Download MBBS (Bachelor of Medicine and Bachelor of Surgery) Latest Arches of the Foot Lecture PPT
ARCHES OF THE FOOT
SKELETON OF THE FOOT
? The skeleton of the foot from behind forward
consists of the following bones:
? Tarsals
? Metatarsals
? Phalanges
? TARSAL BONES
? These are short bones & arranged in three rows:
(a)Proximal row Talus and calcaneus.
(b) Middle row Navicular.
(c) Distal row Three cuneiforms (medial,
intermediate, and lateral) and cuboid.
? METATARSAL BONES
? These are five miniature long bones.
? The five metatarsal bones together constitute the
metatarsus.
? They are numbered from medial to lateral sides as
first, second, third, fourth, and fifth.
? PHALANGEAL BONES
? The phalangeal bones are miniature long bones.
? They are 14 in number in each foot--two for the
great toe and three for each of the other four toes.
? The foot performs two major functions
1. It acts as a pliable platform to support the body
weight during standing position.
? For this function foot is designed in the form of
elastic arches.
? These arches are segmented so that they can
sustain the stress of weight and thrusts at the
optimum level.
2. It acts as a lever to propel the body forward during
walking, running, and jumping.
? For this function, the foot is so constructed that it is
transformable in a lever.
? The segmented arched lever converts the foot into
a spring, which is ideally suited for its functions.
? The foot and its bones are
divided into three
anatomical and functional
segments:
1.Hindfoot consists of talus
and calcaneus.
2.Midfoot consists of
navicular, cuboid,&
cuneiforms.
3.Forefoot consists of
metatarsals and
phalanges.
? The skeleton of the foot is arched both
longitudinally and transversely, with the concavity
directed towards the plantar surface.
? The presence of arches makes the sole concave
both anteroposteriorly and transversely
? During the standing position, the weight of the
body is distributed among three points:
(a) Posteroinferior tuberosity of the calcaneum (heel)
(b) Head of first metatarsal, and
(c) Head of fifth metatarsal
Factors Maintaining the Arches of the
Foot
? The devices used
to support a stone
bridge are:
1. Shape of stones.
2. Intersegmental
ties (staples).
3. Slings.
4. Tie beams
TYPES OF ARCHES
LONGITUDINAL ARCHES
? Each longitudinal arch has: (a) two pillars, (b) a
summit, and (c) joints.
? MEDIAL LONGITUDINAL ARCH
? Formed by the calcaneum, talus, navicular, three
cuneiforms, and medial three metatarsals
? Pillars
1. Posterior pillar medial half of calcaneum.
2. Anterior pillar heads of the medial three
metatarsals.
? Summit
? The talus lies at the summit of this arch. Therefore,
the talus is the keystone of this arch.
? Joints
? The main joints of the medial longitudinal arch are
talocalcaneonavicular and subtalar joints.
? LATERAL LONGITUDINAL ARCH
? Formed by the calcaneum cuboid and lateral two
metatarsals.
? It is characteristically low and almost touches the
ground.
? It is involved in receiving and supporting the body
weight during walking and running.
? Pillars
? Posterior pillarlateral tubercle of the calcaneum
? Anterior pillarheads of the lateral 2 metatarsals.
? Summit
? Lies at the level of articular facets on the superior
surface of the calcaneum.
? Joints
? The main joint of the arch is calcaneocuboid joint.
FACTORS MAINTAINING THE LONGITUDINAL ARCHES
? Factors Maintaining the Medial Longitudinal Arch
? Bones
? The sustentaculum tali partly support the head of talus.
? Ligaments
(a) Plantar calcaneonavicular ligament (spring ligament)
which provides dynamic support to the head of talus
(b) Interosseous ligaments connecting the adjacent bones
(c) Interosseous talocalcanean ligament, connecting these
bones.
? These ligaments act as intersegmental ties.
? Muscles, tendons, and aponeurosis
1. Acting as slings (suspending arch from above):
? The tendon of tibialis posterior lying below the
spring ligament provides supports to the head of
talus and suspends the arch from above.
? The flexor hallucis longus muscle, has three
functions to support the medial longitudinal arch.
(a) It stretches the arch like the string of a bow.
(b) It supports the calcaneus by passing underneath
the sustentaculum tali.
(c) It supports the talus by passing along its posterior
groove
? The tendon of tibialis anterior also exerts a sling
action.
? 2. Acting as tie beams (structures which prevent
separation of the pillars):
? The medial part of the plantar aponeurosis and
abductor hallucis assisted by the flexor hallucis
brevis act as tie beam to maintain the height of
the medial longitudinal arch.
