Bones of Lower Limb Flashcards
Describe how body weight is transferred to lower limbs.
From vertebral column thru sacro-iliac joints to the pelvic girdle and from there through the hip joints to the femurs and then through the femurs to the knee joints, then from the knee joints to the ankle joint by the tibia, then from the ankle joint to the talus which distributes weight evenly between heel and forefoot when standing
Does the fibula bear weight?
No, it does not articulate with the femur and does not bear weight
Which bone is the keystone of a longitudinal arch formed by tarsal and metatarsal bones of each foot?
The talus
What is the direction of the femurs?
They are oblique, directed inferomedially
Which gender has more oblique femurs?
Females are slightly more oblique than those of males, reflecting the greater width of their pelvis
What bones fuse to form the hip bones?
Ilium, ischium, and pubis
At puberty, what separates these bones?
Triradiate cartilage
When does triradiate cartilage begin to disappear?
15 to 17 years of age
When is fusion complete between these bones?
20 to 25 years of age
Which bone is the superior and largest part of the hip bone?
Ilium
What does the ilium consist of?
Body, and an ala/wing
Which bone forms the poster-inferior part of the acetabulum and hip bone?
Ischium
Which bone forms the anterior part of the acetabulum and anteromedial part of the hip bone?
Pubis
Where do the right and left pubis articulate?
Pubic symphysis
What is the longest and heaviest bone in the body?
The femur
What is the linea aspera?
Prominent double-edged ridge on the posterior aspect of the femur
What is the intertrochanteric line?
Ridge that runs from the greater trochanter to the lesser trochanter
What is the intertrochanteric crest?
Smoother ridge that joins the trochanters posteriorly
What do the femoral condyles articulate with?
Tibial condyles to form the knee joint
What happens to the angle of inclination as we age?
It decreases
What is the range and average adult angle of inclination?
115 to 140 degrees, averaging 126 degrees
Which gender has a lesser angle?
Females have a lesser angle because of the increased width between the acetabula and greater obliquity of shaft
What does the angle of inclination provide?
Greater mobility of the femur at the hip joint because it places the head and neck more perpendicular to the acetabulum
What is the torsion angle?
The intersection between the head and neck of the femur and transverse axis of femoral condyles at the shaft of the femur
What is the mean torsion angle in men and women, respectively?
7 degrees and 12 degrees
What is the significance of the combination of the angle of inclination and torsion angle?
It allows rotatory movements of femoral head within obliquely placed acetabulum to allow for flexion/extension, abduction/adduction, and rotational movements of the thigh
What type of bone is the knee cap?
Sesamoid bone
What does the tibia articulate with?
Superiorly, femoral condyles, the talus inferiorly and the fibula laterally at its proximal and distal ends
What bony projection is formed from the medial side of the distal end of the tibia?
Medial malleolus
Where is the nutrient foramen located?
Posterior aspect of proximal third of tibia
What is the main purpose of the fibula?
To serve as muscle attachment
What bony projection is formed by the distal end of the fibula?
Lateral malleolus
What connects the shafts of the tibia and fibula?
Interosseous membrane
