2.7.1. ANAT LAB - Sole of Foot

Question 1

What is considered the mortise of the lower extremity?

Answer 1

Ankle-Joint

Question 2

What is considered the tenon of the lower extremity?

Answer 2

Leg

Question 3

What fractures are we concerned about?

Answer 3

The tibia and/or the ankle joint, NOT the fibula We also worry about disruption of the interosseous membrane

Question 4

What is a stress fracture?

Answer 4

Constant stress, not enough to break a bone instantly, but causing failure eventually

Question 5

What are the compartments of the leg?

Answer 5

Anterior, lateral and posterior

Question 6

What causes compartment syndrome?

Answer 6

Anything that affects the volume of the compartment (fracture, exercise, missed injection, scar tissue, tight cast, weight) Pain is the initial and most important sign of compartment syndrome

Question 7

What is a shin splint?

Answer 7

Very mild compartment syndrome (usually anterior) that resolves with R.I.C.E.

Question 8

Action of the Talocrural joint

Answer 8

aka Ankle: flexion/extension

Question 9

Action of the Talocalcaneal joint

Answer 9

aka Subtalar: inversion/eversion

Question 10

Action of the Talonavicular joint + Calcaneocuboidal joint

Answer 10

Forefoot motion

Question 11

What does the Sustentaculum Tali do (what lies beneath it)?

Answer 11

Sustains the talus; FHL tendon runs beneath it

Question 12

Which components of the foot support most of the weight?

Answer 12

The calcaneus and the metatarsals

Question 13

What is the spring ligament?

Answer 13

Plantar Calcaneo-Navicular Ligament (medial side of the foot)

Question 14

What is an ankle strain?

Answer 14

Overloading of any of the ankle ligaments

Question 15

What is Pes Planus

Answer 15

Flat-foot: failure of bony construct and ligamentous structures Patients cannot sustain long distance walking

Question 16

What do all the extensor tendons run under to enter the foot?

Answer 16

The superior and inferior extensor retinaculum

Question 17

What is/are the function(s) of the Plantar Aponeurosis?

Answer 17

Provides stability/strength of the arch

Question 18

What muscles are in the first layer of the foot?

Answer 18

Flexor Digitorum Brevis Abductors of Great and Small Toes (AH & ADM)

Question 19

What two tendons and 2 muscles are in the second layer of the foot?

Answer 19

Flexor Digitorum Longus Tendon and the Flexor Hallucis Longus Tendon

Lumbricals

Quadratus Plantae

~Look for lateral & medial plantar Aa & Nn~

Question 20

What is a hallux valgus?

Answer 20

Bunion (deformity of the MP joint) Usually of great toe

Question 21

What muscles are in the third layer of the foot?

Answer 21

Flexor Hallucis Brevis (sesamoids)

Flexor Digiti Minimi Brevis

Adductor Hallucis: Transverse & Oblique Heads

Question 22

What muscles are in the fourth layer of the foot?

Answer 22

Plantar (3) and Dorsal (4) Interossei

Question 23

Gastrocnemius strain complications?

Answer 23

Can result in a hematoma which leads to compartment syndrome

Question 24

Nerves to the sole of the foot?

Answer 24

Saphenous N.

Medial/Lateral Plantar N.

Sural N.

Calcaneal Branches of Tibial & Sural Nn.

Question 25

Where does the Medial Plantar Nerve innervate?

Answer 25

Motor to:

1st Layer: flexor digitorum brevis (FDB) and ABductor Hallucis

2d layer: Lumbrical of 2nd toe

3d layer: Flexor Hallucis Brevis (FHB)

Question 26

Lateral Plantar Nerve

Answer 26

Everything else that the MPN does not innervate

1st Layer: ABductor digiti minimi

2d layer: quadratus plantae, lumbricals of toes 3, 4, & 5

3d layer: Flexor Digiti Minimi Brevis and ADductor Hallucis (transverse and long heads)

4th layer: plantar and dorsal interossei

Answer 27

Plantar aponeurosis

Answer 28

1. Flexor Digitorum Brevis
2. Abductor digiti minimi
3. Abductor hallucis
4. Plantar Aponeurosis (Cut and Reflected)

Answer 29

1. Quadratus plantae (looks somewhat squared = quadratus)
2. Lumbricals
3. Flexor Hallucis longus (First layer - flexor digitorum brevis, reflected anteriorly)
4. Flexor digitorum longus

Answer 30

1. Adductor hallucis - Oblique head
2. Adductor hallucis - transverse head

Answer 31

1. Flexor hallucis brevis
2. Flexor digiti minimi brevis
3. (Abductor hallucis tendon - cut)
4. (Abductor Digiti minimi tendon - cut)

Answer 32

Dorsal interossei (4)

Answer 33

1. medial plantar n.
2. medial plantar a. (GA p 452, 454; N 522)
3. lateral plantar a.
4. lateral plantar n.

