Chapter 9: Muscles of Hip & Lower Limb

The limb is made of how many body segments?

6

How do the 6 spinal nerves innervate?

3 superior and 3 inferior (L2-S2)

What nerve innervates the anterior quadrant of the hip-thigh?

Femoral Nerve L2-L4

-(L2, L3, L4)

What nerve innervates the medial quadrant of the hip-thigh?

Obturator Nerve L2-L4

-(L2, L3, L4)

What nerve innervates the lateral quadrant of the hip-thigh?

Fibular + Gluteal Nerve L5-S2

-(L5, S1, S2)

What nerve innervates the posterior quadrant of the hip-thigh?

Tibial Nerve L5-S2

-(L5, S1, S2)

The Os Coxae is a fusion of what 3 bones?

Ilium, ischium, pubis

Anterior quadrant muscles attach to ______ & are innervated by_______?

Front ilium

Femoral nerve L2-L4

Medial quadrant muscles attach to ______ & are innervated by_______?

Pubis

Obturator nerve L2-L4

Lateral quadrant muscles attach to ______ & are innervated by_______?

Back of ilium

Fibular & gluteal L5-S2

Posterior quadrant muscles attach to ______ & are innervated by_______?

Ischium

Tibial nerve L5-S2

Why do lower limb muscles spiral?

1: Limbs start as little paddles

2: There's a knee and ankle, then

3: The foot turns forward, causing muscles to spiral across the front of the limb

What are the muscles of the anterior hip-thigh quadrant?

1: Iliacus (make up the iliopsoas)

2: Psoas Major (make up the iliopsoas)

3: Sartorius (part of the pen anserinus)

4: Rectus femoris

5: Vastus muscles (medialis, lateralis, intermedius - deep to rectus femoris)

6: 1/2 Tensor Fascia Latte (L4)

What are the attachments of the anterior high-thigh quadrant?

Origin: Anterior Iliac Spine & Femur

Insertion: Patella

What is the action of the anterior high-thigh quadrant?

Flexsion of the hip; Extend the knee

What nerve innveration is for the anterior high-thigh quadrant?

Femoral L2-L4

What are the muscles of the lateral hip-thigh quadrant?

1: 1/2 Tensor Fascia Latae

2: Gluteus muscles (maximus, medius, minimus - deep to gluteus medius)

3: Piriformis - deep to gluteus maximus & medius

What are the attachments of the lateral high-thigh quadrant?

Origin: Posterior ilium (gluteal surface of sacrum)

Insertion: Femur (greater trochanter)

What is the action of the lateral high-thigh quadrant?

Abduction of the hip

What nerve innervation is for the lateral hip-thigh quadrant?

Superior + inferior gluteal or fibular nerve L5-S2

-gluteus maximus: inferior gluteal

-gluteus medias + minimus, tensor fascia latae: superior gluteal

-piriformis: fibular nerve

What are the muscles of the medial hip-thigh quadrant?

1: Pectineus (femoral N.A.V.L covers this)

2: Gracilis

3: Adductor muscles (Longus, Magnus, Brevis - adductor magnus + brevis is deep to adductor longus)

What are the attachments of the medial high-thigh quadrant?

Origin: Pubis

Insertion: Femur (linea aspera)

What is the action of the medial high-thigh quadrant?

Adduction of the hip + medially rotates hip

What nerve innervation is for the medial hip-thigh quadrant?

Obturator L2-L4

What muscles make up the posterior hip-thigh quadrant?

1: Biceps femoris (long + short head - short head is deep to the long head)

2: Semitendinosus (medially situated)

3: Semimembranosus (medially situated)

What are the attachments of the posterior hip-thigh quadrant?

Origin: Ischium (ischial tuberosity)

Insertion: Femur or Tibia & Fibula

What is the action of the posterior hip-thigh quadrant?

Extend the hip; Flex the knee

What is the nerve innervation for posterior hip-thigh quadrant?

Tibial L5-S2 (except biceps femoris short head is innervated by Fibular Nerve L5-S2)

What is the femoral triangle?

A triangle shaped region that separates the anterior quadrants from the medial quadrants

What are the 3 parts to the femoral triangle?

Inguinal Ligament (superiorly)

Sartorius Muscle (laterally)

Adductor Longus (medially)

Where are each 3 parts of the femoral triangle located?

