arches of foot structure and function

1. The first foot
On moon

5. Human Foot performs
- supports weight of body
- serves as lever to propel
body in walking & running
Child starts walking without support at 18 months age
Myelination of pyramidal tracts begin
Arches begin to get shape

6. These functions are carried out by
1. Foot skeleton made of series of small bones
- Foot acts as a segmented lever with multiple joints
thus becomes pliable and adapts to uneven surfaces
2. Long Flexors and Intrinsic muscles of foot act on
forepart of foot and assist propulsive action of
gastrocnemius and soleus

7. These functions are carried out by
2. Long Flexors and Intrinsic muscles of foot act on
forepart of foot and assist propulsive action of
gastrocnemius and soleus

8. Arches of foot
1. Longitudinal
2. Transverse
Concavity of both arches directed
to the plantar surface
Functions of arches
1. Proportional distribution
of weight

9. Body weight
120 pounds
Rt. Foot - Talus
60 pounds
Lt. Foot - Talus
60 pounds
Rt. Calcaneus
30 pounds
Heads of
5 Meta tarsals
30 pounds
6 Bearing points
4 metatarsals + 2
sesmaoids under hallux
Each 5 founds
1
2
3
4
5
6

10. Functions of arches
2. Arched foot acts as a segmented lever
Fore part of foot short muscles and long flexors
assist gastrocnemius and soleus
helps in take off of fore part from ground
Lumbricals prevent buckling from contraction of
Flex. Dig. Longus

11. Functions of arches
3. Plantar concavity protects plantar vessels and nerves
from compression
Flat foot – compression leads to Metatarsalgia

12. Functions of arches
4. Arched foot is dynamic and pliable
- When foot is on the ground arch flattens
- Off the ground restores original contour
Acts like a spring board

13. Functions of arches
5. Invertors lift foot on medial side shifts weight to lat.border
Tibialis anterior, Tibialis posterior
Evertors lift foot on lateral side shift weight to med. Border
Peroneus longus, brevis assisted by Per. Tertius
LATERALMEDIAL
Tib.Posterior
Tib.Anterior
Per.Longus
Per.Brevis
Per.Tertius

14. Longitudinal arch
Medial and lateral
Transverse
Medial Longitudinal arch

15. Medial Longitudinal arch
Talus
Tibia
CalcaneusSpring Lig.
Navicular
Med.Cun.
1st
Met.Tar.
Sesam.Bone

16. Medial Longitudinal arch
Summit of arch
Art. Surf.Talus
Post.pillar
Med.Tub.Calcaneus
Ant.pillar
Heads of 1st
to 3rd
Met.Tar
Vulnerable part
Head of Talus
“Key stone”

17. The medial longitudinal arch
This arch is very tall
(which is why the medial side of the foot is missing
from a footprint )
and is extremely resilient due to its large number
of component bones.

18. Lateral Longitudinal arch
Post.pillar
Med.Tub.Calcaneus
Ant.pillar
Heads of 4th
& 5th
Met.tar.
Summit of arch
Sub Talar Joint
Vulnerable part
Calcaneo-cuboid jnt.

19. Lateral Longitudinal arch
5th
Metatarsal
Cuboid
Talus
Calcaneus
Peroneus longus
Suspension

20. The lateral longitudinal arch
The arch is flat and contains relatively less no. of bones
Hence more rigid
Bears the body weight before the medial arch comes into play
Note the foot print

21. The medial and lateral longitudinal arches of the foot

22. Transverse arch
When med. Borders of both feet are approximated a
complete transverse arch is formed
Each foot represents a half dome
Made of prox. By 3 cuneiforms
and cuboid
Distally bases of 5 metatarsals

23. Transverse arch

24. Factors maintaining arches of foot
Med. Long. Arch:
1 Shape of bones
wedge shape with thin edge downwards
Talus “key stone” rests on concave art.surface of
navicular and on sustentaculum tali of calcaneus
2 Intersegmental tiers - like staples
Plantar ligs. Spring Lig. (supported from below by Tib.Post.)
permanent stretch of spr.lig. Produces flat foot.
3. Factors acting as tie beams
Plantar aponeurosis, Abd.Hallucis,
Med.part of Flex.dig.brevis, Tendon of Flex.Hal.Longus,
Med.part of tendon of Flex.dig.longus, Flex.hal.brevis
4. Suspending arch from above
Tendon of Tib.anterior, Sup.fibres of Delt.Lig.
Tend. Of Tib.Post.

25. Factors maintaining arches of foot
Lat. Long. Arch:
1 Calcaneal angle of cuboid
supports ant lower art.surf. of calcaneus
– upward tilt of long axis of calcaneus
2 Intersegmental tiers - like staples
Long and short plantar ligs.
3. Factors acting as tie beams
Plantar aponeurosis, Abd.dig.minimi,
Lat.part of Flex.dig.brevis,
Lat.part of tendon of Flex.dig.longus, Flex.dig.min.brevis
4. Suspending arch from above
Tendon of Per.brevis and tertius exert sling action
Peroneus longus – long course below foot
- sustentacular action

26. Factors maintaining arches of foot
Transverse Arch:
1 Shape of bones
Wedge shaped 3 cuneiforms
Bases of middle 3 metatarsals accentuate arch
2 Intersegmental tiers - like staples
Deep transverse ligs, other intrinsic plantar ligs.
Dorsal interossei,
Oblique and transverse heads of add. hallucis
3. Factors acting as tie beams
Tendons of per. Longus and Tib. Posterior
4. Acting from above
Per. Longus and tertius on lat. Side
Tib.anterior on med. Side
Factors which maintain long. Arches also maintain Trans.arch.

27. Deformities of the foot
1 Pes planus – Flat foot
2 Pes Cavus – High arched foot
Exaggeration of long. Arch
Toes dorsiflexed at metatarso-phalang. Joints
plantarflexed at inter-phalang. Joints - Claw foot
3. Club Foot – Talipes – congenital or acquired
a. Talipes equinus – Toes dorsiflexed and directed to ground
similar to horse
b. Talipes calcaneus – Heel remains on ground toes are
upturned
c. Talipes varus – Foot fixed in inversion and adduction
d. Foot fixed in eversion and abduction

28. Deformities of the foot
Foot print
(Normal)
Flat foott
(Pes planus)
Highly arched foot
(Pes cavus)

29. Deformities of the foot
March Foot
Neck of intermediate metatarsals undergo
decalcification
Minor injury may lead to pathological fracture
Commonly observed in soldiers prolonged walk after
prolonged sedentary rest

30. Deformities of the foot
Hallux vulgus
Great toe adducted towards midline
1st
Metatarsal abducted
wearing of narrow pointed shoes results in undue
prominence of medial part of metatarsal head and
a bunion may develop