How to prevent that blister?

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hi all,
I was training in uni clinic. Had a pt. with blisters on the medial arch area (centered/medial/plantar aspect) of both of his feet (everytime after about 20 min. run).

He's been to a couple of podiatrists before but the orthotics seems to still give him blisters.

His feet sweats quite a lot and have a history of eczema.

BMX examination;

fully compensated RF varus​

FF suppinatus​

left foot pornates more than right (WBring and non-WB)​

functional hallux limitus​

Just wondering what modifications i should apply on his prefabricated orthotics and what materials should the cover be.

Are there any chemicals that can prevent blister as well?

cheers

 

Spenco top cover

 

First up I'd have to say watch out for that "pornation" you can catch social diseases if you are not careful......I spent 20 yrs trying to solve fit/friction/blister/pain issues in bushwalking boots...usually they are friction between foot and boot, you rarely see people with blisters if all they are wearing is sox.
First step check foot type joint roms and axes and decide if you have anything out of the ordinary.
If not it's probably solvable by finding a shoe/boot that actually fits the foot and using two layers of sox, maybe polypro liner to keep moisture off skin etc.

Feet with high transverse plane motion component or feet that change shape a great deal between weighted and unweighted are far more likely to be a problem in shoes or boots because they inherently generate more shear stress between foot and footwear. Generally speaking the heavier and stiffer the footwear gets the more severe the problem

Reducing shear can be done by getting the foot stabilized first then using all the shear reducing strategies like two sox, various options of special sox, material padding that has shear built in like the silipos gel lined sox, neoprene/spenco, prosthetic socket liners etc.... someitmes I make butterfly shaped fillers to fill in voids around narrow calc/archillies regions, a real problem in Aus is getting shoes wide enough in the mets and narrow enough in the heels.

Plantar blisters are usually undue abnormal plane motion rather than a neat sagittal plane motion...sometime the shape of the orthosis is the problem...too steep...too slippery...not slippery enough...too narrow ...too wide so the shoe can't take up around the rear half of the foot enough.
Fucntional hallux limitus tends to increase transverse motion...have you plantarflexed the 1st ray enough?....have you added enough lateral column support as well as medial , from my perpective a very common problem......just thinking out loud for you
Regards Phill

 

Have the patient wear white polyester socks.Have pt apply a thin layer of petroleum jelly to said area and cover with a bandage(a light one).This may help as the blisters are usually caused by friction.

 

When I said "all they are wearing is sox"....I meant no boots...it was a bit of a joke.
Old bushwalkers trick is two pairs with a good rubbing of soap over the inner sox around where the problem is.
Phill

 

http://www.ivillage.co.uk/dietandfitness/getfit/injurehab/qas/0,,257_159300,00.html



I'm not sure if this site is reliable but it says not to double your sox?

is Thor-lo a polyester sox and what other brands of polyester sox are out there?

cheers

 

I was an outdoor education teacher/ski instructor in a past life and have worn two pairs of soxs for over 30yrs in conditions as bad as they get for up to 16 days without access to indoor civilization....all I can say is 2 prs of sox works great if thats the way you bought your boots.
I have used all sorts of fibres from cotton liner sox under wool most of the year in temp ranges from 40 deg C down to -23 Deg C. I have never had a blister in any of these boots.. More recently the moisture wicking fibres that are tubular fibres with "capillary" type actions like polypropylene and some of what Thorlo make are great in wet conditions. I find they wear out much faster than a good felted up thick wool sock but they do help keep your skin drier. I have used Peter Storm Chlorofibre (one of the best I think) Heli Hansen, Devold, WIGWAM, Thorlo, X socks and many others of various thicknesses all of which work if you fit your footwear properly.
In respect to Thorlo, I sold a swag of them in my shops....but they do use more different fibres than you can poke a stick at so read the label to be sure what a particular sock is made from.
Polyester is just the grab bag low tech name a bit like "metatarsalgia" being a specific diagnosis....just not correct enough to identify a particular fibre.

Regards Phill

 

Thank you for your expertise, Phill, this is great info!

 

FF supinatus is the key here.

Put your typical device under a foot that has a FF supinatus or varus, and the 1st MPJ is not grounded, and hence most of the GRFs at early heel-off to FF load is focussed on the blistered area.

This supinated FF is a dilemma from me when issuing devices. On one hand we want to provide the forces via the orthotic, yet something doesn't look right when that 1st MPJ is in the air and the device is pushing into that MLA.

My advice would be to flatten the arch some how, and try to provide the therapeutic forces more distally about the sus-tac-tali? IF as we are taught, that this supinatus gradually corrects itself, then you can gradually build up the MLA, but by this time, it wont be this uncomfortable fulcrum.

 

Hi Atlas,
Nothing wrong with what you say but in practice I think the less rigid ones do tolerate the shape usually...(I tend to see it as a mid foot lift rather than "MLA" so I am trying to plantarflex all the metatarsals to some extent not just the first...)....at least the ones I make, and I often add a lateral forefoot wedge to even more forcefully bring the fisrt ray down and for the more rigid ones I don't....seems to work usually. I agree that if you focus too much force over too small an area tolerance will be a problem
Phill

 

What about this idea that goes against all conventional accepted wisdom?


Put a forefoot varus post in initially. (I can feel the ghost of Payne wince).

I realise that a FHL is present...and I know that plantar-flexing the 1st ray reduces the FHL. But for those that cringe at a FF varus post, am I that wrong in postulating that this 'sin' could act as some from of rocker-sole that would not demand that the 1st MPJ dorsiflex as much during ambulation.

