LOWER LIMB 2: Bones & Muscles

Question 1

Anterior features of lower leg

Answer 1

PROXIMAL TIBIOFIBULAR JOINT = PLANE SYNOVIAAL

TIBIAL TUBEROSITY

INTEROSSEUS MEMBRANE

FIBULAR NOTCH

LATRAL MALLEOLUS of fibula

Question 2

Compare the two tibiofibular joints

Answer 2

PROXIMAL = PLANE SYNOVIAL

DISTAL = SYNDESMOSIS

Question 3

ANTERIOR COMPARTMENT MUSCLES OF THE LOWER LEG: components, nerves, actions

Answer 3

DORSIFLEXION
INVERSION
+toe extension

(deep fibular n. =. L4-S1) - covering shins of the nun

1. TIBIALIS ANTERIOR
2. EXTENSOR HALLUCIS LONGUS (big toe)
3. EXTENSOR DIGITORUM LONGUS (lateral 4 toes)
4. FIBULARIS TERTIUS
   * medial to lateral = T H D

Question 4

LATERAL COMPARTMENT MUSCLES OF THE LOWER LG

Answer 4

EVERSION
+ plantarflex (weak)

(superficial fibular n. - L5-S1) - Lateral Clive’s Hit n Run

1. FIBULARIS LONGUS
2. FIBULARIS BREVIS

Question 5

Significant tendons on the foot dorsum

Answer 5

Tendinous sheath of Tibialis Ant.

Tendinous sheath of Ext. Digitorum Longus & Fibularis Tertius

and
Tendinous sheath of Ext. Hallucis Longus (deeper and laterl to tibialis ant. sheath.)

Question 6

What type of joint is the ankle joint?

Answer 6

hinged synovial joint to produce = PLANTAR AND DORSIFLEXION

+hyaline articular cartilage of talus

Question 7

When is the malleolar grip the strongest?

Answer 7

Dorsiflexion, when the talus is gripped tightly

Question 8

What does the talus articulate with

Answer 8

MALLEOLUS of tibia and fibula (superiorly)

CALCANEUS (posteriorly)

NAVICULAR (anterior)

Question 9

Bones of the toe

Answer 9

(most medial) 
medial cuneiform
intermed. cuneiform
lateral cuneiform
CUBOID

then

METATARSALS

Question 10

Which is the weaakest ligament of the ankle?

Answer 10

Anterior talofibular lgmnt = common tear during

SUPINATION-EVERSION injuries

Question 11

Subtalar joint significance

Answer 11

Talus and Calcineus = Subtalar joint

= eversion & inversion

*inversion common sprain

Question 12

Features of the popliteal fossa

Answer 12

upper medial border

• semimembranous - flatter!
• semitend.
• semimembr.

upper lateral border
*biceps femoris

contents

1. POPLITEAL ART. + POPLITEAL VEIN
2. TIBIAL N. (bifurcating from Scitatic)
3. COMMON FIBULAR NERVE. (bifurcating from Scitatic)
   * common fibular most lateral!

Question 13

SUPERFICIAL POSTERIOR GROUP OF MUSCLES (calfLL)

Answer 13

PLANTARFLEX
INVERSION
(TIBIAL N. - S1, S2)
*all insert into the calcaneus tendon to the posterior insertion into the calcaneus bone

1. GASTROCNEMIUS = plantarflex + knee flexor
2. PLANTARIS
   * long tendon
3. SOLEUS

Question 14

DEEP POSTERIOR GROUP OF MUSCLES (calf LL)

Answer 14

Toe flexion and ankle flexion
(TIBIAL N.)

• flexor retinaculum entry to foot
  1. POPLITEUS = lateral rot.
  2. TIBIALIS POSTERIOR
  3. FLEXOR HALLUCIS LONGUS
  4. FLEXOR DIGITORUM LONGUS

Question 15

What is the talonavicular joint?

Answer 15

Synovial Ball and socket = side-to-side pivot

Question 16

What is the talocalcaneal joint

Answer 16

Synovial plane = Lateral sliding movement

Question 17

Significance of the Spring ligament?

Answer 17

The plantar calcaneonavicular ligament

• fibrocart. ligament resists weight
• maintain longitudinal arch and contributes to subtalar joints

-visible MRI underneath ball and socket of the talonavicular joint

Question 18

LAYER 1 of the DEEP FOOT

Answer 18

Flexors

(most medial)
1. ABDUCTOR HALLUCIS

2. FLEXOR DIGITORUM BREVIS (CENTRAL)
3. ABDUCTOR DIGITI MINIMI (lateral)

Question 19

LAYER 2 of the DEEP FOOT

Answer 19

(medial)

1. FLEXOR HALLUCIS LONGUS
2. FLEXOR DIGITORUM LONGUS
3. FLEXOR DIGITORUM ACCESSORIS

+neurovasc. =

• common plantar nerves and arteries
• lateral plantar nrves and arteries

Question 20

LAYER 3 of the DEEP FOOT

Answer 20

adductors and short flexors of toes

1. FLEXOR HALLUCIS BREVIS
2. ADDUCTOR HALLUCIS = ransverse and oblique heads makes a 7 shape
3. FLEXOR DIGITI MINIMI

Question 21

LAYER 4 of theDEEP FOOT

Answer 21

Interossi

Plantar interossei = adduct

Dorsal interossei = abduct

(medial)
1st dorsal & 2nd dorsal

1st Plantar 3rd Dorsal

2nd Plantar 4th Dorsal

3rd plantar & flexor digiti minimi
(lateral)