Frolich, Human Anatomy, Lower LImb

Lower Limb

Skeleton (homologous with upper limb)

Muscles--anterior, posterior compartments

Nerves--sciatic, femoral

Surface anatomy

What is a limb? Skeleton Joints Pelvis or limb girdle Hip/Hip Muscles Lumber and sacral

plexus—getting spinal nerves out onto limb

Muscles—anterior and posterior compartments

Surface anatomy

Frolich, Human Anatomy, Lower LImb

What is a limb? Ventral somatic outgrowth of

outer tube Bones (made of bony tissue,

cartilage, and other tissues) Joints Muscles Nerves (with motor neurons to

muscles, sensory neurons to skin, proprioceptors)

No viscera--all innervation is somatic (motor or sensory) from ventral ramus of spinal nerve (except autonomics to blood vessels)

Frolich, Human Anatomy, Lower LImb

Upper Limb

Scapula Humerus Radius, ulna Carpals Digits

Metacarpals Phalanges

Lower Limb

Pelvis Femur Tibia, fibula Tarsals Digits

Metatarsals Phalanges

Frolich, Human Anatomy, Lower LImb

Scapula Humerus Radius, ulna Carpals Digits

Metacarpals Phalanges

Upper Limb

Frolich, Human Anatomy, Lower LImb

Frolich, Human Anatomy, Lower LImb

Tibia/fibula

Tibia--big toe side Fibula--little toe side

(no pronation/supination)

Frolich, Human Anatomy, Lower LImb

Ankle

Talus--forms ankle joint

Calcaneus--forms heel

Frolich, Human Anatomy, Lower LImb

Foot Function: Support weight Act as lever when walking

Tarsals Talus = ankle

• Between tibia + fibula• Articulates w/both

Calcaneus = heel• Attachment for Calcaneal

tendon• Carries talus

Metatarsals Homologous to metacarpals

Phalanges Smaller, less nimble

Frolich, Human Anatomy, Lower LImb

Joints of Lower Limb

Hip (femur + acetabulum) Ball + socket Multiaxial Synovial

Knee (femur + patella) Plane Gliding of patella Synovial

Knee (femur + tibia) Hinge Biaxial Synovial

Frolich, Human Anatomy, Lower LImb

Joints of Lower Limb

Proximal Tibia + Fibula Plane Gliding Synovial

Distal Tibia + Fibula Slight “give” Fibrous

Ankle (Tibia/Fibula + Talus) Hinge Uniaxial Synovial

pg 218

Frolich, Human Anatomy, Lower LImb

Lower Limb Movements Hip

Flexion/extension Abduction/adduction Lateral/medial rotation

Knee Flexion/extension

Ankle Dorsiflexion/plantarflexion Inversion/eversion

Toes Flexion/extension

Bending on posterior side is flexion (except hip)

Bending on anterior sided is extension (except hip)

Frolich, Human Anatomy, Lower LImb

Pelvic tilt and a reverse lumbar curve

(or how we got to be upright)

Bowl concept pelvis spills forward Hernia “beer belly” In human minor pelvis is

behind (posterior) to guts and abdominal cavity

Compare human pelvic position with quadruped (cat for instance)

Frolich, Human Anatomy, Lower LImb

Human pelvis still has quadruped orientation

Frolich, Human Anatomy, Lower LImb

Bony structure of the pelvis

MAIN STRUCTURES Hip bone (innominate,

os coxae)--fusion of Ilium (“hips”) Ischium (“rear”) Pubis (anterior midline)

Sacrum and coccyx Acetabulum Femur--head, neck,

greater trochanter

HOLES False and true pelvis

(major, minor pelvis) Pelvic inlet, pelvic outlet Sacrotuberous ligament Sacrospinous ligament Greater, lesser sciatic

foramen Obturator foramen

Frolich, Human Anatomy, Lower LImb

Frolich, Human Anatomy, Lower LImb

Female Male

Cavity is broad, shallow Pelvic inlet oval + outlet round Bones are lighter, thinner Pubic angle larger Coccyx more flexible, straighter Ischial tuberosities shorter,

more everted

Cavity is narrow, deep Smaller inlet + outlet Bones heavier, thicker Pubic angle more acute Coccyx less flexible, more curved Ischial tuberosities longer, face

more medially

Frolich, Human Anatomy, Lower LImb

Posterior and lateral hip

Gluts (gluteal nn.) Maximus—extensor of thigh Medius--pelvic tilt (relative to

insertion with foot planted) Lateral rotators (spinal nn.)

