The Sole and Arches of The Foot Flashcards
Briefly describe the deep fascia of the foot. (Parts, orientation of the collagen fibers …)
- The deep fascia of the foot consists of 3 parts: central, medial and lateral.
- The central part is very thick and termed plantar aponeurosis. The medial and lateral parts are thin and termed the medial and lateral plantar fasciae respectively.
- The collagen fibres are arranged longitudinally in the plantar aponeurosis and transversely in the medial and lateral plantar fasciae.
- [Diagram]
Name the three muscles of the first layer of the foot from medial to lateral. State their innervation and functions.
- Abductor hallucis; medial plantar nerve; abduction and flexion of the great toe
- Flexor digitorum brevis; medial plantar nerve; toe flexion at metatarsophalangeal joints of the lateral four digits
- Abductor digiti minimi; lateral plantar nerve; abduct 5th toe and hence support lateral longitudinal arch during walking/running
- [Diagram]
Name the muscles and tendons of the second layer of the foot. State the innervation and function of the muscles.
Muscles:
Quadratus plantae (lateral plantar nerve; flex the toes)
Lumbricals (first lumbrical is innervated by the medial plantar nerve and the other three are innervated by the lateral plantar nerve; flexion and adduction of the toes)
Tendons: (of) flexor hallucis longus and flexor digitorum longus
[Diagram]
Name the muscles of the third layer of the foot. State their innervation and actions.
- Flexor digiti minimi brevis: superficial branch of the lateral plantar nerve, flexion of small toe at metatarsophalangeal joint and supports lateral longitudinal arch
- Adductor hallucis: lateral plantar nerve, adduction and flexion of the great toe and supports the medial longitudinal arch
- Flexor hallucis brevis: medial plantar nerve, flexes great toe at metatarsophalangeal joint and supports medial longitudinal arch
- [Diagram]
Name 2 intrinsic muscles in the deepest layer of foot and state their innervation. (2 marks)
Dorsal and plantar interossei
Innervation: Lateral plantar nerve
[Diagram]
State the pillars, summit and joints of the medial longitudinal arch.
Pillars
a) The medial half of the calcaneum forms the posterior pillar of the medial longitudinal arch.
b) The heads of the medial three metatarsals form the anterior pillar of the medial longitudinal arch.
Summit
superior articular surface of talus (keystone is talus)
Joints
talocalcaneonavicular and subtalar joints
State the pillars, summit and joints of the lateral longitudinal arch.
Pillars
The posterior pillar of the lateral longitudinal arch is formed by the lateral tubercle of the calcaneum and the anterior pillar is formed by the heads of the lateral two metatarsals.
Summit
calcaneus; superior surface (keystone is cuboid)
Joints
Calcaneocuboid joint
Why is the medial longitudinal arch of the foot higher than the lateral longitudinal arch of the foot?
The medial arch is formed by the calcaneus, talus, navicular, three cuneiforms, and the first three metatarsal bones. The shape and arrangement of these bones create a higher arch compared to the lateral side.
Name the factors maintaining the medial longitudinal arch. (Hint: bones, intersegmental ties, sling, tie beams)
[Diagram: supports of a stone bridge]
Bones
✓ The wedge shape of the bones
✓ The talus is the keystone of the arch
Intersegmental ties
✓ Plantar calcaneonavicular ligament (Spring ligament)
✓ Interosseous ligaments
Sling
✓ Tibialis anterior
✓ Tibialis posterior
✓ Flexor hallucis longus
[Diagram]
Tie beams
✓ plantar aponeurosis (medial half)
✓ abductor hallucis
✓ flexor hallucis brevis
Name the factors maintaining the lateral longitudinal arch. (Hint: bones, intersegmental ties, sling, tie beams)
[Diagram: supports of a stone bridge]
Bones
✓ Wedge-shape of the bones
✓ Cuboid is the keystone of the arch
Intersegmental ties
✓ short plantar ligament
✓ long plantar ligament
✓ interosseous ligaments
[Diagram]
Sling
✓ fibularis longus
✓ fibularis brevis
✓ fibularis tertius
[Diagram]
Tie beams
✓ plantar aponeurosis (lateral half)
✓ abductor digiti minimi
✓ flexor digiti minimi brevis
State the functions of the arches of the foot.
- Distribute the body weight to the weight-bearing points of the sole (e.g., heel; balls of the toes, mainly those of first and fifth toes and lateral border of the sole).
- Act as shock absorber during jumping by their spring like action.
- The medial longitudinal arch provides propulsive force during locomotion.
- The lateral longitudinal arch functions as a static organ of support and weight transmission.
- The concavity of the arches protects the nerves and vessels of the sole.
Identify the deformity and state its effects: [Click here].
Identification: pes planus (flat foot) [collapse of the medial longitudinal arch]
Effects:
1. clumsy/shuffling gait due to loss of spring in the foot
2. the foot becomes more liable to trauma due to loss of the shock absorbing function
3. there may be compression of the nerves and vessels of the sole due to loss of its concavity
Identify the deformity: [Click here].
pes cavus (high-arched foot) [exaggeration of the longitudinal arch]
Identify and briefly describe the deformity: [Click here].
talipes equinovarus: the most common deformity of the foot; the foot is adducted, inverted and plantar flexed
Identify and briefly describe the deformity: [Click here].
talipes equinovalgus: the foot is abducted, everted and plantar flexed. The weight of the patient rests on the medial border of the foot and the medial arch is absent.
