2. Foot:
The terminal portion of a limb which bears weight and
allows locomotion.
The Human foot is a strong and complex mechanical
structure containing 26 bones, 33 joints and many
number of muscles, tendons and ligaments.
The foot can be subdivided into hindfoot, midfoot and
forefoot.
3. Foot has two surfaces:
Plantar surface( sole of
foot)
Dorsal surface(upper
surface of the foot)
4. Dorsal surface:-
The tendons of muscles
of the anterior
compartment of the leg are
situated on the dorsal
aspect of the foot.
5. Tibialis Anterior:-
- Dorsiflexes ankle joint
-Inverts the foot
Extensor Digitorum
Longus:-
-Extends the Toes 2-5
-Dorsiflexes Ankle Joint.
7. Extensor Digitorum
Brevis:-
Originates from the
superior surface of the
Anterior Calcaneum.
Inserts via 4 tendons to
toes 1-4
Extends the toes when
the foot is fully
Dorsiflexed.
8.
9. Dorsalis Pedis artery supplies
the foot and is a direct
continuation of the Anterior
Tibial artery.
DPA pulse may be palpated;
Lateral to extensor hallucis
longus tendon or medially to
extensor digitorum longus
tendon) on the dorsal surface of
the foot.
- distal to the dorsal most
prominence of the navicular
bone.
10. THE PLANTAR SURFACE:-
Also known as sole of the foot.
It is covered in a layer of thick
cornified skin that is
nevertheless sensitive.
Under the skin is a layer of
loculated subcutaneous fat.
Under the subcutaneous fat is
the plantar aponeurosis or
plantar Fascia.
11. :-
Thickened band of deep fascia in the sole of the
foot.
Attachment:-
Posteriorly: Medial tubercle of calcaneus.
Anteriorly: Divides into 5 slips which pass to the
5 toes.
On each side: Attached to the metatarsal bones
by medial and lateral intermuscular septa.
Functions:
Protects the underlying nerves and vessels.
Maintain the longitudinal arches of the foot.
12.
13. There are Four layers of
intrinsic muscles that are
present in the foot.
1st Layer:-
Consists of 3 muscles.
1.Abductor Digiti Minimi
2.Flexor Digitorum
Brevis
3.Abductor Hallucis
14. Abductor Digiti Minimi:-
Originates from
-Calcaneal tuberosity
-Plantar Aponeurosis
Inserts onto the lateral
aspect of the base of the
proximal phalanx of the little
toe.
the little toe.
15. Flexor Digitorum Brevis:-
Splits into 4 tendons that enter
the tendon sheaths of toes 2-5
Each tendon splits into two slips
at the base of the proximal
phalanx to allow the tendon of
flexor digitorum longus to pass
through
The slips then reunite and insert
onto the sides of the shaft of the
middle phalanx of toes 2-5.
16. Abductor Hallucis:-
Originates from
-Medial process of the
calcaneum
-Flexor retinaculum
-Plantar aponeurosis
Inserts onto medial side of
base of Proximal phalanx of
Greater Toe.
the Great Toe.
17. 2nd Layer:-
Consists of the Long Flexor
Tendons and Intrinsic muscle
( Lumbricals and Flexor
accessorious)
Consists of
-Flexor Digitorum Longus
tendons
-Flexor Hallucis Longus
tendon
-Lumbricals
-Flexor Accessorius
18. Lumbricals:-
4 small muscles similar to
the Lumbricals in the hand.
Originate from the tendons of
Flexor Digitorum Longus.
onto the medial
aspect of the dorsal digital
expansions of toes 2-5.
Assist in maintaining
extension of IP joints of the
toes.
19. Flexor Accessorius:-
Deeply placed muscle also
known as Quadratus
plantae.
Originates from the
Calcaneum by 2 heads.
Inserts onto the tendon of
Flexor Digitorum Longus.
Assists Flexor Digitorum
Longus in flexing the toes 2-
5.
20. 3rd Layer:-
Consists of 3 muscles.
-Flexor Hallucis Brevis.
-Adductor Hallucis.
-Flexor Digiti Minimi
Brevis.
21. Flexor Hallucis Brevis:-
Originates in 2 parts:
-Medial limb from the medial
and intermediate cuneiforms
and from the tendons of Tibialis
Posterior.
-Lateral limb from the Cuboid
and lateral Cuneiform.
Inserts onto either side of the
base of the Proximal Phalanx
of Big Toe which flexes it.
22. Adductor Hallucis:-
Very deeply placed and is similar to Adductor pollicis
in the Hand.
Originates by 2 heads:-
-Oblique Head-bases of 2,3,4 metatarsals.
-Transverse Head- from plantar metatarsophalangeal
ligamentsof 3,4,5 toes.
Inserts onto:-
-Lateral sesamoid.
-Base of the proximal phalanx.
Adducts the proximal Phalanx of the Big toe.
Stabilizes the metatarsal Heads.
23. Flexor Digiti Minimi
Brevis:-
Originates from medial part
of plantar surface of base of
the 5th metatarsal.