? Factors Maintaining the Lateral Longitudinal Arch
? Bones
? The proper shaping of the distal end of calcaneus and
proximal end of cuboid. The cuboid is the keystone of
longitudinal arch.
? Ligaments
1. Short plantar ligament: broad and thick.
It lies deep to the long plantar ligament and supports
the calcaneocuboid joint from below.
2. Long plantar ligament: long and supports the joints
between the calcaneum, cuboid, and relate metatarsals
? These ligaments act as intersegmental ties.
? Muscles, tendons, and aponeurosis
1. Acting as tie beams:
? The lateral part of the plantar aponeurosis and the
intrinsic muscles of the little toe (lateral part of the
flexor digitorum brevis, abductor digiti minimi
brevis, and flexor digiti minimi brevis) function as
tie beams of this arch.
2. Acting as slings: The tendons of peroneus brevis
and peroneus tertius, which are inserted on the
base of the fifth metatarsal, act as weak slings
from above.
? The tendon of peroneus longus supports the
cuboid bone from above through its pulley-like
action
Differ. between the medial and lateral longitudinal arches
Medial longitudinal arch
Lateral longitudinal arch
Formed by more bones and more joints Formed by less bones and less joints
Characteristic feature is resiliency
Characteristic feature is rigidity
Higher and more mobile
Lower and less mobile
Involved in propulsion during
Involved in receiving and supporting the
locomotion
body weight
(initiating the next step during walking)
Summit is formed by the talus
Summit is formed by the calcaneum
Main joint is talocalcaneonavicular joint Main joint is calcaneocuboid
(the most vulnerable part of the arch)
(the most vulnerable part of the arch)
TRANSVERSE ARCHES
? Anterior Transverse Arch
? Formed by the heads of the metatarsals.
? It is a complete arch because during standing
position the heads of first and fifth metatarsals
come into contact to the ground and form the
two ends of the arch.
? Posterior Transverse Arch
? Formed by greater parts of
the tarsus and metatarsus.
? It is an incomplete arch
because only its lateral end
comes into contact with
the ground during standing
position.
? The complete dome is
formed when the two feet
are brought together
Factors Maintaining the Transverse Arches
? Bones
? Tarsal and metatarsal bones maintain the concavity
on the plantar aspect of the foot skeleton.
? Ligaments
? Superficial and deep transverse metatarsal
ligaments at the heads of metatarsals function as
intersegmental ties to maintain the shallow arch at
the heads of metatarsals.
? Muscles and tendons
1. Acting as tie beams:
The tendons of peroneus longus and tibialis
posterior support the transverse arch as tie beam.
2. Acting as slings:
The peroneus tertius and peroneus brevis on the
lateral side and tibialis anterior on the medial side
support the transverse arch as slings.
3. Acting as intersegmental ties:
The dorsal interossei act as intersegmental ties.
FUNCTIONS OF THE ARCHES
1. Distribute the body weight to the weight-bearing
points of the sole
2. Act as shock absorber during jumping by their
spring like action
3. The medial longitudinal arch provides a
propulsive force during locomotion.
4. The lateral longitudinal arch functions as a static
organ of support and weight transmission.
5. The concavity of the arches protects the nerves
and vessels of the sole.
CLINICAL CORRELATION
? Flat foot (pes planus):
? Commonest problem of foot.
? It occurs due to collapse of medial longitudinal arch.
? During long periods of standing the plantar aponeurosis
and spring ligament are overstretched.
? As a result, the support of the head of talus is lost and
is pushed downward between the calcaneus and the
navicular bones. This leads to flattening of the medial
longitudinal arch with lateral deviation of the foot.
? The effects of the flat foot are:
(a) The person usually has clumsy shuffling gait due
to the loss of spring in the foot.
(b) Liable to trauma due to loss of the shock
absorbing function.
(c) The compression of the nerves and vessels of the
sole is due to the loss of concavity of the sole.
? The compression of the communication between
the medial and lateral plantar nerves leads to
neuralgic pain in the forefoot (metatarsalgia).
? High arched foot (pes cavus)
? The exaggeration of the longitudinal arch of the
foot causes pes cavus.
? This usually occurs because of a contracture
(plantar flexion) at the transverse tarsal joint.
When the patient walks with a high arched foot
there is dorsiflexion of the metatarsophalangeal
joints and the plantar flexion of th interphalangeal
joints of the toes.
This post was last modified on 30 November 2021