week 7

Question 1

leg and foot – Retinacula

Answer 1

act to hold the tendons in place and to prevent bow-stringing

Question 2

Superior extensor retinaculum

Answer 2

Binds the tendons of TA, EHL, EDL, PT Runs horizontally above ankle

Question 3

Inferior extensor retinaculum

Answer 3

Binds down the TA, EHL, EDL, PT
Y shaped band anterior to the talocrural ligaments

Question 4

Superior and inferior peroneal retinacula

Answer 4

bind down the PL and PB behind the lateral malleolus

Question 5

Flexor retinaculum

Answer 5

• Converts the bony grooves into canals for the tendons of TP, FDL, FHL as they pass behind the medial malleolus
• Bridges over the posterior tibial vessels and nerves

Question 6

leg and foot – synovial sheaths

Answer 6

• Double layer of synovial membrane surrounding each tendon as it passes under the retinacula
• Facilitate sliding of the tendons

Question 7

Muscles of the foot

Answer 7

Intrinsic foot muscles: origin and insertion both within the foot as opposed to extrinsic muscles – origin in leg or thigh, insertion in
foot
Plantar layers described in FOUR layers Superficial to deep

Question 8

what are Dorsal muscles of the foot

Answer 8

• Extensor digitorum brevis
• Extensor hallucis brevis

Question 9

what are the Plantar muscles of the foot – Aponeurosis/Plantar Fascia

Answer 9

• Most superficial structure of plantar surface
• Triangular in shape: apex at the calcaneus, base at the heads of the metatarsals

Question 10

what are the Plantar muscles of the foot – Aponeurosis/Plantar Fascia FUNCTIONS

Answer 10

• binds the skin of the foot
• provides an attachment site for foot muscles
• helps to maintain arches of the foot (more soon)

Question 11

Plantar muscles of the foot – layer 1

Answer 11

One flexor and two abductors
* Flexor digitorum brevis * Abductor hallucis
* Abductor digit minimi

Question 12

Plantar muscles of the foot – layer 2

Answer 12

Two tendons and two muscles:
* Flexor digitorum longus
* Flexor hallucis longus
* Flexor accessorius or Quadratus plantae
* Lumbricals

Question 13

Plantar muscles of the foot – layer 3

Answer 13

One adductor and two flexors
* Adductor hallucis
* Flexor digiti minimi
(brevis)
* Flexor hallucis brevis

Question 14

Plantar muscles of the foot – layer 4

Answer 14

Two tendons and two muscles:
* Peroneus longus
* Tibialis posterior
* Plantar interossei
* Dorsal interossei

Question 15

leg and foot – Dorsal digital expansion

Answer 15

Expansion of the extensor tendons as they approach the digits (toes)

Question 16

leg and foot – Dorsal digital expansion functions

Answer 16

• Allows all the joints of the toe to be extended simultaneously
• Provides attachment for some of the intrinsic muscles

Question 17

Foot Functions

Answer 17

• Weight bearing (balance)
• Propulsion
• Shock absorption

Question 18

when is the foot rigid

Answer 18

• Step-off
• Plantarflex ankle & extend MTP
  joints
• Tightens plantar aponeurosis (Windlass mechanism/effect)
• Raises medial longitudinal arch
• Head of talus moves superiorly
  and subtalar joint supinates
• Mid-tarsal joint is locked

Question 19

when is the foot flexible

Answer 19

• Heel strike - vice versa
• Subtalar joint pronates
• Mid-tarsal joint unlocks

Question 20

Foot longitude Arches

Answer 20

• Two Longitudinal – run from calcaneus to metatarsal heads
• Medial arch
• Lateral arch
• Transverse – runs in coronal plane
• Formed and supported by?
  Fit of the bones
  Joint integrity
  Ligament tightness
  Muscle tension

Question 21

what makes up Medial Longitudinal Arches of the Foot

Answer 21

• Calcaneus
• Talus
• Navicular
• Cuneiforms (all 3)
• Metatarsals I, II, III
• Talus is highest point (keystone)

Question 22

what are the Lateral Longitudinal Arches of the Foot

Answer 22

• Calcaneus
• Talus
• Cuboid
• Metatarsals IV, V
• Cuboid is highest point (keystone)

Question 23

Transverse Arch

Answer 23

– At proximal end formed by
* Metatarsal bases
* Cuboid
* All 3 cuneiform bones at
proximal end
– At distal end formed by
* Head of the metatarsals

Question 24

Functions of Foot Arches

Answer 24

• Absorb weight forces/shock
• Efficient weight bearing – weight bearing areas of foot (hindfoot & forefoot)
• Add to foot’s ability to adapt to changes in ground surface contour
• Efficient propulsion - elastic recoil of arch when weight lifted off (arches flatten slightly when weight-bearing)

Question 25

Static Support for Foot Arches

Answer 25

-- Shape of the bones -- Ligaments * Plantar aponeurosis – both arches * Long plantar ligament – lateral arch * Short plantar ligament (plantar calcaneocuboid ligament) – lateral arch * Spring ligament (plantar calcaneonavicular ligament) – medial arch * All other interosseous ligaments within the medial arch – medial arch

Question 26

Ligamentous Support

Answer 26

* Plantar aponeurosis very important * Thick, triangular shaped * Longitudinal fibres except anteriorly * Near metatarsal head it splits into superficial and deep layers * Toe extension increases the tension in the aponeurosis (due to attachments) * This raises the longitudinal arches

Question 27

Muscular (Dynamic) Support

Answer 27

* provide dynamic support to the arch – walking, running * Two main ways muscle can support the arches which increase concavity * Bowstring or tie beam – pull the ends of the arch together * Sling – lift the summit upwards

Question 28

Eversion

Answer 28

Eversion (combination movement) is Dorsiflexion, Abduction, Pronation

Question 29

inversion

Answer 29

Inversion (combination movement) is Plantarflexion, Adduction, Supination * iPADs – inversion Plantarflexion, ADduction, supination

Question 30

Dorsal Digital Expansion

Answer 30

* Allows all the joints of the toe to be extended simultaneously * Important in digital sweep

Question 31

what is digital sweep

Answer 31

* Longest possible sweep (pathway) of the tips of the digits * Flexion occurs at the MTP first * While the IP joints are maintained in extension * Flexion of the IP joints comes late

Question 32

what happens to allow digital sweep

Answer 32

* Intrinsic muscles act to extend IP joints – to avoid ‘scrunching’ up toes * Lumbricals and interossei

Question 33

how does digital sweep occur

Answer 33

* Interplay between extrinsic & intrinsic foot muscles * Intrinsic muscles modulate the extrinsic muscles

Question 34

what do lumbricals attach to and what are their actions

Answer 34

* Attaches to the dorsal digital expansion * Action of lumbrical * Flex MTP joints & extend IP joints * Prevents toes clawing