This is my theory as to why, in the past, when it was more commonly used, that the FF varus post did not result in the horrific sequale that we predict now.


Just a weird thought.


The theory of fixing FF supinatus by just inverting the rearfoot? I don't know. Davis's law better be right. IMO, the human body sometimes wants Z-S-H-A rather than Z-A straight away.

With a supinatus or varus (and I don't think the distinction is as great as what is accepted), inserting a mild FF varus post with the more moderate RF varus post is not too much of an error. If you think about it, the net affect is still more midfoot pronation anyway, which is acting against the inverted FF position.

And in particular with this patient presentation, you are spreading the contact throughout a greater area of the foot, AND, you are reducing the height of the arch.

As time goes on, the severity of the 'evil' FF varus wedge can be ground down to the point of removing the thing.


Obviously this weird unpopular theory relies on my assumption that the rocker bar effect reduces the demand of 1st MPJ dorsi-flexion. It might work for this patient when all else has been tried...who knows?

 

My local running shop carries this stuff:

more info at: BodyGlide
Some of the distance runners I see use it religiously. Haven't tried it myself, but then again, I'm not prone to blisters!

 

zendjudo just a clarification "prefabricated orthotics" meaning off the shelf (OTS) or customised casted devices.

mark

 

Thank you for this, Mark.

 

I have read all the replies to this posting but it seems no one has pointed out the obvious (i.e. time for everyone to start seeing the forest instead of looking at the trees): try making some custom foot orthoses for this patient that actually match the morphologic contours of the patient's medial longitudinal arch and then you will probably see the blisters magically disappear.

How much longer are you going to subject this patient to an ill-fitting over-the-counter orthosis and their common problem....medial arch blisters!! Come on, you are a podiatrist. Make the patient some custom orthoses that match the shape of their foot so you can quit fooling around, wasting the patient's time and your time with a obviously poorly fitting pre-made arch support.

Time to step back and give a little analogy to drive the point home:

If a reasonable layperson was asked the following, how do you think they would answer?

A person bought over-the-counter eyeglasses and kept getting headaches every time he used them, what should he do??

If the layperson had good common sense then he would say: Go see your eyecare professional and get measured and fitted for a pair of prescription eyeglasses, that will take care of your problem.

Why do some footcare professionals have such a difficult time seeing the obvious and saying this to their patients??!!:

Let me measure you and fit you for a pair of prescription foot orthoses, that will take care of your problem!!!

 

Have done as as you suggest Atlas in rare circumstances where I thought it was necessary and would not be accused of overservicing due to the extra contact required.....you are right but I don't think it's often needed.
Regards Phill

 

Blisters

A new technology for reducing shear and friction forces on the skin: implications for blister care in the wilderness setting.
Wilderness Environ Med. 2006 Summer;17(2):109-19.

 

Hi guy's I'm new to this great forum and have found it very helpful so far. In response to the original question - I too have had difficulty with a pt blistering on one foot in the same area. The clinical picture is pretty similar also,

The pt has ligament laxity to both feet and medial deviation of the subtalar jt L>R, There is hyperpronation RCSP frontal plane dominant with a fair amount of transverse plane deformity. The pt has had left sided problems to gastosoleus and knee, and I have got him back to 80% ( when he came to see me he was struggling big time ) with simple insole, extrinsic posting and mid foot saddle, I decided to move for a 3/4 length high density eva device with 5mm medial heel skive 20mm deep heel cups and a full length low density eva cover, for durability.

Unfortunately he has tried a few runs and keeps getting blistering to the L ft only in the MLA area, Any advice appreciated, I feel I may have to try to control the transverse plane motion more? Anyone in aggreeance or have any ideas?

cheers guys!

 

Wholeheartedly agree with Kevin; why overlook a seemingly simple aetiology?

In any case, a slight variation on John's comments - place a layer of zinc-oxide tape over the site and cover it with petroleum jelly. Works well in most footwear, unless the shoe upper has been grossly deformed by fatigue. Make sure you wear black socks.

Jair

 

Barty,
I tend to think if you have a fair bit of transverse plane motion reange at the mid tarsal jnt you won't get it stabilized well using an EVA device, just too flexible. I usually use a plate type with a fair degree of lateral column support. The other very effective last resort for plantar blistering is the gel socket liner material used by prosthetists, 3 or 6 mm thick make sure you get the stuff with fabric bonded to both sides because you can't glue it to anything otherwise.
regards Phill

 

Efficacy of a new blister prevention plaster under tropical conditions.
Sian-Wei Tan S, Kok SK, Lim JK.
Wilderness Environ Med. 2008 Summer;19(2):77-81.

 

Zenjudo

I think what Kevin K said is very good advice. (so is the sock advice as a back up) I see quite a few sportsmen and long distance walkers and I can't remember anyone suffering from blisters. I fit custom / bespoke orthoses 90% of the time and only use OTC (usually Vasyli) if they can't afford bespoke or if the condition really only warrants a minor adjustment that can be done quickly and easily with OTC.

Atlas wrote

I regularly use a varus post full width but at the same time put in a lowered 1st ray. This is with Amfit EVA CAD CAM but you can do similar with casted and cast with a plantarflexed 1st ray and 2-5 varus post. As Atlas said You can also use an extrinsic post and grind it off if you find the forefoot suppinatus drops out.

Cheers Dave. BTW whats your real name?

 

Could it be a contact allergy?