Lower Extremities - leg, foot and posterior thigh

Question 1

Tibialis anterior m.

DA + action

Answer 1

DA - 1st cuneiform bone and 1st metatarsal bone

Action - dorsiflexion and inversion of the foot

Question 2

Extensor hallucis longus m.

Answer 2

DA - base of the distal phalanx of the great toe

Action - Extends great toe and dorsiflexes the foot

Question 3

Extensor digitorum longus m.

Answer 3

DA - tendons attach to the middle and distal phalanges of the lateral 4 toes

Action - Extends the toes and dorsiflexes the foot

Question 4

Fibularis tertius m.

Answer 4

DA - dorsal surface of the shaft of the 5th metatarsal bone

Action - dorsiflexion and eversion of the foot

Question 5

Proximal attachments for all anterior leg muscle

Answer 5

• proximal tibia
• proximal fibula
• interosseous membrane

Question 6

The anterior leg muscles are innervated by

Answer 6

Deep fibular nerve

Question 7

The lateral leg muscles are innervated by

Answer 7

Superficial fibular nerve

Question 8

Skin in what region of the dorsal foot is supplied the cutaneous branches of the deep fibular nerve

Answer 8

Skin b/w great toe and 2nd toe

Question 9

Fibularis longus

Answer 9

Turns around the lateral side of the cuboid bone and enters the sole of the foot

DA - Plantar surface of medial cuneiform and 1st metatarsal bone

Question 10

Fibularis brevis

Answer 10

DA - tuberosity of the 5th metatarsal bone

Question 11

The muscles of the lateral leg compartment have what action?

Answer 11

Eversion and plantar flexion of foot

Question 12

What happens if the common fibular nerve is damaged?

Answer 12

• eversion of foot
• dorsiflexion of foot
• extension of toes
• loss of sensation to dorsum of foot and toes

Question 13

Muscles in the posterior compartment of the thigh

Action

Answer 13

1. Biceps femoris
2. Semitendinosus
3. Semimembranosus

ACTION
-extend the thigh and flex the leg

Question 14

Biceps femoris

PA, DA, innervation

Answer 14

Long head

PA - ischial tuberosity
DA - head of the fibula
innv - tibial division of sciatic nerve

Short head
PA - lateral lip of the linea aspera of the femur
innv - common fibular division of sciatic nerve

Question 15

Semitendinosus muscle

Answer 15

long cord-link tendon at distal end

PA - ischial tuberosity
DA - medial surface of superior part of tibia
innv - tibial division of sciatic nerve

Question 16

Semimembranosus

Answer 16

broad, membrane like tendon at its proximal end

PA - ischial tuberosity
DA - posterior part of medial condyle of tibia
innv - tibial division of sciatic nerve

Question 17

Hamstring part of the adductor magnus muscle

• arises from
• innervation

Answer 17

• Arises from ischial tuberosity deep to proximal attachment of posterior thigh muscles
• hamstring part innv by tibial division of sciatic nerve
• adductor magnus forms the deep boundary of the posterior compartment of thigh

Question 18

Borders of the popliteal fossa

Answer 18

1. Superolateral - biceps femoris

Superomedial - semitendinosus and semimembranosus

Inferolateral and inferomedial - 2 heads of the gastrocnemius muscle

Posterior - skin and deep (popliteal) fascia

Anterior - popliteal surface of the femur, posterior surface of the capsule of the knee joint, and the popliteus muscle

Question 19

Describe the course of the common fibular nerve starting from it’s origni

Answer 19

• Parallels the tendon the biceps femoris tendon

- passes superficial to the lateral head of the gastrocnemius

Question 20

Which vessels are involved in the genicular anastomosis?

Which branches of the popliteal artery participate in the anastomosis?

Answer 20

1. Femoral artery
2. lateral circumflex femoral a.
3. Anterior tibial a.

Superior lateral and superior medial genicular arteries

Question 21

Pes anserinus

Answer 21

Convergence of the sartorius, gracilis and semitendinosus tendons on the proximal end of the tibia

Question 22

Posterior leg compartment

• superficial and deep groups:
• separated by
• action
• innervation

Answer 22

SUPERFICIAL

• gastrocnemius
• soleus
• plantaris

Action -> plantar flexion of the foot

DEEP

• popliteus
• tibialis posterior
• flexor digitorum longus
• flexor hallucis longus

