Posterior Leg: Part 2 Flashcards
Deep compartment muscles
- Deep transverse intermuscular septum of the leg
- Separates from superficial
Popliteus (structural classification)
- Partially intracapsular
- Partially extracapsular
- Covered by fascia derived from semimembranosus
Popliteus origin
- Lateral femoral condyle (popliteal groove)
- Posterior aspect of lateral meniscus
Popliteus insertion
- Posterior aspect of proximal tibia, superior to soleal line
Popliteus innervation
- Tibial nerve
Popliteus blood supply
- Posterior tibial artery
- Medial inferior genicular artery
Popliteus function
- Unlocks knee by:
- Laterally rotating femur on tibia
- Medially rotating tibia on femur
Flexor hallucis longus
- Most lateral muscle in deep posterior compartment
Flexor hallucis longus origin
- Inferior 2/3 of posterior fibula
- Intermuscular septum
- Deep fascia
Flexor hallucis longus insertion
- Plantar aspect of base of distal phalanx of hallux
Flexor hallucis longus pathway
- Through groove on posterior tibia/talus
- Inferior to sustentaculum tali, through the flexor retinaculum
- Between fibular/tibial sesamoids
- Inserts plantar aspect of base of distal phalanx (hallux)
Flexor hallucis longus innervation
- Tibial nerve
Flexor hallucis longus blood supply
- Posterior tibial artery
- Fibular artery
Flexor hallucis longus function
- Flex (plantarflex) hallux at interphalangeal and metatarsophalangeal joint
- Can help plantarflex and invert foot
- Important during push-off of gait
Flexor digitorum longus
- Most medial deep compartment muscle
- Tendon is palpable around medial malleolus
Flexor digitorum longus origin
- Posterior tibia, inferior to soleal line
Flexor digitorum longus insertion
- Plantar aspect of the bases of distal phalanges, digits 2-5
Flexor digitorum longus pathway
- Through tibial groove
- Medial to sustentaculum tali, through the flexor retinaculum
- Plantar foot: splits into 4 slips (at cuneiforms)
- Slips pass along plantar surface of lesser metatarsals and phalanges to insertion
Flexor digitorum longus innervation
- Tibial nerve
Flexor digitorum longus blood supply
- Posterior tibial artery
Flexor digitorum longus function
- Flex (plantarflex) digits, distal and proximal interphalangeal joints, and MTPs
- Help with ankle plantarflexion
Flexor digitorum longus tendon crosses
- Superficial to FHL tendon in sole of foot
Master knot of Henry
- Connective tissue between the FHL and FDL
- FHL is dorsal (superior) to FDL
- FDL is plantar (inferior) to FHL
- Inferior to navicular tuberosity
Tibialis posterior
- Deepest muscle of deep posterior compartment
- Tendon is palpable around medial malleolus
Tibialis posterior origin
- Posterior tibia inferior to soleal line
- Posterior aspect of fibula anterior to medial crest
- Interosseous membrane
Tibialis posterior insertion
- Navicular tuberosity
- Plantar aspect of all cuneiforms
- Base of metatarsals 2-4
- Can also insert into plantar aspect of cuboid and 1st,5th metatarsal bases (all tarsals except for talus)
Tibialis posterior pathway
- Posterior to tibia in a groove with FDL
- Inferior to medial malleolus, through the flexor retinaculum
- Passes superior to sustentaculum tali
Tibialis posterior innervation
- Tibial nerve
Tibialis posterior blood supply
- Posterior tibial artery
- Fibular artery
Tibialis posterior function
- Inverts and adducts the foot
- (supinate subtalar and midtarsal joints)
Synovial tendon sheaths of deep compartment muscles
- Flexor hallucis longus sheath
- Flexor digitorum longus sheath
- Tibialis posterior sheath
All proximal synovial tendon sheaths of deep compartment muscles
- Pass within the flexor retinaculum (laciniate ligament)
Flexor hallucis longus PROXIMAL sheath
- Begins about the distal tip of the medial malleolus
- Surround tendon posterior to medial malleolus and inferior to sustentaculum tali
- Ends at knot of Henry
- Begins and ends most distally
Flexor hallucis longus DISTSAL sheath
- Surround tendon from the hallux met head to proximal phalanx
Flexor digitorum longus PROXIMAL sheath
- Begins posterior to medial malleolus, little proximal to FHL sheath
- Ends proximal to master knot of Henry
Flexor digitorum longus DISTAL sheath
- All 4 tendons of digits 2-5 from the metatarsophalangeal joint to middle phalanges