The muscles of the posterior compartment of the thigh are innervated by the tibial (medial) part of the sciatic nerve Except The short head of the biceps is innervated by a branch of the common peroneal nerve.
1. Extension of hip joint. 2. Flexion of knee joint. 3. semimembranous + semitendinosus: medial rotation of leg. 4. Biceps femoris--- lateral rotation of leg.
Action Nerve Supply InsertionOriginMuscle Lateral rotation of leg the tibial (medial) Common peroneal Head of fibula (apex) Low medial Linea aspera 1-biceps femoris, a-long head b-short head Medial rotation of leg the tibial (medial) part Upp part of med s of tibia Low medial 2- semitendinos us Medial rotation of leg the tibial (medial) part Back of med condyle of tibia Upp lateral 3- semimembra nosus
thickest nerve in the body about 2cm in diameter L4, L5, S1, S2, and S3 Inside the pelvis Then leave through greater sciatic Foramen, below piriformis. Descends bet greater troc and ischial tuberosity.
descend to reach popliteal fossa. it divides into 2 terminal branches - Tibial Nerve (med popliteal) -Common peroneal nerve(lat popliteal). Level of division is variable.
1- Muscular Branches Long head of biceps femoris Short head of biceps femoris Semitendinosus Semimembranosus Adductor Magnus (hamstring portion)
2- Articular Branches: To the hip joint To the knee joint
3- Terminal Branches: Tibial Nerve Common Peroneal Nerve
1. Motor loss: - paralysis of hamstrings---- weakness of flexion of knee. - paralysis of muscles of leg- foot----flail foot, foot drop. 2. Sensory loss: on leg and foot except medial side of leg and foot??
When there's pressure on, or inflammation of, the nerve roots, there's usually a burning or electrical- type pain, which can be accompanied by tingling or numbness in the leg or foot.
3. Articular: Sup med inf med, middle genicular n.
Weakness of plantar flexion. Weakness of inversion
Only cutaneous branch of tibial n. Accompanied by small saphenous v. Between 2 heads of Gastrocnemius. Peirces deep fascia
Passes behind below lat malleolus Ends at the lateral side of little toe.
Origin smaller terminal lateral branch of sciatic n L4,5,S1,2. Course & Relations Enters the fossa at its upper angle. follows med border of biceps femoris. leaves fossa at the lat angle of gastrocnemius & soleus. passes behind head of fibula.
winds laterally around neck of fibula pierces peroneus longus deep to peroneus longus divides into 2 terminal branches supf peroneal n deep peroneal n
Branches 1. Cutaneous: a- sural communicating n joins sural n b- lat cutaneous n of calf supplies skin on lat side of back of leg 2. Muscular: short head of biceps femoris
3. Articular: sup, inf lat genicular and recurrent genicular n. 4. Terminal Branches: superficial and deep peroneal n.
Foot drop. WHY? Loss of cutaneous sensation. WHERE?
Common peroneal nerve Tibial nerve smaller terminal lateral L4,5,S1,2 L4,5,S1,2 at sup angle of popliteal fossa. leaves fossa at the lat angle. winds laterally around neck of fibula deep to peroneus longus superficial peroneal n deep peroneal n deep peroneal n Larger branch. L4,5,S1,2,3. Enters pop fossa at upper angle. Leaves at lower angle. Has a triple relation with the pop vessels. At distal border of popliteus---post tibial n
Common peroneal nerve Tibial nerve Cutaneous: sural communicating n lat cutaneous n of calf Muscular: short head of biceps femoris Articular: Sup lat, inf lat genicular, recurrent genicular n. inf lat genicular, recurrent genicular n.Cutaneous: sural n sural nMuscular: To gastrocnemius, plantaris,soleus,popliteu Articular: Sup med Sup med inf med, inf med, middle genicular n. middle genicular n.
Origin: continuation of femoral art as it passes through opening in adductor magnus muscle. Course: from its origin it runs downwards & slightly laterally in popliteal fossa
reaches lower border of popliteus terminates by dividing into ant & post tibial arteries
Formed by union of venae comitantes of ant, post tibial arteries. At the lower border of popliteus. Enters pop fossa at lower angle. Leaves at upp angle. Continues as femoral vein at adductor opening. Lies bet tibial n and pop a. TRIBUTARIES: 1- veines accompany arteries. 2- small saphenous v.
Around termination of small saphenous v. Drain above heel, deep structures of calf. Drain into deep inguinal LNs.