Health & Wellness Magazine HealthQuest Fall 2020 | Page 12

ANKLE-FOOT ORTHOSIS
AN INTRODUCTION TO THE
ANKLE-FOOT
ORTHOSIS
BY: BRENDAN WALSH, C. PED (C)
Brendan is a graduate of Memorial University of
Newfoundland, where he earned his honors degree in
Kinesiology in 2014. After graduation, he attended the University
of Western Ontario, where he obtained his Diploma in Pedorthics, and
following that, he became a Canadian Certified Pedorthist in 2016.
WE ALL know that person who sounds
like a herd of elephants when they walk
around the house. While this can be made
light of, the overall physical effect on one’s
lower limbs can cause injury. So what
causes this type of walking pattern?
Well, there are many different factors
such as injury, sickness, and poor
biomechanics. One of the most common
factors of foot slap is a condition known
as drop foot. When someone has drop
foot, the hard slap made when the foot
hits the ground can be caused by weak
or damaged dorsiflexor muscles (the
muscles that help raise your foot up off
the ground). When these muscles are
damaged or weak, the ability to raise your
foot up toward your leg is hindered and
sometimes lost altogether. This motion
while moving is very important as you
need to be able to lift your foot toward
your leg when taking a step or else you
will trip over the foot moving forward. As
a result, the body compensates for this loss
of movement by altering the movement
of the knee, leg, or hip in order to lift
the foot off the ground without tripping.
Furthermore, when one muscle is weak,
the alternative muscle becomes more
powerful in response. This increases a
person’s inability to raise their foot off the
ground.
So is there a solution? Yes! There are
a variety of treatment solutions, but
one of the more common options is
an Ankle-Foot Orthosis, or AFO as it is
more commonly known. An AFO is a
device that helps compensate for lack of
dorsiflexion by redirecting force to create
enough spring in the foot to allow it to lift
up toward the leg and improve walking
functionality. There are many varieties of
materials and shapes of AFOs available,
depending on the severity of the drop foot
condition.
So how does it work? It works due to the
biomechanical principle of pressure. The amount
of pressure on one area is determined by the
amount of force divided by the surface area.
The smaller the surface area, the greater the
pressure will be in that localized area. The goal
of the AFO device is to create a larger surface
area in order to decrease pressure and build
enough ground force reaction to cause a springlike
motion. This spring motion helps recreate
the movement required to lift the foot off the
ground as the walking pattern continues forward.
Other conditions that may require an Ankle-
Foot Orthosis include peroneal nerve injury,
instability in the ankle, mild muscle spasticity,
and/or sensory nerve injury.
Like most orthoses, there are both prefabricated
and custom-made device options. Prefabricated
devices are made based on measurements and
then moulded and adjusted during the fitting
appointment. Custom-made devices are created
from a cast taken of the individual’s lower leg
and foot. Typically, the AFO would fit inside the
shoe, but there are options that connect to the
outside of the shoe as well such as the Dictus
Brace. It should be noted that while the orthosis
is the treatment option, it is important to use it in
conjunction with suitable footwear. The type of
footwear used will determine the level of success
of the treatment. Footwear should be suitable to
the individual’s pathologies and lifestyle. If the
AFO is jammed into a narrow shoe, not only will
this decrease the success of the brace but it may
also lead to new foot problems such as callusing,
corns, or pressure sores.
If you or someone you know might need an
AFO, call 754-5944 or visit healthquestnl.ca to
book an appointment. You can also shop for the
right footwear directly on our online store! Let us
help you keep your feet happy and healthy.
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