The knee, leg, ankle and foot part 2 Flashcards
Summarise the muscular anatomy of the region
Anterior compartment of the leg
Lateral compartment of the leg
Posterior compartment of the leg
Intrinsic muscles of the foot
Sole – 4 layers
Dorsum – 2 muscles
Which muscles of the anterior compartment of the thigh do not cross the knee joint
Pectineus
Ilio-psoas
Which muscles of the anterior compartment of the thigh cross the knee joint and which knee movement do they cause
Knee extension
Tensor fasciae latae Sartorius Quadriceps femoris Rectus femoris Vastus medialis Vastus intermedius Vastus lateralis
Which muscle from the medial compartment of the thigh acts across the knee joint
Gracilis
Which muscles from the posterior compartment of the thigh act across the knee joint and what movement do they cause
Knee flexion
Semimembranosus
Semitendinosus
Biceps femoris
Summarise the anterior compartment of the leg
Ankle Dorsiflexors (extensors)
Deep Peroneal Nerve
Anterior Tibial Artery
Tibialis Anterior
Extensor Digitorum Longus
Extensor hallucis Longus
Describe the arrangement of the three hamstrings
Biceps femoris lies more laterally (its short head comes from the lateral lip of the linea aspera) and inserts into fibula
Semitendinosus and semimembranosus are more medial and insert into the tibia
Describe the attachments of the tibialis anterior and its function
Proximal: Lateral surface of tibia and adjacent interosseous membrane
Distal: Medial and inferior surfaces of medial cuneiform and adjacent surfaces on base of metatarsal I
Function: Dorsiflexion of foot at ankle joint; inversion of foot; dynamic support of medial arch of foot (I,e during walking)
Describe the attachments of the extensor hallucis longus and its function
Proximal: Middle one-half of medial surface of fibula and adjacent surface of interosseous membrane
Distal: Dorsal surface of base of distal phalanx of great toe
Function: Extension of great toe and dorsiflexion of foot
Describe the attachments and function of the extensor digitorum longus
Proximal: Proximal one-half of medial surface of fibula and related surface of lateral tibial condyle
Distal: Via dorsal digital expansions into bases of distal and middle phalanges of lateral four toes
Function: Extension of lateral four toes and dorsiflexion of foot
Describe the attachments and function of the fibularis tertius
Proximal: Distal part of medial surface of fibula
Distal: Dorsomedial surface of base of metatarsal V
Function: Dorsiflexion and eversion of foot.
Describe the innervation of the anterior compartment of the leg
All innervated by the deep peroneal nerve (L5-S1)
Except tibialis anterior - deep peroneal nerve (L4,5)
Summarise the lateral compartment of the leg
Superficial Peroneal Nerve (L5-S2)
Peroneal Artery
Peroneus Longus
Peroneus brevis
Describe the attachments of the fibularis longus muscle and its function
Proximal: Upper lateral surface of fibula, head of fibula, and occasionally the lateral tibial condyle
Distal: Undersurface of lateral sides of distal end of medial cuneiform and base of metatarsal I
Function: Eversion and plantarflexion of foot; supports arches of foot
Describe the attachments and function of the fibularis brevis
Proximal: Lower two-thirds of lateral surface of shaft of fibula
Distal: Lateral tubercle at base of metatarsal V
Function: Eversion of foot
Describe the passage of the fibularis longus tendon
Distally, the fibularis longus descends in the leg to form a tendon, which, in order:
▪
passes posterior to the lateral malleolus in a shallow bony groove,
▪
swings forward to enter the lateral side of the foot,
▪
descends obliquely down the lateral side of the foot where it curves forward under a bony tubercle (fibular trochlea) of the calcaneus,
▪
enters a deep groove on the inferior surface of one of the other tarsal bones (the cuboid), and
▪
swings under the foot to cross the sole and attach to the inferior surfaces of bones on the medial side of the foot (lateral sides of the base of metatarsal I and the distal end of the medial cuneiform).
passes posterior to fibularis brevis tendon behind lateral malleolus
Describe the passage of the fibularis brevis tendon
The tendon of the fibularis brevis passes behind the lateral malleolus with the tendon of the fibularis longus muscle and then curves forward across the lateral surface of the calcaneus to attach to a tubercle on the lateral surface of the base of metatarsal V (the metatarsal associated with the little toe).
Where does the tendon of the extensor hallucis longus appear
The tendon of the extensor hallucis longus appears between the tendons of the tibialis anterior and extensor digitorum longus in the lower one-half of the leg and descends into the foot.
Which structure does the tibialis anterior go in front of
The medial malleolus
Extensor digitorium longus and fibularis tertius go over lateral malleolus
Summarise the anterior and lateral compartments of the leg
Anterior compartment muscles extend (dorsiflex) the foot at the ankle joint and extend the digits. Supplied by the deep branch of the peroneal nerve.
Lateral compartment muscles evert the foot and can contribute to dorsiflexion.
Summarise the posterior compartment of the leg
Ankle Plantarflexors and flexion of the digits
Tibial nerve
Posterior Tibial Artery
Superficial
Gastrocnemius
Soleus
Plantaris
Deep Popliteus Flexor Digitorum Longus Flexor Hallucis Longus Tibialis Posterior
Superficial and deep compartments separated by a layer of deep fascia
What is important to remember about the superficial group of muscles
As a unit, these muscles are large and powerful because they propel the body forward off the planted foot during walking and can elevate the body upward onto the toes when standing. Two of the muscles (gastrocnemius and plantaris) originate on the distal end of the femur and can also flex the knee.
Describe the attachments and function of the gastrocnemius
Proximal: Medial head—posterior surface of distal femur just superior to medial condyle (just behind adductor tubercle); lateral head—upper posterolateral surface of lateral femoral condyle
Distal: Via calcaneal tendon to posterior surface of calcaneus
Function: Plantarflexes foot and flexes knee
Describe the attachments and function of the plantaris
Proximal: Inferior part of lateral supracondylar line of femur and oblique popliteal ligament of knee
Distal: Via calcaneal tendon to posterior surface of calcaneus
Function: Plantarflexes foot and flexes the knee
Describe the attachments and function of the soleus
Proximal: Soleal line and medial border of tibia; posterior aspect of fibular head and adjacent surfaces of neck and proximal shaft; tendinous arch between tibial and fibular attachments
Distal: Via calcaneal tendon to posterior surface of calcaneus
Function: Plantarflexes the foot
Describe the passage of the plantaris tendon
The short spindle-shaped muscle body of the plantaris descends medially, deep to the lateral head of the gastrocnemius, and forms a thin tendon, which passes between the gastrocnemius and soleus muscles and eventually fuses with the medial side of the calcaneal tendon near its attachment to the calcaneus.