Limbs 3 Flashcards
What are the two major regions of the lower limb?
- gluteal region (buttock and hip)
- free lower limb (thigh, leg and foot)
What is the leg?
The area between the knee and the ankle
What is the gluteal region homologous to in the upper limb?
The pectoral girdle
What is the knee joint homologous to in the upper limb?
The elbow joint
Why do the homologous actions between the upper and lower limb appear so different?
Developmental differences in the arrangement of muscle groups
How does flexion differ between the elbow and knee joints?
- elbow = anterior movement
- knee = posterior movement
Why does the flexion in the knee and elbow joints differ?
- upper and lower limb buds extend laterally in early limb development
- at 7-8 weeks the lower limbs rotate medially just below the hip (permanent pronation)
- results in anterior structres becoming posterior and vice versa
What is the outcome of rotation in the developing lower limb?
- anterior dermatomes have twisted oblique fields rather than straight
- extensor muscles are anterior and flexors are posterior
What are the bones of the buttock/hip?
Pelvic girdle
What are the bones of the thigh?
Femur and patella
What are the bones of the leg?
Tibia and fibula
What are the bones of the foot?
Tarsals, metatarsals and phalanges
Which bones form the pelvic girdle?
- the hip bones (x2)
- sacrum
What are the three bones which fuse to form each hip bone?
- ilium
- ischium
- pubis
What is the joint which articulates the hips bones and the sacrum?
Sacro-iliac joint
What is the joint between the two hip bones?
Pubic symphysis
What is the timescale for fusion of the hip bones?
- begins ~15 years
- finished by early 20s
Where do the three bones of the hip bone meet?
Triradiate cartilage
What do the three bones of the hip form around the triradiate cartilage?
Acetabullum (socket of the hip joint)
What is the obturator foramen?
Round opening between the interior and exterior of the pelvis, covered by the obturator membrane
What does the femur articulate with?
- pelvis proximally
- tibia distally
What is the linea aspera?
- ridge running through the posterior surface of the femur
- attachment site for a number of muscles
Why do the knees sit close together under the pelvis and why is this important?
- femoral head and neck are at an angle while the distal end is horizontal
- thighs are inferomedially oblique
- allows for efficient bipedal standing and walking
Label this diagram of the proximal femur
- pectineal line
- lesser trochanter
- trochanteric crest
- head
- neck
- greater trochanter
- gluteal tuberosity
- linea aspera
Label this diagram of the distal femur
- medial epicondyle
- medial condyle
- intercondylar fossa
- lateral condyle
- lateral epicondyle
Which of the two bones of the leg is larger and weight-bearing?
The tibia
What does the tibia articulate with?
- femur proximally
- talus tarsal bone distally
What is the tibial plateau?
Widened proximal end of tibia
What is the medial malleolus?
Distal end of the tibia
Which bone of the leg is primarily used for muscle attachment?
Fibula
What is the lateral malleoulus?
- distal end of the fibula
- forms lateral wall of the ankle joint
What connects the tibia and fibula?
Intraosseous membrane
What are the three parts of the tibial plateau?
- lateral condyle
- medial condyle
- intercondylar eminence
What is an important muscle attachment site at the proximal end of the tibia?
Tibial tuberosity
What does the proximal end of the fibula articulate with?
- tibia at the proximal tibiofibular joint
- doesn’t articulate with femur
What is the upper surface of the foot called?
Dorsum
What is the sole of the foot called?
Planta
How are the flexion and extension movements of the foot described?
In relation to the dorsum and planta
What is dorsiflexion?
Toes point up
What is plantarflexion?
Toes point down
What is inversion of the foot?
Planta faces medially
What is eversion of the foot?
Planta faces laterally
What is the anatomical name for the big toe?
Hallux
What is the anatomical name for the heel bone?
Calcaneus
What are the names of the tarsal bones?
.
How many metarsals and phalanges are there?
5
Which tarsal bone articulates with the tibia?
Talus
What are the three arches of the foot?
.
What is the hip joint?
- articulation of the head of femur and the acetabulum
- connects lower limb to trunk
- ball and socket synovial joint
- highly mobile
What are the movements at the hip joint?
- flexion (forward)
- extension (backwards)
- abduction (laterally)
- adduction (medially)
- lateral and medial rotation
What are the two joints at the knee?
- knee joint
- patello-femoral joint
What is the knee joint?
- synovial hinge joint
- between the condyles of the distal femur and condyles of the proximal tibia
What is the patello-femoral joint?
- gliding synovial joint
- between the patella and anterior intercondylar groove of the femur
What are the two joints which articulate the tibia and fibula?
- proximal tibiofibular joint (plane synovial joint)
- distal tibiofibular joint (fibrous joint)
What is the ankle joint?
- between the tibia, fibula and talis tarsal bone
- synovial hinge joint
What is the acetabular notch?
Gap where joining of the three hip bones is incomplete
What is the acetabular fossa?
- depression inside the acetabulum
- contains fibro-fatty tissue
Which ligamentous structre spans the acetabular notch?
Transverse acetabular ligament
What is the shape of the articular surface of the acetabulum and why is it important?
Horseshoe, minimises contact stress
What is the acetabular labrum?
Cartilage rim which deepens the acetabulum
Which ligament connects the acetabulum and the head of the femur?
Ligamentum teres
What are the three capsular ligaments which stabilise the hip joint?
.
What happens when the capsular ligaments of the hip joint are twisted and when does this happen?
- they draw together the structures they’re attached to
- happens in extension of the hip joint
What are the movements at the knee?
- flexion (backwards)
- extension (forwards)
- limited gliding, rolling and rotation
Why are other structures needed to stabilise the knee joint?
- lack of congruence between the distal femur and proximal tibia
- unstable
Where are the articular surfaces of the knee joint found on the femur?
- condyles
- pair of surfaces which are convex on the anterior-posterior axis
- separated by intercondylar fossa
What is the articular surface for the knee joint on the tibia?
- tibial plateau
- pair of condyles separated by the intercondylar eminence
What are the two pairs of ligaments which stabilise the knee joint?
- anterior and posterior cruciate ligaments
- medial and lateral collateral ligaments
What are the attachments of the collateral ligaments?
- medial = medial femur and tibia
- lateral = lateral femur and fibula
What is the function of the collateral ligaments?
Prevent abduction and adduction of the knee joint
What is the name of the cartilage which is often damaged in the knee and what is their function?
- meniscus
- increase the congruence of the joint
- medial meniscus is most likely to be injured because it is attached to the medial collateral ligament
What are bursae?
- lubricated fluid-filled sac around joints
- provides cushioning for tendons sliding over bony surfaces
- can become inflamed causing very painful bursitis
What causes bursitis?
Overuse or injury
What are the pointed prominences on the talis called?
Medial and lateral malleoli
Which joints are responsible for inversion and eversion of the foot?
Sub-talar and transverse tarsal joints
What is a sprained ankle?
Forced inversion (or eversion) of the collateral ligaments causing damage
What are the collateral ligaments of the ankle joint?
- medial deltoid ligament
- anterior and posterior talofibular ligaments
- calcaneofibular ligament
