Julia Ferry
EXS 350
“Understanding the Pain”
Ever wonder where that low back pain is coming from? Most people experience
pain and do not realize just where that pain is actually coming from. People look back on
the week and try to guess which activity it was that induced their episode of pain and
some have little success with this guessing game. Most people forget to look down - at
their feet. The human foot is an interact web of bones, joints, tissue, ligaments, tendons,
and arches. This web of support can be the cause for some of those low back pains, shin
splints, stress fractures, and slew of other issues. The foot is like a steady chain that is in
constant communication with other joints, like the knee and hip. Its arches offer up
support to the rest of the system and when they weaken problems ensure that can be
corrected by the simple addition of an orthotic support to one’s shoe. To understand this
system of arches and joints, orthotics and studies, one must understand the basic
mechanics of the foot.
The foot is comprised of 25 percent of the body’s bones, 26 bones in total; It’s
movement is designed to flex and roll as it absorb up to 1000 tons of force a
day(Townsend). The foot is the body’s main way of absorbing the force that is created
from a person’s mass, gravity, and propelling motion. In a runner’s heel strike the
calcaneus absorbs about 5120 pounds of relative force (Townsend). This force is largely
pushed through the foot’s three arches.
The foot has three arches, the medial longitudinal arch, the lateral longitudinal
arch, and the anterior transverse arch. These three arches form what is called the plantar
volt. One is not born with the plantar volt but it is developed around the age of six in
most children (Danchik). Each arch is situated in the foot specifically to help elevate the
body’s load. The medial longitudinal arch is the arch that is most visible in the foot,
located on the medial aspect. This arch consists of the navicular bone and is supported
mainly by the planter fascia and the spring ligament. On the opposite side of the foot is
the lateral longitudinal arch; this arch is mainly supported by the cuboid bone. The lateral
longitudinal arch is usually left out from many of the orthotic support but it is equally as
important as the other two arches in the plantar volt. The third arch that makes up the
plantar volt runs from the medial to lateral side of the foot. Because the anterior
transverse arch runs from the metatarsal heads back to the tarsal bones, when it weakens
there is often a build up of callous material under the metatarsal heads (Danclik). The
repeated falling of the arch or a disturbance of the interdigital nerves could indicate that
the arch is not getting support from the plantar fascia.
When the plantar volt lacks it’s needed support problems can then radiate up the
body, effecting the knees, spine, or hips. This occurs because approximately 50 to 60
percent of the body’s weight is supported by the plantar volt and with out the volt’s
proper support the forces can be abnormally concentrated and cause problems throughout
the body (Danclik). This degeneration of the plantar vault can cause clinical symptoms.
A typical way to correct this issue is to prescribe custom orthotics to the symptomatic
patient. The orthotics act as a support to the three arches so that during normal standing
the main force of the load, situated at the plantar volt apex, is fully supported. This way,
throughout a normal gait cycle the impact forces will be controlled (Danclik).
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But what is a normal gait cycle? The average walking gait consists of an
alternating stance and swing of each leg; while the right leg is in swing the left leg is in
stance and vice versa. In a normal gate the stance phase is about 62 percent while the
swing phase only occurs 38 percent of the time (class notes). Each of these two phases
can be broken down further.
The stance phase has five parts to it, the heel strike, foot flat, heel rise, push-off,
and toe-off (class notes). During the push-off and toe-off stage the foot experiences the
largest force, at nearly five times the body’s weight (class notes). This force is placed on
non locked joints (from the pelvis down through the knee) and even the slightest sway of
movement can disrupt the body’s natural alignment. This is why it is imperative that the
body be properly supported, starting at the feet. Any instability from the feet can result in
any number of problems along the legs, knees, hips, or even spine of the body.
