Musculoskeletal Anatomy - Lower Limb Flashcards
Bones, joints, muscles of the pelvic girdle and lower limb
Why are the bones of the lower limb more massive than those of the upper limb?
They are more massive to support the stress of locomotion and greater weight bearing
Why is the pelvis considered a composite structure?
It contains bones of both the axial (sacrum and coccyx) and the appendicular skeleton (hip bones).
Which 3 bones make up each pelvic (aka coxal, innominate, or hip) bone? What cartilage separates them as children?
Ileum, ischium, and pubis. Separated by hyaline cartilage
What differences between the male and female pelvis allow childbirth?
A female pelvis has:
- broader pubic arch, with the angle inferior to the pubic bones generally being greater than 90 degrees
- an enlarged pelvic outlet
- less curvature on the sacrum and coccyx
- wider, more circular pelvic inlet
- relatively broad, low pelvis
- ilia that project more laterally than in the male pelvis
Fully classify the joint between the two pubic bones of the pelvis
Amphiarthrotic cartilaginous symphysis joint
What are 3 functions of the patella
1) strengthen quadriceps tendon
2) protect anterior surface of knee joint
3) serve as anatomical pulley that increases contraction force of quadriceps femoris
Why is the fibula smaller and thinner than other leg bones?
It bears minimal body weight (maybe 10%)
What bony structures make up the ball of the foot?
The phalanges and metatarsal bones
Why does it make sense for the pubic symphysis joint to be partially moveable
Childbirth - the baby’s head and body have to fit through
Fully classify the sacroiliac joint. What cartilage covers the articulating surfaces?
- Diarthrotic synovial multiaxial planar joint
- Hyaline cartilage
Which joint is a common site of lower back pain?
The sacroiliac joint
Fully classify the hip joint and list the movements allowed
Diarthrotic synovial triaxial ball and socket joint
Adduction, abduction, flexion, extension, circumduction, rotation
What are the functions of the medial and lateral menisci of the knee?
1) Act as cushions
2) conform to the shape of articulating surfaces as femur changes position
3) increase surface area of tibiofemoral joint
4) provide lateral stability to the joint
What are the functions of the anterior and posterior cruciate ligaments?
1) limit anterior and posterior movement of femur
2) maintain alignment of femoral and tibial condyles
What is the function of the medial and lateral collateral ligaments and when are they the tightest?
reinforce medial and lateral surfaces of the knee. Tightest when knee is in extension
Fully classify the tibiofemoral joint and list the movements allowed:
- diarthrotic synovial monaxial hinge joint
- flexion, extension, some rotation
Fully classify the talocrural joint and state which movements are allowed:
Diarthrotic synovial monaxial hinge joint
Allows dorsiflexion and plantarflexion.
Fully classify the proximal, middle, and distal tibiofibular joints
Proximal: diarthrotic synovial multiaxial planar joint
Middle: amphiarthrotic fibrous syndesmosis joint
Distal: partial diarthrotic synovial multiaxial planar, partial amphiarthrotic fibrous syndesmosis.