Lecture 3 Flashcards
Name structure A
Soleal line (Found on posterior Tibia)
How does the Closed chain screw-home mechanism work
Lock/Straighten- Knee Locks by medially ROTATING FEMUR on flexed tibia to allow extension of the knee
Unlock/Bend- POPLITEUS CONTRACTS, laterallly ROTATING FEMUR on fixed tibia, so flexion can occur
How does the open chain screw home mechanism work?
Lock/Straighten - Tibia rotates laterally on fixed femur to allow extension of knee
Unlock/Bend- POPLITEUS CONTRACTS - medially rotates tibia on fixed femur so flexion can occur
How does the Popliteus unlock the knee the screw home mechanism?
Closed chain- Laterally rotates femur on fixed tibia
Open chain- Medially rotates tibia on fixed femur
What is the innervation of the Gastrocnemius + Soleus + Plantaris?
Tibial Nerve S1 S2 for all 3 superficial layer lower leg muscles
What is the Origin of the Gastrocnemius?
Medial head originates : Poplieal surface of femur; superior to medial condyle
Lateral head originates- Lateral aspect of lateral condyle of femur
What are the actions of the Gastrocnemius?
Plantarflexes ankle joint when knee extended
Raises heel during walking
Flexes Knee joint
What is the insertion of the Gastrocnemius?
Calcaneus via the Calcaneal Tendon
What is the Origin of the Soleus?
Posterior Fibula
Soleal line + Medial Tibia
Tendinous arch extending between boney attachments
What’s the insertion of the soleus AND Plantaris?
The Calcaneus via the Calcaneal tendon (Same insertion as gastrocnemius)
What is the action of the soleus?
Plantarflexes anklejoint independent of knee position
Stabilizes ankle joint
What is the Origin of the Plantaris?
Lateral Supracondylar line of femur
Oblique Popliteal ligament
What are the muscle actions of the Plantaris?
Weakly assists gastrocnemius in plantarflexing ankle joint
What is the muscle action of the Popliteus?
unlocks knee joint by rotating femur 5 degrees on fixed tibia
Medially rotates tibia of unplanted limb
What is the origin of the Popliteus?
Lateral Condyle of Femur and Lateral Meniscus
What is the insertion of the popliteus?
Posterior Tibia above Soleal line
What’s the innervation of the Popliteus?
Tibial Nerve L4 L5 S1
What’s the innervation of the Flexor Hallicus Longus?
Tibial Nerve S2 S3
What is the origin of the Flexor Hallicus Longus?
Lower Posterior Surface of fibula and Interosseus membrane
What is the insertion of the Flexor Hallucis Longus?
Base of distal phalanx of great toe (Hallux)
What is the muscle action of the Flexor Hallicus Longus?
Flexes great toe at all joints
Weakly Plantarflexes Anklejoint
Supports Medial Longitudinal arch of foot
What is the origin of the Flexor Digitorum Longus?
Posterior Tibia inferior to Soleal line
Attaches to the Fibula by a broad tendon
What is the insertion of the Flexor Digitorum Longus?
Base of the distal phalanges of the lateral 4 digits
What is the innervation of the Flexor Digitorum Longus?
Tibial Nerve S2 S3
Where does the Sciatic nerve split?
Behind the hamstring
What is the muscle action of the Flexor Digitorum Longus
Flexes lateral four digits
Planterflexes ankle joint
Supports (BOTH) Longitudnal arches of foot
What is the origin of the Tibialis Posterior
Interosseus Membrase
Posterior Tibia inferior to Soleal line
Posterior surface of fibula
***ONLY MUSCLE THAT ATTACHES TO ALL 3 STRUCTURES POSTERIORLY
What is the insertion of the Tibialis Posterior (A lot)
Tuberosity of Navicular
Cuneiform
Cuboid
And Sustenaculum of Tali and Calceneus
Base of 2 3 and 4 metatarsals
What is the innervation of the Tibialis Posterior
Tibial Nerve L4 L5
What is the muscle action of the Tibialis Posterior
Plantarflexes ankle joint
Inverts foot
Maintains Medial Longitudinal Arch
What is the Origin of the Fibularis Brevis?
Inferior Lateral Fibula
What is the innervation of the Fibularis Brevis and Longus
Superficial Fibular Nerve (L5 S1) S2
They’re the only muscles that get the superficial fibular nerve!
What is the insertion of the Fibularis Brevis?
Lateral Side of the base of the 5th Metatarsal