Action -> inversion and plantar flexion of foot + flexion of toes

SEPARATED BY - transverse intermuscular septum

INNERVATION - tibial nerve

Question 23

Gastrocnemius

Answer 23

PA - femoral condyles for each head
DA - calcaneal tuberosity by way of the calcaneal tendon

Plantar flexes foot

Question 24

Soleus

Answer 24

PA - soleal line of tibia
DA - Calcaneal tendon

Plantar flexes foot

Question 25

Plantaris

Answer 25

PA - lateral supracondylar line of the femur -tendon courses b/w gastroc and soleus in proximal part of leg DA - joins the calcaneal tendon and attaches to the calcaneus Plantar flexor of foot and weak flexor of the knee

Question 26

Popliteus muscle

Answer 26

PA - lateral condyle of the femur DA - posterior surface of the proximal tibia Action - rotates the femur on the tibia to unlock the extended knee - Weak flexor of the leg

Question 27

Tibialis posterior

Answer 27

PA - tibia, fibula and interosseous membrane DA - plantar surface several tarsal bones Action - inverter and plantar flexor of foot

Question 28

Flexor hallucis longus

Answer 28

PA - inferior 2/3 of fibula and interosseous membrane DA - base of distal phalanx of great toe Action - flexes great toe and plantar flexes foot

Question 29

Tom, Dick ANd Harry

Answer 29

Anterior to posterior (posterior to medial malleolus) ``` T - tibialis posterior D - flexor digitorum longus A - posterior tibial artery N - tibial nerve H - flexor hallucis longus ```

Question 30

Fibular artery - comes off of - course b/w - provides blood to

Answer 30

- posterior tibial a. - courses distally b/w tibialis posterior and flexor hallucis longus muscles - supplies blood to: 1. muscles of lateral compartment of leg 2. lateral side of posterior compartment of leg

Question 31

The muscles in posterior leg compartment are innervated by

Answer 31

Tibial nerve

Question 32

Flexor digitorum brevis

Answer 32

Proximal: Calcaneal tuberosity Plantar aponeurosis Distal: Middle phalanges of toes 2-5 Nerve/Artery: Medial plantar nerve/artery Action: Flexion of toes 2-5

Question 33

ABductor hallucis

Answer 33

Proximal: Calcaneal tuberosity (medial side) Plantar aponeurosis Distal: Medial base of the proximal phalanx of the great toe Nerve/Artery: Medial plantar nerve/artery Action: Abduction of the great toe

Question 34

ABductor digiti minimi

Answer 34

Proximal: Calcaneal tuberosity (lateral side) Plantar aponeurosis Distal: Base of the proximal phalynx of 5th toe Nerve/Artery: Lateral plantar nerve/artery Action: Abduction of 5th toe

Question 35

Quadratus plantae

Answer 35

(deep to flexor digitorum brevis muscle) Proximal: Calcaneus Distal: Tendon of the flexor digitorum longus muscle Nerve: Lateral plantar nerve Action: Flexion of toes 2-5

Question 36

Lumbrical

Answer 36

Proximal: Tendon of the flexor digitorum longus muscle Distal: Extensor expansions of toes 2-5 Nerve/Artery: Medial and lateral plantar nerves/arteries Action: Flexion of proximal phalanges of toes 2-5 Extension of middle and distal phalanges of toes 2-5

Question 37

Flexor hallucis brevis

Answer 37

``` (medial and lateral head) Proximal: First metatarsal bone Cuboid bone Third cuneiform bone Distal: Both sides of the base of the proximal phalanx of the great toe ``` Nerve: Medial plantar nerve Action: Flexion of the great toe

Question 38

Adductor hallucis

Answer 38

Proximal: Don’t worry about this Distal: Lateral base of the proximal phalanx of the great toe Nerve/artery: Lateral plantar nerve/artery Action: Adduction of great toe

Question 39

Flexor digiti minimi

Answer 39

Proximal: Base of the 5th metatarsal Distal: Base of the proximal phalanx of the 5th toe Nerve/artery: Lateral plantar nerve/artery Action: Flexion of the 5th toe

Question 40

Interosseous muscles

Answer 40

(plantar on left; dorsal on right) Attachments: Between the metatarsals Nerve: Lateral plantar nerve Action: 4 Dorsal are ABductors (DAB) 3 Plantar are ADductors (PAD) 2nd toe is the axis

Question 41

Tibial nerve divides into?

Answer 41

Medial and lateral plantar nerves -> common and proper plantar digital nerves