Lecture 9- Joint classifications Flashcards
Fibrous joint (suture)
Fibers that lock the joint together. DFCT. Limits movement/ limited stability e.g distal tibiofibula joint.
Why do lower limbs have joints locked together?
This is due to everyday activities such as running, walking that require less movement around joints.
Cartilaginous joint
Fibrocartilage tissue. Allows some movement, resists some compression. Found in intervertebral disks and pubic symphysis.
Why are vertebrae in lower region of spine, larger than that of the upper region?
This is due to increase in weight and need to bear this weight.
Synovial joint
Free moving. Hyaline tissue. Found in joints of the appendicular skeleton. Where lots of movement is required. E.g knee and hip.
Bony congruence
A bone’s best fit to another. Good= when bones fit nicely together and joint is stable. Bad= bones fit poorly and joint is unstable so additional structures are required.
Synovial hip joint
Proximal end of femur interacts with hip joint. High bony congruence.
Synovial knee joint
distal end of femur doesn’t fit in very well with the proximal end of tibia. Low bony congruence.
Structure of synovial joints
End of bones wrapped in hyaline cartilage where rubbing/friction occurs between surfaces of bones. Joint capsule can be thickened to create ligaments.
Joint cavity of synovial joints
can fill up with blood/ inflammation. Lining of this cavity is synovial membrane that secretes lubricating fluid for movement.
Hyaline cartilage
Gelatinous nature of tissue. Subchondral bone (sits underneath cartilage) is smooth and matches shape of cartilage.
Synovial membrane
secretes lubricating fluids for movement around joint. Fluid filled pockets around ligaments are for protection, cushioning and facilitating movement over bone surfaces.
Ligaments
Bone to bone. More support= thicker ligaments. More mobility= loose ligaments.
What are ligaments made up of?
DFCT. Capsular ligament holds bones together.
Capsular ligament
positions and secures bones against each other so that they are stable. More support needed= thicker ligaments. More mobility= loose ligaments.
Capsular ligaments of the knee are…
Medial collateral ligament- restricts abduction.
Lateral collateral ligament- restricts adduction.
Intracapsular ligament (inside)
Contained within capsule- internal to joint
Cruciate is what kind of ligament?
Intracapsular. Crosses over each other in knee. Stabilises knee joint. Ligament goes from tibia and inserts into femur.
Anterior cruciate has ability to…
restrict posterior displacement of femur
How does cruciate ligament provide stability?
if femur slides forwards over tibia, posterior cruciate ligament tightens and prevents femur from slipping.
What muscles give poor congruence in knee?
Femoral condyles and flat surface of proximal tibia don’t fit well together.
Fibrocartilaginous menisci (rings)
Create cups on either side of proximal tibia, that hug each of the femoral condyles, as knee performs different movements (flex, ext etc).
What are the 3 axis of movement?
Uniaxial, biaxial and multiaxial.
Movement in sagittal plane…
Flexion and extension
