The Impact of Flat Feet Orthotic

By Mark Charrette, DC

In previous columns, I’ve reviewed the effects of abnormal Q angle and leg-length
inequality
on the pelvis and spine, as well as on the knee joints. I’ve
discussed the various symptoms and clinical problems reported by patients with
excessive pronation or sports-related injuries. This time, I want to call to
your attention to (or remind you of) an interesting study that demonstrated how
the lack of an arch can have a significant physiological impact. Orthotic 

It makes sense to chiropractors that abnormal foot biomechanics would result
in more difficult physical functioning. Intellectually, we can hypothesize that
not having an arch would make push-off less effective, since the foot does not
become the needed “rigid lever” at toe-off. This, therefore, would make walking
more inefficient and more energy-consuming. The end result would seem to be more
energy usage and greater fatigue than necessary from walking. On a gut level,
this concept feels right – but is it scientifically accurate?

A 1988
study1 investigated this subject
, and came up with some very interesting
conclusions. The results of this study are very important to chiropractors,
whether they treat a general practice or work with performance-based athletes.
Judge for yourself whether some of your patients who had not been considered for
foot orthotics might benefit greatly.

Energy Use and Flat Feet

The three researchers who wanted to investigate the above hypothesis came
from backgrounds in physical medicine, physical therapy, and rehabilitation.
Their stated goal was to perform a “comparative study … to assess the effects
of arch support on oxygen consumption.”1 The experimental subjects
were 40 women between the ages of 18 and 38 years. All women were in general
good health, with no foot or lower extremity complaints. From weight-bearing
X-ray measurements, 20 women were selected who met the diagnostic criteria of
flat feet. The other 20 healthy women were used as a matched control group.

Subject Testing

All subjects had several physiological parameters tested – at rest, while
walking on a treadmill at three levels of speed and incline, and after recovery.
The measurements included ECGs, systolic
and diastolic blood pressures
, pulse rates, and oxygen consumption. Energy
cost of walking was calculated by multiplying the milliliters of oxygen consumed
each minute by the weight of the subject in kilograms. This initial test
provided the baseline for all women in the study.

The 20 women with flat feet were provided with custom-made arch supports,
which they wore full time for two weeks. At that point, the same physiological
testing procedures were again performed on all subjects, with the experimental
group wearing their custom arch supports.

Results

The control group showed no differences in any of the measurements from the
first test to the second test. There was no change in the resting measurements
of the group wearing medial arch supports. This demonstrates the consistency and
validity of the measurements performed by the researchers.

Significant differences were seen in the walking and recovery measurements of
the experimental group (those wearing the arch supports). Their heart rates were
significantly slower, their systolic blood pressures were lower, their
consumption of oxygen was less, and their calculated energy cost was much less.
These differences were most obvious at the faster walking speeds and the higher
inclines, as could be anticipated.

Suitable Arch Support

A control group was used, since it was possible that re-testing two weeks
later might demonstrate improved performance because the subjects were more
experienced with the test procedures. In this study, the control group did not
show any significant change between the two tests. The significant improvements
in physiological performance in the experimental group can be confidently
ascribed to the use of the arch supports. The study’s authors stated that
“oxygen consumption can be decreased in patients with flat feet simply by
applying a suitable arch support.”

What is a “suitable arch support?” These researchers took weight-bearing
imprints of each experimental subject’s feet, made several measurements, and
built a support of the medial arch from polyethylene. They then inserted this
custom-made arch support into the leather of the shoe to prevent displacement.
So, in this study, these orthotics were built based on a “weight-bearing,
functional position” image of the foot.

Increased Performance

The large and significant differences between the two tests in the group
wearing arch supports should make us all think twice when considering the
benefits of orthotics in our patients. Whether a patient is a “weekend warrior”
or an internationally competitive athlete, an increase in performance can
generally be predicted when the flat foot is supported by a suitable
orthotic.2-5

When a patient complains of difficulty in walking, inability to stick to a
jogging exercise program, or even has generalized fatigue, it is our duty to
examine their feet for the presence of low or collapsed arches. A well-made
custom orthotic may be the simple and cost-effective solution to a physiological
problem.

Orthotics

References

  1. Otman S, Basgöze O, Gökce-Kutsal Y. Energy cost of
    walking with flat feet.
    Prosthets Orthot Intl,1988;12(2):73-76.
  2. Kuhn DR,
    Shibley NJ, Austin WM, Yochum TR.
    Radiographic evaluation of weight-bearing
    orthotics and their effect on flexible pes planus. J Manip Physiol
    Ther,
    1999;22(4):221-226.
  3. Stude DE, Gullickson J. Effects of
    orthotic intervention and nine holes of simulated golf
    on club-head velocity
    in experienced golfers. J Manip Physiol Ther,2000;23(3):168-174.
  4. Stude DE, Gullickson J. Effects of orthotic intervention and nine holes of
    simulated golf on gait in experienced golfers. J Manip Physiol Ther,
    2001;24(4):279-287.
  5. Hyland JK. Arch stability with spinal pelvic stabilizers. Practical Res
    Studies,
    2007;21(4):1-4.