I am about to start the first phase of a research project into the
permanence of kinetic and kinematic changes caused by foot orthotics in
a pronated population. Methods have been accepted but I would like
additional opinions on one.
The period of adaptation to foot orthotics and test shoes has been set
at one month. Data will be collected at beginning and end of that time
period. However, I cannot find studies to support any specific period
as being required for human adaptation.
Cavanagh has some work where he postulated lack of orthotic effect was
due to subject adaptation. There has also been work related to GRF and
surfaces that posutlates adaptation resulted in minimal GRF changes
although stiffness of surface material changed substantially. In all
cases adaptation was immediate.
Orthotists I contacted advised a 1-2 week period for their patients to
adapt to new foot orthotics. But their concern is to slowly build
patient tolerance to a point the orthotics can be worn all day.
So I would like to ask for advice, opinions and support about what is a
reasonable time for adaptation if the purpose is to determine whether
immediate kinetic and kinematic effects are indeed permanent or
temporary. Data collection at beginning and end of period is in test
shoes w/foot orthotics.
Thanks for your help, of course all answers will be posted to the list.
Louis B. Rosenfeld
Thank you all for your helpful replies. In general replies ranged from
instantaneous or nearly so if interested in only kinematic and kinetic
changes. Many respondents considered my posting to include wearability
or comfort adaptation and modification to soft tissue and bone. Those
answers generally acknowledged a one to two week break-in period during
which users should slowly increase wear time until able to comfortably
wear devices entire day. If during this break-in pain developed, then
wear should be immediately stopped, and the devices modified by the
maker. Some respondents felt there may be bone modification over a
several month period, but were unable to provide support.
A brief compilation of all replies is included below. If you would like
more information or to discuss this further please don’t hesitate to
contact me.
I don’t know about orthotics, but with AK & BK amputees (5-10+ years
post amputation) most of them adapt to drastic changes in alignment
after walking 30 feet down the hall and back.
Greg Rash
The small changes or lack of statistical differences that you have seen
in the literature in GRF and in kinematics are usually due to lack of
statistical power associated with a very small number of collected
trials and lack of controlling individual variability. Since you have
all the orthotics literature, read carefully the study by Eng and
Pierrynowski published on JOSPT (I believe 1995 or 6). They address this
problem and collected data from 30 strides. Since your work is dealing
with pronation take a look of a recent article that I published on Gait
and Posture (1997, 6:177-185). You might find it very interesting.
Nick Stergiou, Ph.D.
Nick_Stergiou/COE/UNO/[email protected]
I think it depends on what adaptions you are expecting. For example, I
can’t see that bone would change appreciably inside of 6 weeks. Muscle
strengthening studies seem to indicate that the first 4-5 weeks of a
strengthening programme may show a change in function (i.e. improved
test-retest ability) but no change in muscle physiology (same number and
size of sarcomeres).
Rod Whiteley
Mitchell & Whiteley Physiotherapy.
Rod Whiteley
an insert are made within the first few steps, but first reactions (as
indicated) to an insert may take weeks. Perhaps you could follow one or
two subjects with a very tight schedul over hours and days to get an
idea. If not possible, a personel comment (yes, I agree, I feel
comfortable now after x weeks) might help.
Alex Stacoff
Alex Stacoff
You first need to realize for each patient group( Dx ) there are
personality issues one must consider as well. The most pressing
criteria for the length of the recommended wean-in period is “does the
need to provide rapid orthotic intervention outweigh the need for the
patient to have a comfortable and successful initial use period arising
from a thoughtful adaptation period?”
Pat
As for the break in period, I follow exactly the same time you’ve
outlined. I encourage clients to slowly get used to the foot orthoses (2
-3 hours 1st day until full daily use over a 10 day to 14 day period)
and then wear them all the time if footwear allows.
Cameron Renwick, C.O.
Algonquin Orthopaedics
So many variables 10year olds 30 vs 70 Rigid orthotic vs smi or soft
rigid foot vs flexible, job, weight type of shoe and degree of
deformity??? Studies of this type are difficult Good luch but I tell
pts to use their commen sense as long as they are not insenstive ie
Diabetics
Currently there is no data or studies on the time it takes to adjust to
the use of orthotics. As a
certified athletic trainer, I concur with the information that the
therapists has given you that it take from about two weeks to one month
for most people to “adjust” to orthoses, although some people never do.
Marie Hornyik
