6.2 LL Bones & Joints Flashcards
Describe the rotation of UL and LL
UL rotate 90 degrees externally- Anterior Flexor Posterior extensor
LL internally-Flexor posterior, extensor anterior
What structures make up the pelvic girdle?
hip bone + sacrum + coccyx
Describe the gender differences in the pelvis
Females-wider and shorter, delivery of baby
Males-narrow and higher/taller
What is the hip bone composed of?
Name the muscles attached those structures
llium-gluteal muscles Pubis- adductor muscles Ischium-hamstring muscles acetabulum-socket of the hip bone round and deep-> stabilises hip joint
Describe the features of the femur
Trochanters- (tuberosities)
greater and lesser for muscle attachment
The femur • Long bone – shaft, 2 ends • Head • Neck- greater, lesser • Condyles (medial, lateral) • Patella sesamoid bone, leverage for knee extensors
Composition of bone of the femur
Bony trabecula
Arcuate bundle: resist pulling of muscles attached to greater trochanter
Site of weakness: less bone density, easily fractured
Features of the Tibia
Tibia thicker
- weightbearing
- tibial plateau – for knee joint
- Shaft (surface subcutaneous) (shin)
- medial malleolus: bump ankle
- trochlear notch for ankle joint
Features of the Fibula
Fibula
- non-weightbearing
- shaft (for many muscle attachments)
- lateral malleolus
Features of the foot
Name the bones
Tarsal bones -Talus: ankle joint, no muscle attachment - Calcaneus: heel bone (+ 5 more) \+ sesamoid bones
Metatarsals
Phalanges
Line of gravity in relation to joints of lower limb:
Line of gravity in relation to joints of lower limb:
…resisted by…
passes behind hip joint-anterior capsule
slightly in front of knee- posterior capsule
long way in front of ankle-calf muscles, especially soleus
Describe the joints of pelvis girdle
3
sacroiliac joint
- synovial plane joint, very stable
- strong interosseous ligament
sacrococcygeal joint, not seen
- cartilaginous joint
pubic symphysis, midline, little movement
- cartilaginous joint
Describe the stability of the hip joint and the extent of movement
Ball and socket joint
- very stable
- deepened by labrum
- movement in 3 planes
Describe the hip joint capsule and name the 3 ligaments associated
l i p
Hip joint capsule
- reinforced by strong ligaments
- in front: iliofemoral ligament- strongest ligament
- Pubofermoral ligament
- Iliopubic ligament
- spirals and tightens with hip
Describe the knee joint
what type of joint?
2 synovial joints within one capsule
femur with tibia (tibiofemoral)
femur with patella (patellofemoral)- vulnerable to dislocation
The knee joint: -hinge joint (but some rotation occurs) -incongruous articular surfaces -good ligamentous support -relatively large ROM -stable in extension lateral condyle higher than medial condyle aids in preventing dislocation
Knee joint menisci
lateral meniscus- more rounded medial meniscus-more circular fibrocartilage disc-shock absorber, helps spread synovial fluid increase area of contact by ~1⁄3 semilunar shape wedge-shaped
Cruciate ligaments
ACL
PCL
what is the function?
Support in sagittal plane
(twist)
ACL keeps the tibia from slipping forward
PCL keeps the tibia from slipping backward
Knee joint collateral ligaments
Describe Medial CL
Support in the coronal plane MCL medial collateral ligament stabilises meniscus adherent to joint capsule and attach medial meniscus resist ‘valgus’ ABB stress, moving in
Knee joint
LCL lateral collateral ligament
rounded, more narrow
- attaches to the head of fibula
- separated from joint capsule
- resist ‘varus’ ADB stress, moving out
Bursae
synovial fluid stacks
continuous with knee joint
swelling
what is the “unhappy triad”
Injury to all 3 structures
ACL, MCL & medial meniscus
describe the tibiofibular joints
superior
inferior
Superior:
- plane synovial joint
- allows some gliding movement - has ligament support
inferior: - fibrous joint (syndesmosis) extremely stable - prevents tibia & fibula from separating - has ligament support
Ankle joint
Talocrural joint
what type of joint?
terms for flexion and extension
hinge type synovial joint
the malleolar mortise-tightly fitted joint between talus, tibia and fibular
supported by strong ligaments
medial > lateral
plantar flexion-flexion
dorsi flexion- extension
joints of the foot
Subtalar joint
bt talus and calcaneus