Throughout normal gait, the body’s joints are inter-connected; one joint’s
movements effect the next joint’s movements (Danclik). With a normal force loading
stance the feet evert slightly to an average of 30 degrees, and a plumb line is lowered
from the sacral promontory whose line is between the navicular bones of the feet
(Danclik). As the foot pronates the medial longitudinal arch is jeopardized and may result
in a collapsing of this arch (Danclik). Once the medial longitudinal arch is deteriorated
the foot’s vaulted arch stability is lost and clinical symptoms will rise up along the leg,
manifesting as things like – shin splints, gastructnemious cramps, plantar fascitis, heel
spurs, or stress fractures (Danclik).
This upward traveling manifestation does not stop there; depending on how much
pronation has occurred the effects may travel further up. The femor may be affected, and
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thus bringing the greater trocantor forward and out. The muscle at the greater trocantor,
the piriformus, will result in a stretch that affects it’s attachment points in the sacrum.
The inflicted side may be affected by subluxated anterior, inferior position because of the
stretch put on the piriformus (Danclik). Due to this subluxation, the glutious maximus
moves to compensate and thus a further chain of afflictions will begin.
Flat feet do not just manifest from an over load of stress to the foot and it’s
vaulted arch, but can be due to a lack of development. This lack of development occurs
when the large medial fat pad does not decrease into the medial longitudinal arch
(Danclik). This developed flat foot can be classified as either ridged or flexible. A
flexible foot can be determined by observing the foot while in a non weight bearing
seated position. If the foot holds an arch while in a non weight bearing position or while
on the toes then it is considered to be flexible and treatable with arch supports (Danclik).
But if the foot remains observably flat then the foot is considered ridged and the patient
must seek a specialist’s help. These conditions are, however, rare with only 28 to 35
percent of all school children diagnosed with such a problem and 90 percent of those will
still develop an arch before they turn ten years old (Danclik).
No matter how rare this problem is it is still an issue that afflicts many Americans
and must be treated to help prevent the chain of problems that may result from the
structure abnormality. The structured support that orthotics offer will help discourage
pronation and encourage normal function of the foot and ankle (Danclik). By maintaining
normal weight, increasing muscle strength and flexibility, along with the addition of
custom orthotics, the patient should be able to correct the problem before it becomes
irreversible. The most important part is gaining custom orthotics.
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Orthotics is not just a funny word, it is a very useful device that helps
stabilize the foot and offers a good base of support for the body. There are three basic
types of ortontics; those that are functional, protective, and a mix of both function and
protection. Each different type serves the wearer in a different way.
Functional orthotics are made out of a rigid material, typically plastic or carbon
fiber. These types of orthotics are normally used for walking or dress shoes and control
motion of the foot in two major foot joints. While protective orthotics are typically a
softer material so that they can absorb the loads put on the foot. By absorbing the loads
placed on the foot it can increase stabilization and take the pressure off uncomfortable or
sore spots of the feet. This type of orthotic rests against the sole of the foot and extends
from the heel past the ball of the foot.
The third option of orthotics lies someplace in-between with a soft surface
reinforced with a ridged support. This type of orthotic offers both functional support and
protection. It is this third type that is often prescribed to athletic patients and can vary
between sports; they are often used to mitigate pain while the athlete practices or
competes. In the case of all three, the orthotics must be customized to support the
wearer’s particular deformity.
The customization of orthotics will vary between orthotic companies. However,
they will all make some sort of cast of the weight bearing patient’s feet. The casting is
typically done in the podiatrist’s office and is sent out to the orthotic maker. The cast is
then utilized when the company produces the patient’s chosen type of orthotic; to craft
the orthotic the casting creates a three dimensional image of the foot. From this image the
company then makes an orthotic that will help support the weakened areas and assist the
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foot in each step. This individualized orthotic is then sent back to the doctor’s office.
Some insurance companies will cover the expense of these custom shoe inserts while
others do not yet understand the research that supports the use of orthotics.
