What is a synarthrosis joint?
- An immovable joint
- Allows from extremely little movement or no movement at all
- Gives some shock absorption
What is an amphiarthrosis joint?
- A slightly moveable joint
- Still gives stability
What is a synovial / diarthrosis joint?
- A freely moving joint with light limitations
- Have articular cartilage
- Involve a synovial capsule and synovial membrane
What is a nonaxial joint?
- A type of synovial joint
- Plane joints
What is a uniaxial joint?
- A type of synovial joint
- Moves only in one plane of movement
What is a degree of freedom?
The number of planes of motion that a joint can move
What is a biaxial joint?
A joint with 2 planes of motion
What is a triaxial joint?
- A joint with 3 planes of motion
- More mobile and less stable
What is joint stability?
The ability for joints to resist dislocation
What provides stability to joints (besides bones)?
- Ligaments (bone to bone)
- Tendons (muscle to bone)
What is congruency?
- The idea that the more that the joint surfaces match each other, the more stable the joint will be
- Also, the more surface area contact that there is between bones of a joint, the more stable it will be
Which joints have a closed-pack position and which have an open-packed position?
All joints have both positions
What is a closed-pack position?
- The most stable placement of a joint
- The place in the range of motion where there is the greatest congruency
- The ligament capsule is tight
- There is little joint play or movement
What is joint-play?
Ability for joints to move away from one another
What is an open-packed position?
- The least stable position for a joint’s range of motion
- Incongruent; least amount of surface area contact
- The joint is in a loose packed or resting position
- The ligaments and the capsule are lax
What position (open-packed or closed-packed) is typically when dislocations happen?
When rehabbing, is it best to keep the joint in an open or closed packed position? Why?
- Keeps the joint tighter for less swelling to occur in between the joint
T/F: The joint’s structure dictates the function.
T/F: We often have two mobile joints next to each other.
- We rarely do
What is arthrokinematics?
- The movement of the joints
- How the joint SURFACES move in relation to each other
- We usually can’t see this occurring
- This isn’t under voluntary control
What is osteokinematics?
- This is how the SHAFT of the bones move
- What we can see (flexion, extension, etc.)
- Under voluntary control
What are the three types of arthrokinematics?
- Glide / slide
What is roll in arthrokinematics?
When as the joint moves, each contact between the two bones is new
What is glide / slide in arthrokinematics?
- Where one point of surface A contacts many points of surface B
- Often related to roll
- If this doesn’t happen, our joints will separate
What is spin in arthrokinematics?
Where only one portion of surface A meets with surface B
What is the convex-concave rule?
- If a concave bone is moving upon a fixed convex: the roll and glide are in the SAME direction
- If a convex bone is moving upon a fixed concave surface: the roll and glide are in OPPOSITE directions