***NOTE: the nerves and vessels run between the second and third layers

Question 34

Describe: fibrous septae (singular = septa) and skin ligaments (M p 610)

Answer 34

Fibrous septae are highly developed skin ligaments that divide the plantar region into fat-filled regions, forming a shock absorbing pad (particularly over the heel of the foot) The skin ligaments also anchor the skin to the underlying deep fascia, improving the “grip” of the sole

Question 35

Describe: plantar aponeurosis (M p 610; Fig. 5.67B, p 611)

Answer 35

arises posteriorly from the calcaneous and functions like a superficial ligament distally, the longitudinal bundles of the collagen fibers of the aponeurosis divide into five bands that become continuous with the fibrous digital sheaths that enclose the flexor tendons that pass to the toes at the anterior end of the sole, the aponeurosis is stabilized by the superficial transverse metatarsal ligament

Question 36

Describe: medial longitudinal arch (M Fig. 5.103, p 656) What bone is the “keystone” of this arch? (M p 654) - the talar head is the keystone of the medial longitudinal arch

Answer 36

medial side of foot is higher and more important than the lateral longitudinal arch composed of: calcaneous, talus, navicular, three cuneiforms, and three metatarsals the tendons of the tibialis anterior and posterior stabilize the arch - the talar head is the keystone of the medial longitudinal arch

Question 37

Describe: lateral longitudinal arch lateral side of foot much flatter than the medial part of the arch rests on the ground during standing made up of the calcaneous, cuboid, and lateral two metatarsals

Answer 37

-lateral side of foot -much flatter than the medial part of the arch -rests on the ground during standing -made up of the calcaneous, cuboid, and lateral two metatarsals

Question 38

Describe: transverse arch (M Fig. 5.103C, p 656) – Review how the tendons of the fibularis longus (FL) & tibialis posterior (TP) support this arch like a stirrup (M p 654; Note: Fig 5.68F, p 613 & Fig. 5.101A, p 655 show this very well).

Answer 38

• runs from side to side (hence, transverse) - formed by the cuboid, cuneiforms, and bases of the metatarsals - the medial and lateral parts of the lateral arch serve as pillars for the transverse arch -the tendons of the fibularis longus and tibialis posterior cross under the sole of the foot, like a stirrup, and help to maintain the curvature of the transverse arch

Question 39

Describe: the plantar calcaneonavicular (“spring”) ligament (M p 654 & Fig. 5.101, p 655)

Answer 39

-extends across and fills a wedge shaped gap between the sustentaculum tali and the inferior margin of the posterior articular surface of the navicular -supports the head of the talus and plays an important role in the transfer of weight from the talus and in the maintenance of the longitudinal arch of the foot (remember that the talus is its keystone)

Question 40

Where do most diabetic foot ulcers often begin?

Answer 40

The weight bearing areas of the foot picture

Question 41

Why is the ankle tighter (more stable) in dorsiflexion than in plantar flexion?

Answer 41

the ankle is relatively unstable during plantarflexion because the trochlea is narrower posteriorly and, therefore, lies relatively loosely in the mortise

Question 42

Define the midline (axis) of the foot. This is different from how the midline of the hand is organized. Through which toe does it pass?

Answer 42

The mid-line of the foot is considered to be bisecting the second toe

Question 43

What does the Babinski sign (an abnormal one) indicate (M p 625)? Remember: This “sign” can be normal in infants and children up to 4 yrs of age (excepting infants with brain injury or cerebellar disease).

Answer 43

-flexion is normal -fanning is abnormal (Babinski sign) and indicates brain injury or disease (except in infants) [usually not accurate until 4 years of age]

Question 44

What is: talipes equinovarus (clubfoot)

Answer 44

-refers to a foot that is twisted out of position -all types are congenital -the most common type involves the subtalar joint -the foot is inverted and plantarflexed, and the forefoot is adducted

Question 45

What is hallux valgus?

Answer 45

-foot deformity caused by pressure from footwear and degenerative joint disease -characterized by lateral deviation of the great toe -more common in females and with age -causes a decrease in the medial longitudinal arch

Question 46

What is: hammer toe

Answer 46

-foot deformity in which the proximal phalanx is permanently and marked dorsiflexed -deformity usually results from weakness of the lumbrical or interosseous muscles -a callus will often develop on the top of the toe

Question 47

What is pes planus?

Answer 47

-flatfeet -may be flexible or rigid -result from loose or degenerated intrinsic ligaments (if congenital) -if acquired, usually due to dysfunction of the tibialis posterior -head of the talus becomes displaced inferomedially and becomes prominent

Question 48

Where would you make an incision on the foot (e.g., for an infection) to avoid a painful scar?

Answer 48

When possible, the incision is made on the medial side of the foot, passing superior to the abductor hallucis to allow visualization of critical neurovascular structures