Inserts onto lateral side of
base of proximal phalanx of
little toe.
Flexes Metatarso-
phalangeal joint(MTPJ) of
Little Toe.
25. Dorsal Interossei:
There are 4 Bipennate dorsal
interossei that arise by two heads
from adjacent metatarsals.
Insertion:
1st Dorsal interossei inserts onto the
medial aspect of proximal phalanx of
the second toe.
The other three inserts onto the
lateral aspect of proximal phalanges
of toes 2,3,4 respectively.
Adduct the toes relative to the 2nd
Toe.
26. Plantar Interossei:-
There are 3 Plantar
Interossei.
They are unipennate
muscles.
Originate from medial side
of 3,4,5 metatarsals.
Adducts toes 3,4,5 (towards
the 2nd toe)
Flexes MTP joints
Extend IP joints.
29. Talus Bone:-
Most superior tarsal bone.
-The only bone of foot that articulates with
the fibula and tibia on Medial malleolus of
the tibia and lateral malleolus of the fibula
and forms Talocrural (ankle) joint.
-No muscles are attached to talus. However
many ligaments are attached to the bone,
and confer the stability of talocrural,
subtalar and talocalcaneonavicular joint.
During walking ,Talus transmits about half
of the body weight to the calcaneus.
30. Navicular Bone:-
The anterior tarsal bones.
It is located on the medial
side of the foot, and
articulates proximally with
the talaus , distally with the
three cuneiform bones, and
occasionally laterally with
the cuboid.
31. Cuneiform Bones:-
Wedge shaped.
Three cuneiform bones.
-Medial
-Intermediate
-Lateral.
They are located between the
navicular and the first, second
and third metatarsal bones and
are medial to the cuboid bone.
32. Cuboid bones:-
Cube-shaped
Cuboid articulates distally
with th fourth and fifth
metatarsals and form fourth
and fifth tarsometatarsal
joints.
Articulates proximally with
the calcaneus and form
calcaneocuboid joint.
33. Calcaneus Bone:
Largest and strongest tarsal
bone.
It constitutes with the heel.
Located in the posterior part
of the foot.
Articulation between anterior
surface calcaneus and
posterior surface cuboid
forms the calcaneocuboid
joint.
34. Metatarsus:-
Intermediate region of foot.
5 metatarsal bones..1 to 5 from
medial to lateral
Each metatarsal bone consists o
proximal base, distal head and an
intermediate shaft.
Articulate proximally with the first,
second and third cuneiform bones
and with the cuboid and form the
tarsometatarsal joints.
Distally articulate with the proximal
row of phalanges and form
metatarsophalangeal joints.
35. phalanges:-
Distal component of the foot
and resemble the hand, both in
number and arrangement.
Toes numbered 1-5 , begining
with the great toe.
Each consists of proximal
base, an intermediate shaft
and a distal head.
Joints between phalanges of
the foot are called the
interphalangeal joint.
36. LISFRANC JOINT:
The Lisfranc joint is the point at
which the metatarsal bones
(long bones that lead up to the
toes) and the tarsal bones
(bones in the arch) connect. The
Lisfranc ligament is a tough
band of tissue that joins two of
these bones. This is important
for maintaining proper alignment
and strength of the joint.
37. Arterial supply of Foot:
Via Two arteries.
1.Dorsalis pedis artery( A
continuation of the anterior
tibial artery.)
2. Posterior Tibial artery.
38. Dorsalis Pedis Artery:
-It begins as the anterior tibial artery, enters the foot.
As it crosses the ankle joint it becomes the dorsalis pedis
artery.
-It passes over the dorsal aspect of the tarsal bones, then
moves inferiorly, towards the sole of the foot.
-It then anastamoses with the lateral plantar artery to form
the deep plantar arch.
40. Clinical significance:
Dorsalis pedis artery pulse:
-It can be easily felt between the tendons of extensor
hallucis longus and first tendon of extensor digitorum
longus.
-It is regularly palpated in patients experiencing vaso-
occlusive diseases of the lower limb.
41. The Posterior Tibial Artery:
-The Posterior tibial artery travels
towards the sole and splits inti lataral
and medial plantar arteries.
- The lateral plantar artery connects
together with the end point of the
dorsalis pedis artery( the deep plantar
artery) in order to create the deep
plantar arch.
- circulation of the toes is done by
branches from this particular arch.
42. Posterior tibial artery and plantar arch:
-On the medial side of the ankle and posterior, towards
the medial malleolus, the posterior tibial artey goes into
the foot via the tarsal tunnel.
-At this point, the posterior tibial artery bifurcates into a
small medial plantar artery and a considerably larger
lateral plantar artery.
43. Deep Plantar Arch:
- The lateral plantar artery turns medially in order to
create the deep plantar arch, which traverses the deep
plane of the sole on the metatarsal bases and the
interossei muscles.
- The deep plantar arch connects with the deep plantar
artery of the dorsalis pedis artery, which enters the sole
from the dorsal side of the foot in the middle of the base
of metatarsals 1st and 2nd.
