much for the link and the reminder. I guess it's stage two. The bunion area seems more like a stage 3 however (maybe due to a huge 1/2 ID space) her hallux is not touching 2nd. He 2nd met and hallux are pretty short so that may affect the 'reach' to the 2nd toe? Clearly, I haven't seen enough feet, especially young ones, to really know, sorry.

thanks again for you help

 

Based on the abnormal 1st/2nd rays you are describing, and the literature on hallux valgus/foot orthoses which I'm aware of, I'd have thought that trying to prevent progression would be experimental. Maybe a Morton's extension would help in reducing progression, but it would also affect function in the foot. Is it worth doing that if there are no symptoms?

With regard to the lateral instability - I'd recommend using a sports type ankle brace to resist inversion injuries, when she's playing sport.

In terms of foot orthosis, does she already have something to equalise the 12mm LLD? If not, I would probably just provide a heel raise. This isn't supposed to sound like an 'expert opinion' by the way, just my opinion. Thanks for raising the discussion.

 

From your other posts, the problems are the HAV and the lateral instability. Some pointers for a student. You should always address the reason that patient came to see you. That is a question that you ask the patient. Sometimes it's lateral ankle instabiilty, and others it's because my mom brought me. (At that point it is important address the Mom's concerns).

Next point. If it is a biomechanics related problem you need to figure out what is the biomechanical cause of the problem. Why is this patient having lateral instability. There is no evidence that limb length discrepancy causes supination or pronation. You can have a short leg that pronates or a short leg that supinates. Is there normal peroneal muscle strength. What is the transverse plane position of the STJ axis, and is there a large amount of forefoot valgus?

You should learn more about the center of pressure plot. It is a plot of the location of center of pressure over time. When the path exits through a toe that only means that was the last toe to leave the ground. The last toe to leave the ground can vary, within an individual, from one step to the next. Did someone tell you this was important information?

What do you mean by "she toes off heavily" with her lesser toes. Is this the cause of the calluses at the tips of her toes? Are her toes gripping in gait? Is she supinating a lot at toe off?

If you are going to treat HAV mechanically, you should have a theory on what mechanically causes HAV. If you think it is hypermobility of the first ray, reread that explanation and then try and explain it to me, because it makes no sense. (It's ok to question what you were taught.) Now, if you believe that HAV is caused by reverse buckling from the structures that make up the windlass mechanism then you can attempt to reduce the forces in the windlass mechanism. A Morton's extension would make the bunion worse if you are a believer in the windlass buckling theory.

Most of the time you do want to increase STJ supination when you have HAV. However, you also have lateral ankle instability. Increasing STJ supination in the face of lateral instability might make the lateral instability worse and the patient might get peroneal fatigue or tendonits.

What do you think "stabilizing the lateral side is?" I don't know what that means. You should read the thread here on the arena about maximum eversion height. In google type podiatry arena: maximum eversion height.

Eric

 

If you believe that orthotics can change the causes of HAV and you want to prevent HAV, how is that over prescribing?
Eric

 

Where is the shin pain? Can you reproduce it? Can you reproduce it with muscle testing? One cause of lateral ankle instability is a laterally positioned STJ axis. People with lateral axes will often get peroneal fatigue or pain when they run and walk. Some only when they run. Are you familiar with Kevin Kirby's rotational equilibrium paper. That would explain why a lateral axis can cause peroneal pain.

Eric
Eric