L8.1 Foot

Question 1

Tarsal Bones

Answer 1

3 rows of bones:

Calcaneus , Talus
Navicular, Cuboid
Cuneiform x 3

Question 2

Calcaneus

Answer 2

• (↑ in size evolutionarily)
• Talar articulation (3 surfaces)
• Calcaneal sulcus → groove between the surfaces
• Tarsal sinus: LAT, between talus & calcaneus
• Cuboid articular surface
• Calcaneal tuberosity (where Achilles tendon attach)
• 2 tubercles (MED & LAT) → plantar ligament attachments

Question 3

Talus

Answer 3

• Fib + Tib contact
• Head, Neck, Body
• Sulcus tali → forms the tarsal sinus
• Trochlea → enables dorsi/plantar
• Facet for MED & LAT malleolus
• Articular surfaces: Navicular, distal tibia
• Groove for FHL

Question 4

Blood supply of the Talus

Answer 4

• No muscles attachments (which directs blood vessels to bones)
• Fracture talus → prox part necrotic
• Vascular sling under tarsal
  
  • Supplies from distal aspect to prox
  • Fractures leads to necrosis in the proximal region

Question 5

Navicular

Answer 5

tuberosity (on plantar side) for TP

Question 6

Cuboid

Answer 6

LAT to navi, has tuberosity for TP

Question 7

Cuneiform (3)

Answer 7

MED (1st bone), Intermediate (2nd), LAT (3rd)

Question 8

Sesamoid (2)

Answer 8

bone within lig/muscles

Question 9

Injuries of the Foot bones

Answer 9

• Tarsal coalition: no fine movements (dorsi/plantar)
• Potts fracture: Fracture tibia → fracture fib
• 2nd MT fracture (most common): Sits tightly between LAT & MED cuneiform (March fracture)
• 5th MT: Excess Eversion from tendons

Question 10

Intrinsic muscles of teh FOOT on the DORSUM

Answer 10

• Extensor hallucis brevis: Sinus tarsi → Base proximal phalanx of hallux
• Extensor digitorum brevis: Sinus tarsi → Long extensor tendon

Question 11

PLANTAR Foot muscles: Layer 1

Answer 11

• Originate from Calcaneus
• Abductor hallucis brevis → prox phalanx big toe (MP)
• Flexor digitorum brevis → middle phalanges (MP)
  
  • Like FDS in hand → muscles split
• Abductor digiti minimi → prox phalanx 5th digit (LP)

Question 12

PLANTAR foot muscles: Layer 2

Answer 12

• Quadratus plantae: Calcaneus → LAT border of FDL (LP)
  
  • Flexor accessories: straighten pull of FDL
• Lumbricals x4: FDL tendons → EE (1: MP; 2-4: LP)
  
  • Flexes 1st MT joints, Extends IP joints

Question 13

PLANTAR foot muscles: Layer 3

Answer 13

• Flexor hallucis brevis: 1st MT + Cuboid → base of prox big toe (MP)
  
  • Assists FDL
• Adductor hallucis: 2-4 MT → insert with FHB, LAT prox big toe (LP)
  
  • Also have a transverse adductor hallkucis → transverse across toes (all the way to big toe - unlike the hand)
• Flexor digiti minimi: 5th MT → 5th phalanx (LP)

Question 14

PLANTAR foot muscles: Layer 4

Answer 14

Interossei: 4dAB, 3 pAD (LP)

Question 15

Foot muscle injuries

Answer 15

• Hallux valgus: from tight shoes
• Claw toes: Lumbricals compromised
  
  • Other muscles also affected: FDL, FDB, HL (Functional dificiency)
  • Muscles in transverse plane less likely to be affected: FL, FT, FB… (Muscles for In/Ev)
• Jogger’s foot: Plantar fascia compromised, plantar Ns injured