Lower Limb III and IV Flashcards
Muscles of the posterior compartment of the thigh action and names
Extend the thigh and flex the leg
Semitendinosus, semimembranosus, and biceps femoris
(And Hamstring head of adductor Magnus muscle)
Semitendinosus muscle: origin, insertion, innervation, action
Ischial tuberosity Medial part of proximal tibia Tibial division of the sciatic nerve Extends thigh, flex leg, medially rotates leg *huge tendon of origin
Semimembranosus muscle
Ischial tuberosity Medial condolences of the tibia Tibial division of the sciatic nerve Extend thigh, flex and medially rotate the leg *huge tendon of insertion
Biceps femoris: long head
Ischial tuberosity
Head of fibula
Tibial division of the sciatic nerve- (because it comes off of the ischial tuberosity)
Extends thigh, flexes and laterally rotates the leg
Biceps femoris: short head
Linea aspera
Head of fibula
Common fibular division of the sciatic nerve (because it comes off of the femur)
Extends the thigh, flexes and laterally rotates the leg
Nerve supply to the posterior compartment of the thigh
Sciatic nerve (L4, 5, S1, 2, 3)- splits into tibial and common fibular (Peroneal) nerve Posterior femoral cutaneous nerve (S1, 2, 3) (medial to sciatic) innervates the skin of posterior thigh and over popliteal fossa
Blood supply to muscles of the posterior thigh
Perforating Arteries of the profunda femoris enter the posterior compartment and provide muscular branches to the hamstrings
Bursa
Sacs that secrete synovial fluid anywhere there is friction over bone by a tendon, muscle, etc
Clinical significance- can become inflamed or irritated “bursitis”
Pes anserinus
Three conjoined tendons on the medial aspect of the knee
From anterior to posterior: sartorius, gracilis, semitendinosus
Clinical significance: pes anserinus bursa lies between the pes anserinus tendons and the more deeply located semimembranosus tendon; can become inflamed (pes anserinus bursitis)
3 different nerves supplying these muscles: femoral n, obturator n, and tibial nerve, resp.
Adductor magnus: adductor part
Ischiopubic ramus (pubicfemoral portion)
Shaft of the femur
Obturator nerve
Adducts/flexes the thigh
Adductor Magnus: hamstring part
Ischial tuberosity (ischocondylar portion)
Adductor tubercle of femur (where the adductor hiatus is)
Tibial division of the sciatic nerve
Adducts and extends the thigh
Capsule of the knee joint extends from:
And is strengthened by:
Femur to tibia
Fibers of the fascia lata, IT tract, tendons of the vasti, hamstrings, and sartorius muscles
*fascia lata becomes the cural fascia to strengthen
patellar ligament extends from and helps:
Apex of the patella to the tuberosity of the tibia; helps hold the patella in place and serves as part of the “tendon” of the quadriceps femoris muscle
Oblique popliteal ligament extends from and reinforces:
Lateral femur to the posterior tibia to reinforce posterior surface of the joint capsule
Extension of the semimembranosus*
Arcuate popliteal ligament extends from and acts to:
Lateral condolences of the femur to the head of the fibula to arch over the tendon of the popliteus muscle; stabilize the posterior aspect of the knee
Anterior cruciate ligament extends from and acts to:
The front of the intercondylar eminence to the medial surface of the lateral femoral condyle posteriorly
Checks extension and anterior slipping of the tibia on the femur (or posterior displacement of the femur on the tibia)
Posterior cruciate ligament extends from
Posterior intercondylar fossa and to the lateral surface of the medial femoral condyle anteriorly
Checks flexion and posterior slipping of tibia on the femur (or anterior displacement of the femur on the tibia)
Medial meniscus
Crescent shaped; Cartilaginous structure Attached to the tibia anterior to the ACL and to the posterior intercondylar area
Deepens the medial tibial condyle; the medial (tibial) collateral ligament is firmly attached to the medial meniscus
Not very mobile
Lateral meniscus
Nearly circular, attached to the tibia anterior to the ACL; posteriorly attached behind the intercondylar eminence anterior to the medial meniscus
Has more movement because it has no attachment to the lateral (fibular) collateral ligament
Functions of the menisci
Deepen the tibial plateaus to accommodate the femoral condyles
Medial/tibial collateral ligament
Broad flat band located slightly posterior on the medial side of the knee. Attached proximally to the medial epicondyle of femur right below adductor tubercle. Distal attachment to the medial condyle of the tibia.
Resists forces that would push the knee joint medially. Fused to the medial meniscus
Lateral/Fibular collateral ligament
Rounded, more narrow and less broad than medial collateral ligament. Stretches downward from lateral epicondyle of femur to the head of the fibula. Not fused with lateral meniscus, so it is less susceptible to injury*
The popliteal fossa is bounded by
Superolaterally- biceps femoris muscle
Superomedially- semimembranosus and semitendinosus muscles
Inferolaterally and inferomedially- the lateral and medial heads of the gastrocnemius muscle
Posteriorly- skin and the popliteal fascia form the roof
when the femoral artery and vein come out of the adductor hiatus, they are renamed:
What covers the entrance of the femoral vessels into the popliteal fossa (adductor hiatus)
Exits hiatus (posterior) to become the Popliteal artery and vein Intermuscular septum (saphenous nerve passes under this instead of the adductor hiatus)
Contents of the popliteal fossa
Termination of the small saphenous vein
Popliteal artery and vein (continuation of the femoral vessels)
Tibial and common fibular nerves (divisions of sciatic nerve)
Posterior cutaneous nerve of the thigh
Popliteal lymph nodes and lymphatic vessels
Plantaris muscle
Lateral side of the distal femur Calcaneal tendon Tibial nerve Weak plantarflexion VERY long tendon, muscle belly is high up, but action is way below
Popliteus muscle
Lateral epicondyle of femur Posterior surface of the proximal tibia Tibial nerve Weakly flexes knee; unlocks extended knee Passes under the ACL
Interosseus membrane
Strong, fibrous sheet that connects the interosseous margin of the tibia and the interosseus margin of the fibula, filling the gap between the two bones except at the proximal and distal ends where there exists openings in the membrane that allow for the passage of vessels.
Stabilizes the tibiofibular junction and provides attachment for many of the leg muscles and transmits force down the leg
Joints of the ankle and foot- names, types and actions
Talocrural joint (hinge jt at ankle)- dorsiflexion and plantarflexion. Medial malleolus of tibia and lateral malleolus of fibula and talus. Subtalar joint (talocalcaneal, gliding jt.)- inversion and eversion
- dorsiflexion (Dorsum or top of the foot up) and plantarflexion (plantar or bottom of the foot points back)
- inversion (plantar surface faces in/medially) and eversion (plantar surface faces out)
Lateral collateral ligament (complex) of the ankle
Set of three ligaments that resists inversion of the ankle joint: posterior talofibular ligament, anterior talofibular ligament, calcaneofibular ligament.
More commonly injured than the medial collateral (deltoid) ligament of the ankle
Run from the lateral malleolus to the talus and calcaneus
Deltoid (medial) ligament of the ankle
Attaches the medial malleolus to multiple tarsal bones to stabilize the side of the ankle joint and prevent excessive eversion of the ankle
Anterior parts of the ligament limit plantar flexion and posterior parts of the ligament limit dorsiflexion
What divides the leg into its posterior deep and superificial compartments?
Intermuscular septum