PLANTAR FASCIITIS
The human foot has evolved from a flexible grasping organ to a relatively rigid
weight bearing supportive system. Some claim that the evolution of the foot has
been less than successful, or at least incomplete. For example, still present
are the grasping muscles, which are of reduced importance.
The foot is composed of 33 joints and 26 bones, grouped as the seven tarsal
bones (talus, calcaneus, navicular, cuboid, medial cuneiform, intermediate
cuneiform, and lateral cuneiform); five metatarsal bones (arranged medial to
lateral); and fourteen phalanges (three for each toe, except for the great toe,
which only has two).
The bones of the foot articulate such that they form three
structural arches that, along with an extremely complex system of ligaments, and
to a lesser degree, of muscles, providing five layers of support. These arches,
two longitudinal (medial and lateral) and one transverse, contributing to the
strength, stability, mobility, and resilience of the foot. During weight bearing
and other types of loading, the arches serve as shock absorbers, dissipating
energy before it is transferred across the ankle joint and the shank.
The plantar fascia is found on the bottom of the foot.
Running longitudinally, it is divided into central, lateral, and medial
portions. It attaches posteriorly (back of) on the calcaneus and the anterior
(front of) at the base of the first row of phalanges (toes).
Plantar Fasciitis is a common foot disorder in
runners--although the cause remains unknown, anatomical abnormalities and
overuse are suspected. The plantar fascia is presented as a truss, which is a
rigid structure composed of elements fastened as to resist changes in its shape
by preventing motion between its elements. Its purpose is to support a larger
load or span a greater distance than the individual elements could by
themselves. The plantar fascia serves as a mechanism by which the tarsal joints
may be passively stabilized. As an individual performs heel raises or any
activity requiring toe extension, the fascia becomes stretched and tightened
because of the changes in orientation of its attachment at the toe area. This
change then shortens at the base of the truss, from the heel to the ball of the
foot. The result is tarsal and metatarsal stabilization and an increase of the
height of the longitudinal arch.
Typically, a normal foot has a medium height longitudinal
arch, which is an imprint of the foot not unlike a fingerprint, and a vertically
oriented hindfoot, which is the angle that the achilles tendon makes from the
vertical. A flat foot, or pes plantus, has a low arch or no arch and is often
pronated. Pes cavus, or a highly arched foot, is supported mostly at the fore
and hind foot.
The manner in which loads are distributed under the foot
has been a focus of investigation for decades. In the normal weight-bearing
stance, all of the metatarsal heads are in contact with the ground and together
bear 50% of the load, the heel being responsible for the other 50%. The
metatarsal of the great toe is responsible for twice the load of the other
metatarsals.
Now that we have addressed the functions and anatomical
make up of the foot treatment for plantar fasciitis is done through specific
exercises to strengthen the arch as well as the integrity of the ankle.
Orthotics are given to people with flat feet to aid in the support of the arch
and various Physical Therapy modalities such as ultrasound are administered to
promote healthy tissue growth and healing after activity and exercises.
If you have any concerns in reference to this disorder
please feel free to stop in APTA and ask any of our qualified staff members
questions to help you better understand or prevent this from progressing.
Knowledge is prevention