Anatomy of leg and foot Flashcards
What are the functions of the foot?
- support body weiight
- stability/standing
- locomotion/propulsion (lever)
- shock absorption
State the names of the bones of the foot
Tarsals: Calcaneus, talus, cuboid, navicular, medial cuneiform, middle cuneiform, lateral cuneiform
Metartarsals
(Sesamoid bones)
Phalanges
What movements are permitted by the foot/
- dorsiflexion/extension
- plantarflexion/flexion
- eversion
- inversion
- supination (feet together on irregular surface)
- pronation (feet apart on irregular surface)
What movements are permitted by the joints of the foot?
Ankle joint- dorsi/plantarflexion
Intertarsal joints- invert/evert, supinate/pronate
MTP joints- extension/flexion, limited abduction/adduction
IP joints- extension/flexion
What kind of joint is the ankle?
Which bones form its articulation?
Articulation between the throchlea of the talus and the lateral malleolus (fibula) and medial malleolus (tibia)
Synovial hinge joint
Which ligaments stabilise the ankle?
What happens in injury?
- Lateral collateral ligament from lateral malleolus to talus and calcaneus
- Medial collateral ligament from medial malleolus to talus, calcaneus and navicular
- Injury to lateral ligament (usually anterior talofibular ligament)
The subtalar joint is between which bones?
Allows for which movements?
- between talus and calcaneus (+ navicular)
- allows inversion and eversion during locomotion
The transverse tarsal joint is between which bones?
Allows for which movements?
Between calcaneus/talus and cuboid and navicular
Allows eversion and inversion, pronation and supination
- Important for standing on uneven ground
What is the plantar aponeurosis?
Clinical significance?
- Thickening of deep fascia which protects underlying structure and supports longitudinal arch
- Originates from calcaneus with longitudinal bands to toes
- Plantar fasciitis is inflammation due to overuse
Briefly describe the arches of the foot and their functions
- Longitudinal and transverse arches
- shock absorbers during locomotion
- act as springboards
- distribution of weight (to calcaneus + ball of foot)
Which longitudinal arch is most defined?
How are the longitudinal arches supported?
What is the clinical relevance of them?
Medial longitudinal arch is most defined
- Supported by long tendond, intrinsic plantar muscles, intrinsic ligaments and plantar aponeurosis
- Fallen medial longitudinal arch can lead to pes planus (flat feet)
Where is the transverse arch?
What structure supports the transverse arch?
Base of metatarsals
- Supported by long tendons (mainly fibularis longus)
For each muscle compartment of the leg state:
- function
- innervation
Anterior
- dorsiflexion, inversion
- deep fibular nerve
Posterior
- plantarfllexion, invert
- tibial nerve
Lateral
- evert foot
- superficial fibular nerve
State the three muscles of the anterior compartment, their origin, insertion and innervation
Tibialis anterior
- origin: tibia
- dorsiflexion/invert foot
Extensor digitorum longus
- fibula
- extends lateral 4 toes
Extensor hallucis longus
- fibula
- extends great toe
Insert into flexor retinaculum
Supplied by deep fibular nerve
In the foot, outline the insertion of the extensor tendons of the anterior compartment of leg
Tibialis anterior
- medial cuneiform and 1 st metartarsal
Extensor digitorum logus
- middle and distal phalanges of toes 2-5
Extensor hallucis longus
- distal phalanx of great toes
Consider the superficial muscles of posterior compartment of the leg
State their names, origins, insertions, function and innervation
- Plantarflex foot and leg
- Gastrocnemius
- from femoral condyles - Soleus (under gastroc)
- from tibia and fibula - Plantaris (medial to soleus)
- from femur
Insert into tendo calcaneus (achilles tendon)
Innervated by tibial nerve
Consider the deep muscles of posterior compartment of the leg
State their names, origins, insertions, function and innervation
- Innervates by tibial nerve
- Insert into flexor retinaculum
- Tibialis posterior
- origin: tibia
- inverts foots - Flexor digitorum longus
- origin: fibula
- flexes lateral 4 toes - Flexor hallucis longus
- origin: fibula
- flexes great toes
In the foot, outline the insertion of the flexor tendons of the posterior compartment of leg
- Tibialis posterior inserts into medial cuneiform and navicular
- Flexor digitorum longus inserts into distal phalanges
- Flexor hallucus longus inserts into distal phalanx of great toes
Consider the lateral compartment of the leg
Which muscles comprise it?
Origin and insertion?
Function?
Innervation
- Fibularis longus
- everts and plantarflexes foot
- maintains transverse arch - Fibularis brevis
- everts foot
From fibula to fibular retinaculum
Supplied by superficial fibular nerve
In the foot, outline the insertion of the tendons of the lateral compartment of leg
- Fibularis longus inserts into medial cuneiform and 1st metartarsal
- Fibularis brevis inserts into 5th metatarsal
What protective covering coats the long flexor tendons of the foot ?
Synovial sheaths
Describe the intrinsic muscles of the foot
Form many layers
- dorsal extensors form 1 layers
- plantarflexors/abductors/adductors form 4 layers
Outline the blood supply to the posterior compartment
Popliteal artery –> ant/posterior tibial artery
What is the contents of the tarsal tunnel?
Clinical relevance?
- Tibialis posterior, flexor digitorum longus, posterior tibial artery and vein, tibial nerve, flexor hallucis longus
- Pulse
Outline the arterial supply to the base of the foot
Posterior tibial artery gives off medial and lateral plantar artery
Lateral plantar artery forms deep plantar arch
Where is dorsalis pedis?
Originates from?
Form anastomisis with?
Clinical relevance?
Between tibialis anterior (laterally) and extensor hallucis longus tendon (medially)
From anterior tibial artery
Forms anastomoses with deep plantar arch
PULSE
Innervation of the leg is supplied by terminal branches of which nerve?
Sciatic
Tibial nerve supplies which muscles?
Branches?
Clinical relevance?
- Posterior compartment of leg and plantar intrinsic muscles (via medial and lateral plantar nerves)
- Tarsal tunnel syndrome
Common fibular nerve supplies which muscles?
Clinical relevance?
- Deep fibular nerve supplies anterior compartment of leg and dorsal intrinsic muscles
- Superficial fibular nerve supplies lateral compartment of leg
- Trauma to common fibular nerve –> foot drop
Describe the cutaneous nerves of the leg and foot
ANTERIOR
- Upper lateral leg- common fibular
- Lower lateral leg- superficial fibular
- Little toe- sural
- Dorsum of foot and middle toes - superficial fibular nerve
- Space between big toe and 2nd toe- deep fibular nerve
- Medial side of foot and leg - saphenous nerve
POSTERIOR
- Sural nerve
