PHYSCI 107 LECTURE 13 - BONES OF THE LOWER LIMB

What movements are allowed at the hip joint?

flexion/extension

abduction/adduction

rotation

What movements are allowed at the knee?

flexion/extension

What hinge joint is considered to be unstable?

Knee joint

What movements are allowed at the ankle?

pointed up = dorsi flexion

pointed down = plantar flexion

inversion/eversion

What movements are allowed at the toes?

flexion/extension

adduction/abduction

What are the functions of the pelvic girdle?

attaches lower limb to axial skeleton (sacroiliac joint)

supports viscera

What bones make up the pelvis?

innominate bones

What is special about the pelvis with respect to the sexes?

Most sexually dimorphic part of the body

What does the pelvis articulate with posteriorly?

sacrum

What are the three main ossification centers of the innominate bones?

ischium, ilium, pubis

Which ossification center of the innominate bone articulates with the sacrum?

ilium

What are the regions relative to the pelvic brim?

false pelvis - superior (incomplete ring)

true pelvis - inferior (complete ring)

What is the joint that holds the pelvis together?

sacroiliac joint

What is important about the sacroiliac joint w regards to movement?

The sacroiliac joint is synovial which means even though it technically allows for motion, there are a lot of strong ligaments around it so not much can happen

What is the real limiting factor during birth?

The true pelvis (contains hole that baby has to go through)

What is the joint where the two pubis bones meet?

pubic symphysis

What material is found at the pubic symphysis?

fibrous cartilage

What is the function of the fibrous cartilage at the pubic symphysis?

absorb forces while you're walking

What is the socket of the pelvis where the head of the femur attaches?

acetabulum

What limits the movement of the hip joint as compared to the shoulder joint?

it is deeper

What type of cartilage lines the outside of the hip joint?

labrum cartilage

What is characteristic of the attachment at the hip joint that is not present in the shoulder joint?

ligament inside the joint that attaches to the head of the femur

What are the three parts of the lower limb?

thigh, leg, foot

What is the most complex joint in the body?

knee

Which bone is the largest in the body?

femur

What makes the knee joint so complex?

lots of ligaments that help to hold it together

What material are the menisci made of?

fibrocartilage

What are menisci?

little c-shaped structures that sit on top of the tibia at the joint

What are the divisions of the menisci?

lateral and medial

What structures sit in the menisci?

condyles of femur

What is the function of the menisci?

primarily shock absorption

slightly deepens joint

prevents some lateral movement

What are the two types of ligaments in the knee joint?

collateral and cruciates

What is the function of collateral ligaments in the knee joint?

prevent rocking of the joint medially and laterally

Where are the collateral ligaments found?

on either side of the knee joint laterally and medially

What is the function of the cruciates ligaments?

prevent anterior/posterior rocking of the knee joint

Where are cruciates ligaments found in the knee joint?

centrally, deep to the patella

What is the function of the patella?

acts to make a larger moment arm for the quadriceps muscles

Protects tendons of quadriceps and makes them stronger by giving it better torque

the muscles help extend the knee

What type of angle is created at the knee joint?

Q angle

What is the function of the Q angle?

puts leg underneath the body so that it can actually support its weight

What are bursae in the knee?

fluid-filled sacs around the joint to protect the ligaments/tendons of the knee joint

What is the unhappy triad of the knee joint?

Damage caused by a lateral blow to the knee in the ACL, tibial collateral ligament, and medial meniscus

Which lower leg bone is medial and which is lateral?

Tibia - medial

Fibula - lateral

Which bone of the lower leg carries most of the weight?

Tibia

Which bone of the ankle allows for dorsi/plantar flexion?

talus

Which joint is known as the "true ankle joint?"

joint between talus and tibia/fibula

What type of joint is the "true ankle joint?"

hinge joint

Which bone of the ankle is the heel bone?

calcaneus

What joints allows for inversion/eversion at the ankle joint?

transverse tarsal joints

subtalar joints

Where are transverse tarsal joints found?

between talus and navicular

between calcaneus and cuboid

Where is the subtalar joint found?

"below talus"

between talus and calcaneus

What is the usual location for amputation of the foot and why?

transverse tarsal joints because it provides a flat plane for the amputation to occur

What is the scientific name for the big toe?

hallux

What is formed by the metatarsals and phalanges?

arch of your foot

What structures actually hit the ground when you walk?

calcaneal tuberosity and anterior end of metatarsals

What are the subdivisions of the arch of your foot?

transverse and longitudinal

How does the arch of your foot assist in walking?

cushioning and storing energy

as you walk, your arch flattens, which stretches the ligaments, which spring back as you lift your foot

What structures maintain the arch of your foot?

4 ligaments (plantar aponeurosis, short plantar ligament, long plantar ligament, plantar calcaneonavicular ligament)

Which ligament is responsible for the 'spring' when walking?

plantar calcaneonavicular ligament