There has been extensive data collected on the effectiveness of these prescribed
orthotics. One such study was conducted in 1988 in which 20 subjects with flatfeet were
observed for their oxygen consumptions pre and post orthotics (Danclik). The
participants were put on a tredmill and observed walking with out orthotics and then
with. Their medical history was taken also and besides flat feet they were not
symptomatic. The results indicated that when the participants used orthotics their gait
efficacy rose and oxygen consumption decreased (Danclik). This study is only one in
several that supports the use of orthotics in gait stability.
Another study observed the use of orthotics in 40 participants who all had
bilateral hyperpronation. Bilateral hyperpronation can cause any number of issues with
the lower extremities and tissues. One known issue it causes is a change in the quadriceps
femoris angle (Q- angle). The Q-angle is known as the angle at which the anterior
superior iliac spine (ASIS) connects with the center of the patella and where the line of
the tibial tubarsity connects with the patella center. This angle has been associated with
patella abnormalities, including patellar displacement.
The study selected 40 male participants from the Logan College of Chiropractic
and the Montgomery Health Center (Kuhn). To determine if the participants were, infact, bilateral pronators their gait was observed for any external rotation or toe-outing
during the planting phase of gate. Then the researchers examined the participants’ shoes
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for lateral wear. Lastly the participants’ Achilles tendons and the length of their medial
arches were noted.
Casting of the participants feet were made by the Foot Levelers casting kit and
full length flexible orthotics were made. The participants’ Q-angles were measured while
they were in a standard knee extended position and in their normal footwear. The angle
itself was measured using a 12 inch goniometer with a 24 inch arm. Only one person
conducted measurements and that examiner did not know if the participant was wearing
orthotics or not. The average measured Q-angle on the left was 12.1 degrees with a
standard deviation of 2.6 degrees, while it was 11.8 degrees on the right with a standard
deviation of 2.2 degrees (Kuhn).
While this study does not have as large of subject pool as desired it does have
significant results. With out orthotics the participants had a mean 2.3 degree asymmetry;
after orthotics were inserted the population had a mean 1.4 degree asymmetry (Kuhn).
This indicates a 0.9 degree decrease in the Q-angle’s asymmetry(Kuhn). It was also
indicated that when the initial difference was larger the decrease in Q-angle asymmetry
was also larger. This is a great study when examining the usefulness of orthotics.
Many other studies have been done to indicate the need for orthotic support. Most
studies show minimal benefit at the very least, with most indicating much more
significant findings. A much larger study conducted by Karl B. Landorf of La Trobe
University was conducted and found little to support the use of custom orthotics over
sham orthotics in the treatment of planter fasciatis.
Planter fasciatis is a inflammation of the planter fascia. It is believed that the
radiating pain from the heel to the toes is from repeated partial tearing of the enthesis and
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chronic inflammation that occurs (Stuber). This inflammation and painful clinical
symptom is often treated by use of orthotics because it is believed that this injury is due
to improper foot biomechanics. The Landorf study tests the treatement of planter
fasciatis with orthotics by introducing the subjects to either custom orthotics, over the
counter orthotics, or shame (fake) orthotics.
The three types of orthotics the Landorf study used were randomly assigned to the
135 participants. These participants, mostly female, were given one of the three orthotics
and then observed at three and twelve months. When observed at the three month period
the participants who wore prefabricated (over the counter) or custom orthotics showed
improvement only in their function compared to those who wore fake orthotics. Pain
levels in both groups were equal at both the three and twelve month examination
(Napoli). However, function at the twelve month examination was also equal in both
subject groups (Napoli). This study, while important, does not attest or disprove the
usefulness of orthotics in increasing support to an abnormally functioning foot.
Feet that have arch abnormalities are obviously in need of additional assistance in
supporting the forces that the foot needs to absorb in a day. Many people with such arch
instabilities have radiating problems that affect not only their lower legs but all the way
up to their knees, hips, and spine. Understanding the mechanics of the foot, the arches
and chain of joints, the orthotics and studies, will help the chronic low back pain sufferer
realize the actual cause of that stiffness is in the feet.
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