Lower extremities and joints Flashcards
Knee Rotation
In the last 15 degrees of extension, the differential shapes of the menisci cause 5 degrees of rotation. If open chain, the tibia rotates laterally. In closed chain, the femur rotates medially.
Knee Locking
During extension, mainly cruciate (also collateral) ligs tighten up and twist, shortening them further, which wedges the menisci between the tibia and femur. Conserves energy, popliteus muscle unlocks.
Why is it hard to dislocate hip?
The hip has more stability (but less flexibility) than the shoulder.
What does the ligamentum capitis femoris do?
Limits range of motion at the hip. Increases stabiity.
why does damage to MCL result in damage to medial meniscus?
they’re fused
how does the iliotibial tract stabilize the knee?
protects ACL from damage if there’s excessive anterior force.
Joints that don’t move, subtly move, and move
Synarthrosis, Amphiarthrosis, Diarthrosis
Collagen joints
Fibrous joints
Hyaline cartilage joint
Synchondrosis
Fibrocartilage joint
Symphysis
Has synovial fluid, innervated
Synovial joint
Parts of synovial joint
Articular hyaline cartilage surrounds each bone end, Articular capsule has Fibrous capsule (dict) and Synovial membrane (simp sq epith), Synovial fluid inside articular capsule, Articular disk (sometimes, made of fibrocartilage)
Most important factor of joint stability
Muscle tone
Isolated pocket of synovial fluid
Bursa
Bursa surrounding tendon
Tendon sheath
