The Lower ExtremityBIOL 1010

FEMUR

TIBIA

FIBULA

ERROR:

#7 is CUBOID#4 is LATERAL CUNEIFORM

Very similar to the upper extremitySome definitions: a. Thigh part from the hips to knees b. Leg part from the knee to the ankleNote that the hip joint is a ball and socket joint. It allows movement in all direction. The knee only allows flexion and extension not circumduction. It is never normal for hyperextension of knee (genu recurvatum)

In humans, the abdominal aorta terminates into the common iliac arteries.

The common iliacs divide into the external and internal iliacs.

In humans, the aorta terminates as the middle sacral artery.CAT

The nerves of the lower extremity are simpler than the upper limb. There are three nerves entering the thigh. Their lateral branches serve the gluteal muscles.

femoral nerve L2,3,4 anterior compartmentobturator nerve L2,3,4 medial compartmentsciatic nerve L4,5,S1,2,3 (sacral plexus) posterior compartment

The only one of the three that travel below the knee is the sciatic nerve.The sciatic nerve branches into two nerve: 1. tibial nerve 2. common peroneal nerve a. Superficial peroneal nerve b. Deep peroneal nerve

femurmediallateralAnterior compartment-Extensors of the kneeFemoral NerveMedial compartment-Adductors of the kneeObturator NervePosterior compartment-Flexors of the kneeSciatic Nerve

The anterior compartment of the thigh is homologous to the posterior compartment of the arm.The posterior compartment of the thigh is homologous to the anterior compartment of the arm.

The leg has three compartmentsAnterior compartment - dorsiflexors (flexors) of the foot - deep peroneal nervePosterior compartment - plantarflexors (extensors) of the foot - tibial nerveLateral compartment - extensors of the foot - superficial peroneal nerve

The FASCIA LATA (not to be confused with the muscle of similar name) is connective tissue on the lateral side of the femur. This forms the ILIOTIBIAL BAND. This band connects the ilium and tibia and is the site of inflammation in runners iliotibial band syndrome.

Muscles of the Medial Compartment of the ThighObturator Nerve

Muscles of the Posterior Compartment of the ThighTibial portion of Sciatic Nerve

Muscles of Anterior Thigh*Femoral Nerve

1.Semitendinosus2. Biceps Femoris3. Caudofemoralis4. Gluteus Maximus5.Gluteus Medius6. Tensor Fascia Lata7. Sartorius

The rectus femoris cross two joints, therefore it has actions on the two joints involved.The patella is articulates with the FEMUR, not the tibia.The patella is attached to the femur and tibia by the PATELLAR LIGAMENT. When this ligament is pulled, the patella is lifted superiorly and brings the leg into an extended position.In the posterior leg, the GASTROCNEMIUS muscle is responsible for plantarflexion. It originates at the femur and inserts on the posterior surface of the calcaneus. It crosses two joints so it can flex the knee and plantarflex (extend) the foot. It is innervated by the tibial nerve.

L2L3L4iliopsoasRectus femorispectineusVastus medialisVastus intermediussartoriusVastus lateralisMotor Branches of the Femoral Nerve

Adductus magnusgracilisAdductor longusAdductor brevisMotor Branches of the Obturator Nerve

L4L5S1S2S3SemitendinosisBiceps femorissemimembranosusHamstringsGastrocnemius and posterior compartment of the leg and footTibial nerveCommon peroneal nerveDeep peroneal nerveAnterior compartment of legLateral compartment of legSuperficial peroneal nerveMotor Branches of the Sciatic Nerve

calcaneustaluscuboidnavicularMedial, intermediate, and lateral cuneiformsmetatarsalsphalangesThe Foot

Anterior Leg Structures - SuperficialIdentify the Following:

Tibialis AnteriorPeroneus LongsPeroneus BrevisExtensor Digitorum LongusPatellar TendonPatellaTibiaPeroneus TertiusExtensor Hallucis LongusPopliteus TendonSartorius Tendon

Posterior Leg Structures - SuperficialIdentify the Following:

FemurTibiaFibulaSoleusAchilles TendonPlantarisPopliteusCalcaneus

Posterior Leg Structures - DeepIdentify the Following:

Achilles TendonFlexor Hallucis LongusFlexor Digitorum LongusCalcaneusTalusTibiaFibulaFemur

Intrinsic Muscles of the FootThese muscles all originate and insert on foot bones.They help to flex, extend, abduct, or adduct the toes.All the intrinsic muscles of the foot are found on the plantar surface (except the one on the dorsal aspect).The plantar muscles are arranged in 4 layers, from superficial to deep.

Intrinsic Muscles of the Foot