Lower ExtremityHIP BIOMECHANICS, LUMBOSACRAL PLEXUS, AND LEG MUSCULATURE

Objectives

Describe the gross anatomy for each system (circulatory, muscular, nervous, and skeletal) in the lower extremity.

Integrate the systems to discuss the lower extremity stability and mobility functions.

Analyze common injuries in the lower extremities.

For each muscle, describe how the attachment sites result in an action around a joint.

For each muscle, identify the innervation (peripheral nerve and nerve roots).

Announcements

No office hours Thursday

Lab closed Friday and Monday

Tag Test reminders

Presentations

Which of the following is incorrect pertaining to the patella?

A. It increases the mechanical advantage of the quadriceps femoris for extending the knee.

B. Pain felt deep to it may be associated with a condition known as chondromalacia patella.

C. Testing of its associated tendon reflex is done with the patient sitting and legs "dangling.“

D. It tracks superomedially on the femur. It

increase

s the m

echan

ical a

dv...

Pain fe

lt deep

to it

may be a

sso...

Testi

ng of it

s asso

ciated

tendon ...

It tra

cks s

uperom

edial

ly on th

e...

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Your friend is diagnosed with trochanteric bursitis. You explain to him that this bursa is between the:

A. iliopsoas tendon and the lesser trochanter, allowing the muscle to move freely across the neck of the femur.

B. obturator externus and the lesser trochanter, allowing the muscle to move freely across the trochanter.

C. gluteus maximus and medius at the site of the greater trochanter, allowing the muscles to move freely across one another.

D. skin and the gluteus maximus at the site of the greater trochanter, allowing comfortable sitting by distributing forces across the trochanter.

E. gluteus maximus and the greater trochanter, allowing the muscle to smoothly slide over the trochanter.

iliopso

as tendon and th

e lesse

r ...

obtura

tor e

xtern

us and th

e lesse

...

glute

us maxim

us and m

edius a

t...

skin and th

e gluteus m

axim

us at..

.

glute

us maxim

us and th

e greate

...

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In the following popliteal arteriogram, the arrow points to the:

A. popliteal artery.B. anterior tibial artery.C. fibular artery.D. medial genicular artery.E. fibular recurrent artery.

poplitea

l arte

ry.

anter

ior tibial

arter

y.

fibular arte

ry.

medial ge

nicular a

rtery.

fibular recu

rrent a

rtery.

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In the following coronal MRI of the ankle joint, the arrow points to the:A. plantar

calcaneonavicular (spring) ligament.

B. medial (deltoid) ligament.

C. long plantar ligament.D. abductor hallucis

longus.E. flexor hallucis longus.

planta

r calc

aneonavic

ular (sp

ring..

.

medial (d

eltoid) li

gament.

long plan

tar lig

ament.

abducto

r hall

ucis lo

ngus.

flexor h

allucis

longu

s.

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Leg Musculature

Anterior Compartment

Lateral Compartment

Posterior Compartments Superficial

Deep

Leg muscles primarily act on the ankle AND foot

Malleoli serve as pulleys for tendons

Tendons wrapped in synovial sheaths

Retinacula prevent bowstringing

Anterior Compartment Tibialis anterior

Extensor hallucis longus

Extensor digitorum longus

Fibularis tertius

Lateral Compartment

Fibularis longus

Fibularis brevis

Posterior Compartments

Superficial Triceps surae

Plantaris

Deep Tibialis posterior

Flexor digitorum longus

Flexor hallucis longus

Popliteus

Which of the following is incorrect pertaining to the calcaneal (Achilles) tendon?

A. It is the common distal attachment of the gastrocnemius, and soleus muscles.

B. It continues into the foot as the long plantar ligament.

C. It is used to test S1and S2 nerve function.

D. It is separated from the superior part of the posterior surface of the calcaneus by a bursa.

E. It spirals while passing inferiorly to its attachment on the calcaneus.

It is

the c

ommon dist

al attach

me..

It co

ntinues into

the f

oot as t

he...

It is

used to

test

S1and S2

nerve ...

It is

separat

ed fr

om the su

perior..

.

It sp

irals

while pas

sing i

nferiorly

..

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The tibialis posterior:

A. everts the foot.B. attaches to the femur.C. supports the medial

longitudinal arch of the foot.

D. is an important swing phase muscle.

E. is innervated by the deep fibular nerve. eve

rts th

e foot.

attac

hes to th

e femur.

supports

the m

edial

longit

udinal...

is an

importa

nt swing p

hase m

u...

is inner

vate

d by the deep

fibula...

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Clinical relevance

“Shin splints”

Compartment syndrome

Stress fractures

Clinical relevance cont’d

Foot drop

Your patient is a runner complaining of leg pain. Which of the following can you safely assume is not a likely diagnosis for this patient?

A. Shin splintsB. Tibia stress fractureC. Compartment

syndromeD. Foot drop

Shin sp

lints

Tibia

stress

fractu

re

Compartment s

yndrome

Foot d

rop

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You see a patient in the emergency room with a fibular neck fracture subsequent to an automobile accident. You are fearful that the patient may have severed his common fibular nerve. To determine this, you ask him to walk. Which of the following walking abnormalities would suggest that the nerve has been severed?

A. excessive flexion of the knee at heel-strike

B. shortened stance phaseC. high-stepping (steppage) gaitD. lack of balance (use of a cane)E. lack of effective hallux push-off

exces

sive flexio

n of the k

nee at..

.

shorte

ned stance

phase

high-st

epping (

steppage

) gait

lack of b

alance (u

se of a

cane)

lack of e

ffective

hallux p

ush-o

ff

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