Inguinal Ligament: Superior from anterior superior iliac spine to pubic tubercle

Sartorius Muscle: Lateral edge

Adductor Longus: Medial Edge

What does the femoral triangle include in it?

Nerves

Artery

Vein

Lymphatics

(in that order)

What is the largest muscle group of the body in terms of mass?

Gluteal muscle group

Gluteal muscles can extend the hip, but only if what?

The hip is hyperflexed first

What is included in the suprapiraform portion? (area superior to the piriformis)

Superior gluteal artery, vein, nerve (a., v., n.)

What is included in the infrapiraform portion? (area inferior to the piriformis)

Sciatic nerve (n.)

Inferior gluteal artery, vein, nerve (a., v., n.)

Internal pudendal artery, vein (a., v.)

Pudendal nerve (n.)

What is included in the Lesser Sciatic Foramen?

Internal pudendal artery, nerve (a., v.)

Pudendal nerve (n.)

What is Pes Anserinus?

A place where 3 quadrants come together

-important stabilizer of the medial aspect of the knee joint

What 3 quadrants are included in Pes Anserinus?

Sartorius, Gracilis, Semitendinosus

What is the position of all 3 quadrants of Pes Anserinus?

Sartorius - Superficial to gracilis (anterior - femoral)

Gracilis - Distal to medial condyle of tibia (medial - obturator)

Semitendinosus - Distal to gracilis (posterior - tibial)

What muscles makes up the anterior knee-to-ankle quadrant?

1/2 Tibialis Anterior

What attachment is of the anterior knee-to-ankle quadrant?

Origin: Tibia (lateral condyle)

Insertion: Tarsals/Metatarsals

What action is of the anterior knee-to-ankle quadrant?

Dorsiflexion + Inversion of the foot

What nerve innervates the anterior quadrant of the knee-to-ankle?

Fibular L4-L5 (innervated by the Femoral nerve as well because of L4)

What muscles make up the lateral knee-to-ankle quadrant?

1/2 Tibialis Anterior

Extensor Digitorum Longus

Extensor Hallucis Longus

Fibularis Longus

Fibularis Brevis

What are the attachments of the lateral knee-to-ankle quadrant?

Origin: Fibula

Insertion: Phalanges/Metatarsals

What is the action of the lateral knee-to-ankle quadrant?

Extension of digits + Eversion of foot + Plantar flexion

What nerve innervates the lateral quadrant of the knee-to-ankle?

Fibular L5-S2

What muscle makes up the medial knee-to-ankle quadrant?

1/2 Tibialis Posterior

What is the attachment of the medial knee-to-ankle quadrant?

Origin: Tibia

Insertion: Tarsals/metatarsals

What is the action of the medial knee-to-ankle quadrant?

Plantar flexion + inversion of the foot

What nerve innervates the medial quadrant of the knee-to-ankle?

Tibial L4-L5 (innervated by the Obturator nerve as well because of L4)

What muscles make up the posterior knee-to-ankle quadrant?

1/2 Tibialis Posterior

Gastrocnemius

Soleus (deep to gastrocnemius)

Plantaris

Popliteus

What is the attachment of the posterior knee-to-ankle quadrant?

Origin: Femur

Insertion: Calcanaeus via calcanea tendon/phalanges

What is the action of the posterior knee-to-ankle quadrant?

Plantar flexion + Knee Flexion

What nerve innervates the posterior quadrant of the knee-to-ankle?

Tibial L5-S2

Describe the piriformis muscle & location

Triangle shaped; Under gluteus maximum

What is the location of all 3 gluteal muscles?

Medius: Along the top gluteal surface (iliac crest)

Maximus: Along the back (attached to the sacrum)

Minimus: Deep underneath the medius

The sciatic nerve passes under what muscle?

Gluteus maximus

Why is the gluteus medius muscle important clinically?

Best site for injection because of the large muscle mass. This site is located away from the gluteal arteries as well as the sciatic and gluteal nerves.

What two nerves combine to form the sciatic nerve?

Tibial nerve & fibular nerve

When stuck in heavy traffic you may experience a cramp in the anterior portion of the leg. Why?

There is only one muscle that performs dorsiflexion, but many that do plantar flexion.