Download MBBS Arches of the Foot Lecture PPT

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