44. Branches of deep plantar arch:
-A digital branch: travels towards the lateral aspect of the
little toe.
- Four plantar metarsal arteries:
give digital branches towards adjacent side of toes 1
to 5 and the medial aspect of the great toe.
- Three perforating arteries: pass between the bases of
metatarsals 2 to 5 to anastomose with vessels on the
dorsal aspect of the foot.
45.
46.
47. ARCHES OF FOOT:-
The foot has three arches:
-Two Longitudinal (medial
and lateral) arches.
-One Transverse arch.
Their shape allows them to
act in the same way of spring,
bearing the weight of the
body and absorbing the shock
produced during locomotion.
48. Medial longitudinal arch:
The medial longitudinal arch is composed by the
Calcaneum, talus, navicular, 3 cuneiforms and
medial 3 metatarsals.
49. Its constitution is as follows:
A. Ends: The anterior end is formed by the heads of first,
second, third metatarsals and posterior end is formed by
medial tubercle of calcaneum.
B. Summit: It is formed by the superior articular surface
of the body of tulus.
50. C. Pillars: The anterior pillar is longer and weak formed
by talus, the navicular bone, the three cunieform and the
first three metatarsals.
-The posterior pillar is short and strong, it is formed
by medial part of the calcaneum.
D. Joint: The main joint of the arch is the
talocalcaneonavicular joint.
51. Lateral Longitudinal
Arch:
The lateral longitudinal arch
composed by the calcaneum,
cuboid and lateral 2
metatarsals.
It is characteristically low
and just about touches the
earth.
It is involved in receiving
and supporting the body
weight during walking and
running.
52. It constitution is as follows:
Ends-The anterior end of the arch is formed by the heads
of the 4th and 5th metatarsal bones.
-The posterior end is formed by the lateral tubercle
of the calcaneum.
Summit: It lies at the level of the articular facets of the
superoir surface of the calcaneum (ie.,at the level of
subtalar joint)
53. Pillars: The anterior is long and weak, it is formed by
the the cuboid bone and by the 4th and 5th metatarsals.
-The posterior pillar is short and strong, it is
formed by the lateral half of the calcaneum.
Joint: The main joint of the arch is the calcaneocuboid
joint.
54. Tranverse Arch:-
Anterior Transverse arch:
-The heads of the
metatarsals create the
anterior transverse arch.
-It is a whole arch because
during standing position the
heads of first and fifth
metatarsal come into
contact to the earth and
create the 2 ends of the
arch.
55. Posterior Transverse arch:
The posterior transverse arch is
composed by greater parts of
the tarsus and metatarsus.
It's an incomplete arch because
only its lateral end enters into
contact with all the earth during
standing position.
It creates only half dome in a
single foot.The entire dome is
composed when both feet are
brought together.
56.
57.
58.
59. Biomechanics of arch support:
The weight of the body would flatten the longitudinal
arches if they were not supported.
Place two pencils upright(perpendicular) on the table on
front of you, and press down gently onto the top.
The force and the resultant force are acting in the same
line and the pen should be stable.
Newton's 3rd law:
If we think of the simple arch structure of a pitched roof,
the weight of the roof supported at two ends. The action
of the load has equal and opposite ground reaction force.
60. Manitenance of the Longitudinal arch:
a) Bony factor: The shape and constitution of the
bones keep the foot in the arching position.
b) Slings or stirrups:
The muscles whose tendons run into the apex of the
arches and tend to increase their height.
The summit of the medial longitudinal arch is pulled
upwards by tendons passing from posterior
compartment of the leg to the sole .
61. The summit of the lateral longitudinal is pulled upwards
by the peroneus longus and peroneus brevis.
The tendons of the tibialis anterior and peroneus longus
together form a sling which keeps the middle of the foot
pulled upwards thus supporting the longitudinal arches.
The tendons of peroneus longus which runs transversly
across the soles, it pulls the medial and lateral margins
of the sole closer together thus maintains the transverse
arches, it also supported by tibialis posterior.
62.
63. Intersegmental Ties:
All arches are supported by the ligaments uniting the
bones concerned, the spring ligament
(calcaneonavicular ligament) for the medial longitudinal
arch.
The long and short plantar ligaments for the lateral
longitudinal arch.
In Transverse arch the metatarsal bones held together
by interoseus muscles.
64. Tie beams:
The longitudinal arches are prevented from flattening by
the plantar aponeurosis and by the muscles of the arches
pulled together.
The plantar aponeurosis has slips to the toes.
Extending(raising) the toes tightens the plantar
aponeurosis and heightens the longitudinal arches.
The plantar aponeurosis links the extremieties of the
arches , and acts as the equivalant of a tie beam in an
architectural arch.
67. :-
-Spread the body weight to the weight bearing points of
the sole (Example, heel; balls of the toes,primarly those
of first and fifth toes and lateral border of the sole).
-Serves as shock absorber during bound by spring like
activity.
-The concavity of the arches protects the nerve and
vessels of the sole.