Piriformis syndrome

Frolich, Human Anatomy, Lower LImb

Anterior Hip

Iliopsoas iliacus psoas

Quadratus lumborum

Frolich, Human Anatomy, Lower LImb

Lumbar and sacral plexus

Mr. Bill is happy—so easy

Lumbar plexus forms femoral n.—anterior

Sacral plexus forms sciatic n.--posterior

Femoral n.

Sciatic n.

Frolich, Human Anatomy, Lower LImb

Lumbar plexus (femoral nerve)

Sacral plexus (sciatic nerve)

With leg out to side like quadruped, lumbar-anterior, sacral-posterior makes sense

Frolich, Human Anatomy, Lower LImb

Dermatomes show twisting of leg during development

Dorsal becomes anterior: thus “dorsiflexion” and extension in anterior compartment (unlike upper limb)

Ventral becomes posterior: thus flexion is in posterior compartment (unlike upper limb)

Frolich, Human Anatomy, Lower LImb

Anterior/Posterior compartments

ANTERIOR COMPARTMENT

POSTERIOR COMPARTMENT

MOVEMENT Extension Flexion

MUSCLES Quads

Shin

Hamstrings

Gastrocs

NERVES Femoral n.

(lumbar plexus)

Sciatic n.

(sacral plexus)

Frolich, Human Anatomy, Lower LImb

Thigh movements by compartment

Frolich, Human Anatomy, Lower LImb

Anterior thigh (femoral n.)

Sartorius (Tailor’s muscle)

Quads (four) Rectus femoris

(crosses hip) 3 vastus mm.

(vast--big)

Frolich, Human Anatomy, Lower LImb

Posterior thigh (sciatic n.) Hamstrings

Biceps femoris Semimembranous Semitendinous

Frolich, Human Anatomy, Lower LImb

Medial thigh (obturator n.)

Adductor muscles Gracilis Adductor

• Magnus• Longus• brevis

Frolich, Human Anatomy, Lower LImb

Leg movements by compartment (in leg all nn are branches of sciatic)

Frolich, Human Anatomy, Lower LImb

Anterior Leg (deep fibular n.)

Extensors (dorsiflexors) Fibularis (peroneus)

longus Extensor digitorum

longus Extensor hallicus longus Tibialis anteriorus

Frolich, Human Anatomy, Lower LImb

Lateral Leg (superficial fibular n.)

Fibularis brevis/longus

Frolich, Human Anatomy, Lower LImb

Posterior Leg (tibial n.)

Flexors (plantarflexors) Gastrocs and

soleus Flexor digitorum

longus Flexor hallucus

longus

Frolich, Human Anatomy, Lower LImb

Human gait

Humans only large mammal marathoners, ultra-runners

Prehistoric cultures hunted by exhausting large prey

Bipedalism very efficient energetically

Gastroc-Achilles spring One other large mammal

more efficient—also bipedal

Frolich, Human Anatomy, Lower LImb

Intrinsics of foot

Frolich, Human Anatomy, Lower LImb

Surface Anatomy: Anterior Thigh + Leg

Palpate Patella Condyles of femur

Femoral Triangle Sartorius (lateral) Adductor longus (medial) Inguinal ligament

(superior) Femoral a + v, lymph

nodes

pg 785

pg 792

Frolich, Human Anatomy, Lower LImb

Surface Anatomy: Posterior Leg

Popliteal fossa Diamond-shape fossa

behind knee Boundaries

Biceps femoris (sup-lat) Semitendinosis +

semimembranosis (sup-med)

Gastrocnemius heads (inf) Contents

Popliteal a + v

Calcaneal (Achilles) tendonpg 793

Frolich, Human Anatomy, Lower LImb

Blood supply to lower limb

Internal Iliac Cranial + Caudal Gluteals= gluteals Internal Pudendal = perineum, external

genitalia Obturator = adductor muscles

External Iliac Femoral = lower limb

• Deep femoral = adductors, hamstrings, quadriceps

Popliteal (continuation of femoral) • Geniculars = knee• Anterior Tibial = ant. leg muscles, further

branches to feet• Posterior Tibial = flexor muscles, plantar

arch, branches to toes