09/13/2014    Carl Solomon DPM

Wrong Size Shoes Can Exacerbate Bunions: MA Podiatrist (Kevin Kirby, DPM)

Although Dr. Kirby's comments initially seem to
disagree with Dr. Kiel, his statements actually
support Dr. Kiel. Dr. Kirby qualifies his own
assertion that external forces cause Hallux
valgus when he states "...in susceptible
individuals". That suggest to me that external
forces do NOT cause Hallux valgus unless there's
a predisposition! And Dr. Kiel cites a perfect
example of the unilateral bunion deformity in the
patient who wears a pair of identical shoes.

I question that intermittent wearing of tight
shoes as a cause for hallux valgus can be
compared to application of continuous force over
time, as is done with clubfoot casting or Chinese
foot binding to cause structural changes.

Indeed it is multifactorial, and two of those
factors are spelled out: predisposition, and
external force. So in order to come to any valid
conclusion, a matrix of 4 variables needs to be
studied:

(+) Predisposition with (+) External force
(+) Predisposition with (-) External force
(-) Predispositon with (+) External force
(-) Predisposition with (-) External force

So in Dr. Kirby's own (paraphrased) words... as a
podiatrist, he should be very careful in stating
his position unless there is sufficient evidence
to validate his concept. His use of wording like
"strong liklihood", and anectodal statements like
"...it is well-known..." are at the very bottom
of the hierarchy of evidence-based medicine.

Carl Solomon, DPM, Dallas, TX, cdsol@swbell.net

Other messages in this thread:

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09/18/2014    Robert D. Phillips, DPM

Wrong Size Shoes Can Exacerbate Bunions: MA Podiatrist (Kevin Kirby, DPM)

In response to Dr. Kirby’s letter about wrong
size shoes, I would like to refer him to a
chapter that I wrote in the book, Hallux Valgus
and Forefoot Surgery, ed. Hetherington, 1994. In
this chapter I gave a very complete accounting
(up to that date) of the literature associating
hallux valgus with shoes. It is well
documented in the literature that hallux valgus
is approximately 10 times more prevalent in the
shoe wearing populations than in the non-shoe-
wearing populations of the world. One of the
most complete surveys was performed by Shine in
1965, in which he examined 88% of the population
of the Island of St. Helena, which at that time
was a closed genetic pool. In this study he
found the following: 1) Approximately 50% of the
population wore shoes on a voluntary basis. 2)
Men and women wore very much the same types of
shoes. 3) Bunions were much more frequent in the
shoe-wearers. 4) The severity of the bunions
increased with the increase in the number of
years that the person had worn shoes. 5) Even
when both sexes wore similar sensible, rounded
shoes there was still a marked increase in the
occurrence of hallux valgus in females compared
to males.

I’m not really sure what a “not-properly-fitting
shoe” is. Does it mean a shoe that is not the
proper length in the toes, or does it mean a shoe
that does not have the proper ball length, or
does it mean that the shoe is not wide enough, or
does it mean that the shoe is not made on a last
shape that fits the foot? The issue about
pointed toe shoes has been argued for over 100
years, with mostly opinion and few facts. Meyer
in 1905 did note that all shoes changed the
deviation of the hallux to the first metatarsal
from being in line to a mild degree of abductus
such that the hallux was forced into being
parallel to the 2nd toe. James in 1939 did more
to confirm this finding comparing feet that wear
shoes and those that don’t in different
populations. Morioka in 1974 followed this
finding up, showing the same change in hallux
orientation when Japanese forest workers changed
from traditional Japanese work footwear to
western style work footwear.

Few people would deny inheritance has an
influence in the development of the deformity, if
we assume that any foot type is hereditary. A
recent study by Pique-Vidal (2007) has a fairly
good look at 3 generations of probands presenting
for hallux valgus. They found that 90% of the
probands had at least 2 members in the family
also affected, so they concluded that the
inheritance pattern was likely to be autosomal
dominant. A closer look at their study showed it
was comprised of 93.7% women and only 6.3% men.
The question has to be asked whether this
represents a cross section of the population? 5%
of the patients were under age 21, so the
diagnosis of Juvenile Hallux valgus was made.
Other studies on hallux valgus, though indicate
that a great many people recognize the formation
of the bunion in their teenage years. I believe
that a study similar that of Shine’s of the cross
section of a closed genetic pool would be more
likely to truly identify the true inheritance
pattern.

I do not intend to further the discussion here,
however a number of studies do exist that show
that the foot functions differently in any shoe.
One example was Cavanaugh (1987) showing that the
duration of pronation of the rearfoot was longer
in shoes than out of shoes. I’m sure that Dr.
Kirby is well aquainted with the running
literature on barefoot vs. shod running and
differences in foot function between the two
states. The purpose of writing this response is
to remind us that it is important that we not
resort to trite statements about misfitting shoes
being the etiology or that it is just some type
of inheritance pattern. Change of foot function
in shoes is extremely important to realize,
however much more research needs to be done on
how various foot types change in different types
of shoes and also how various foot types (all
types) are inherited. The deformity has indeed a
multifactorial etiology and I’m sure that it will
yet be years before we understand enough to truly
take actions to prevent the problem from
occurring.

For those who desire my summary of 340 articles,
covering more than 100 years of literature on the
etiology of hallux valgus, I will be happy to
share such if you drop me a note.

Robert D. Phillips, DPM, Orlando, FL,
Robert.Phillips9@va.gov

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09/17/2014    Dennis Shavelson, DPM

Wrong Size Shoes Can Exacerbate Bunions: MA Podiatrist (Kevin Kirby, DPM)

Dr. Kirby discussing plastic deformation may be a
red herring because, clinically, we cannot
measure plastic deformation nor treat or reverse
its pathogenic properties.

There is consensus that we need a replacement
biomechanical paradigm that determines the
architecture of the open chain foot to replace
STJ neutral. That will enable us to do two
things.
1. Take better than STJ neutral casts
2. Better engineer feet in closed-chain a la Dr.
Kirby’s tissue stress or any other intratester
means

Shoes come in pairs, we don’t! 60% or more of us
have a limb length discrepancy with one foot
larger, wider and more collapsed. Asymmetry
within our biological structure is the main
reason why patients present with one sided
bunions as well as one sided ankle, knee and hip
complaints. This best explains Dr Kiel’s
oxymoron.

In Foot Centering theory, shoe fitting the larger
foot and early treatment of LLD are mandated
parts of the conservative and post-op
bunion/biomechanical treatment plan.

In Foot Typing, due to asymmetry, the SERM-PERM
Interval of our feet differs for most of us as
well. Bunion deformity predictably exists and
cascades faster on the side with the highest
Forefoot SERM-PERM Interval regardless of the
rearfoot type.

Finally, it is the rigid-flexible foot type with
a very low RF S-P Interval and a very high FF S-P
Interval that develops juvenile bunions most.
That’s why aggressive biomedical engineering
before, during or after the juvenile bunion
develops is mandated in Foot Centering Theory.

Dennis Shavelson, DPM, NY, NY
drsha@lifestylepodiatry.com