Unit 4- Anterior And Lateral Leg Flashcards
Which leg bone is weight bearing?
Tibia
The tibia forms the ____ ____ of the ankle joint
Medial malleolus
Function of fibula
Provides muscular attachment
Forms lateral malleolus of ankle joint
What joins the tibia and fibula, and is the origin of a number of leg muscles?
Provides no significant role in force transmission
Interosseous membrane
The “hinge” joint with the femur. AKA the knee joint
Tibial plateaux
Where the tendon from the thigh muscles and patella attaches, that moves the lower leg forwards at the knee joint- the extensor muscles
Tibial tuberosity
Part of the fibula that forms the bony lump on the outside of the ankle joint
Lateral malleolus
Bottom of the tibia, forms a “hinge” jointwith the talus bone of the foot
Ankle joint
Part of the tibia forms the bony lump on the inside of the ankle joint
Medial malleolous
The leg is divided into what compartments?
Anterior, lateral and posterior
What separates the leg compartments?
Anterior and posterior intermuscular septa and the interosseous membrane
Contents of the anterior compartment
Extensor digitorum longus
Extensor hallucis longus
Anterior tibial artery and vein
Deep fibular (peroneal) nerve
Tibialis anterior
Contents of the lateral compartment
Superficial fibular nerve
fibularis longus
fibularis brevis
Location of the flexor compartment
anterior to the interosseous membrane between the lateral surface of the tibia and the medial surface of the fibula
the flexor compartment is enclosed by what?
the deep fascia of the leg (which is a continuatin of the fascia of the thigh)
Where is the flexor compartment denser?
superiorly
The flexor compartment, AKA:
anterior compartment
why does the anterior compartment have an increased risk for compartment syndrome?
due to the small size of the compartment and its tight fascial borders
The fibular nerves (ARE/ARE NOT) in the same compartment as the fibular vessels
are not
The superior extensor retinaculum transverses from the ____ to the ______ proximal to the ____
Fibula
Tibia
Malleoli
The inferior extensor retinaculum is a Y shaped ____ ____ band extending from ___ ___ ___ to the:
deep fascial
anterior superior calcaneous
tibial malleolus and plantar aponeurosis
What tendons run through the retinaculum
fibularis tertius
extensor digitorum longus
extendor hallicus longus
tibialis anterior tendon
Main function of the anterior compartment muscles
dorsiflexion (has 25% of the power of plantar flexion)
main function of clearing the toes during swing phase of normal gait (concentric) and forefoot touch-down after heel strike (eccentric)
What are dorsiflexors of ankle and extensors of the toes
tibialis anterior
extensor digitorum longus
exterdor hallicus longus
Fibularis tertius
OINA for tibialis anterior
OR: Lateral condyle
IN: Medial cuneiform bone
Base of the 1st metatarsal
AC: Dorsiflexes the foot at the ankle
Inversion of foot
NS: Deep fibular nerve
Blood supply to tibialis anterior
anterior tibial artery
What is the largest muscle of the anterior compartment? It is also the strongest dorsiflexor of the foot
tibialis anterior
Tibialis anterior is antagonized by the _____ ____, except when?
tibialis posterior
when they work synergistically in foot inversion
OINA for extensor digitorum longus
OR: Lateral condyle
Anterior surface of fibula
upper interosseous membrane
INS: Extensor expansion (medial and lateral slips to distal phalanx. Central slip to middle phalanx)
AC: Extends lateral 4 toes
Dorsiflexes foot
NS: Deep fibular nerve
What is the most lateral muscle of the anterior compartment?
extensor digitorum longus
OINA for extensor hallucis longus
OR: Anterior middle portion of fibula
Interosseous membrane
INS: Dital phalanx of digit 1
AC: Extends digit 1
Dorsiflexes foot
NS: Deep fibular nerve
What is the extensor hallucis longus covered by?
EDL and TA
OINA for fibularis tertius
OR: Anterior inferior 1/3 of fibula
Interosseous membrane
INS: Base of 5th metatarsal
AC: Eversion of foot
Dorsiflexes foot
NS: Deep fibular nerve
Fibularis tertius is a separate part of the ____. It is a stronger _____ than ____
EDL
Everter than dorsiflexor
Fibularis teritus plays a role in protecting what ligament?
anterior talofibular ligament
- commonly injured ligament with a sprained ankle
Terminal branch of the common fibular nerve
Deep fibular nerve
The deep fibular nerve arises between the ____ _____ muscle and the ____ ____.
fibularis longus
fibular neck
what artery does the deep fibular nerve join? Where?
anterior tibial artery
between the TA and EDL
What does the deep fibular nerve supply?
all anterior compartment structures
Pathway of the anterior tibial artery:
Begins at the inf border of the popliteus muscle
Passes anterior to interosseous membrane
Descends on the anterior surface of the membrane between the TA and EDL with the deep fibular nerve
Distally, the anterior tibial artery becomes the ____ artery and enters the:
dorsal artery of the foot
the 1st interosseous space
the dorsal artery of the foor divides into what?
the plantar and arcuate arteries
What is the everter compartment?
Lateral compartment of the leg
Lateral surface of the fibula and anterior and posterior intermuscular septa and deep fascia of the leg
lateral compartment of leg
where does the lateral compartment of the leg end?
at the superior fibular retinaculum (runs fom the tip of the fibula to the calcaneus)
OINA for fibularis longus
OR: Head and upper 2/3 fibula
INS: medial cuneiform
Metatarsal 1
AC: Everts foot
Abducts foot
NS: superficial fibular nerve
Long tendon of fibularis longus passes posterior to the ____ ____ and crosses obliquely on the ____ surface of the foot
lateral malleolus
plantar
Lateral malleolus forms a:
trochlea
OINA for fibularis brevis
OR: Distal 2/3 of lateral fibula
INS: Base of metatarsal 5
NS: Superficial fibular nerve
AC: everts and abducts foor
Tendon of the fibularis brevis passes deep to the ____, passes behind the ___ ____ and runs forward to insertion
FL
Lateral malleolus
Main role in ambulation for fibularis brevis:
to balance the tendency toward foot inversion
Arterial supply to the lateral compartment is via perforating branches of:
anterior and posterior tibial arteries proximally, and fibular artery perforators distally
Innervation of lateral compartment muscles
superficial fibular nerve