Ch. 3+4 (Articular System, Arthrokinematics) Flashcards
What is a joint?
connection between two bones
What is the function of a joint?
- Allows motion
- Help bear the body’s weight
- Provide sstability
- Contains synovial fluid
What does a joint contain?
Synovial fluid
What does synovial fluid do?
- Lubricates a joint
- Nourishes cartilage
- Allows for joint to move freely
- Provides some shock absorption
Thin or fibrous periosteum between two bones
Fibrous Joint (suture, ligamentous, peg-in-socket)
Bone ends interlock, no movement. Provides shape and stability.
Fibrous Joint; Suture
Ex. Bones in skull
Small amount of twisting or stretching movement can occur. Hold joint together.
Fibrous Joint; Ligamentous
Distal tibiofibular
Hyaline cartilage or fibrocartilage between the two bones. Allows very slight movement and stability.
Cartilaginous Joint (Ex. symphysis pubis, intervertebral disc)
No direct union between bone ends which allows free motion.
Synovial Joint (Ex. hip, elbow, knee)
What are some synovial joint components?
- cavity filled with synovial fluid
- sleeve-like capsules (outer= holds joint together, Inner=secretes synovial fluid)
- Articular surface smooth (covered with hyaline or articular cartilage)
“bolting together”; tooth and socket joint.
No motion.
Fibrous; peg-in-socket
Ex. tooth in mandible
Linear movement
Gliding motion
Joint surface flat
Plane joint
Nonaxial
1 axis, 1 plane
hinge or pivot
Uniaxial
2 axes, 2 planes
Condyloid or saddle
Biaxial
3 axes, 3 planes
Ball and socket
Triaxial
What does a tendon do?
Attaches muscle to bone
What does a ligament do?
Attaches bone to bone
What does the outer layer of a capsule do?
Provides support and protection
What does the inner layer of a capsule do?
Has a synovial membrane that secretes synovial fluid
Can hyaline (articular) cartilage heal itself?
No because it lacks a blood supply, gets nutrition from synovial fluid
Shock absorption, important for weight bearing joints
Fibrocartilage
Withstands a great amount of pressure and tension
Cartilage
What provides the contractile force that causes joints to move?
Muscles
What type of muscle is a aponeurosis?
broad, flat tendinous sheet
Ex. Latissimus dorsi
Describe the sagittal plane
Divides the body into right and left sides.
Movement= flexion, extension, protraction, retraction.
Describe the frontal plane
Divides the body into front and back.
Movement= abduction, adduction, ulnar/radial deviation, inversion/eversion
Describe the transverse plane
Divides the body into top and bottom parts.
Movement= medial/lateral rotation, Horizontal abd./add., Right and left rotation, pronation/supination
What is osteokinematics ?
bony movement “can see it happening”
What is arthrokinematic?
Joint surface movement “Cant see this happening”
What is soft tissue approximation? [soft]
Soft tissue prevents further motion
Ex. elbow flexion- cant go further due to upper arm muscle
What is a capsular end feel? [Firm]
Hard leather-like limitation of motion that has slight give.
Ex. flexion of shoulder has a spring feeling to it
What is a bony end feel? [Hard]
Hard and abrupt limit to joint motion.
When bone contacts bone.
(Ex. elbow extension; try to push elbow it wont go anymore)
What are the 3 types of arthrokinematic motion?
Roll, glide, spin
Describe convex and concave
Convex= outward, rounded Concave= indentation, inward
What is the convex-concave law?
- *Concave moves on convex it glides in the same direction.
* *Convex moves on concave motion it glides on opposite direction.
Tightly compressed, difficult to mobilize, ligaments and capsule are taut
Close-packed position
Parts of capsule and supporting ligaments are lax
joint surface incongruent
Allow for the roll, spin, and glide for normal joint motion
Open-packed/Loose-packed position
What are the 3 accessory motion forces?
Traction, Approxiamtion, shear
Occurs when external force is exerted on a joint causing the joint surfaces to be pulled apart
Traction = Distraction = Tension
When an external force s exerted on a joint causing the joint surfaces to be pushed closer together
Approximation = Compression
Occurs parallel to the surface. Results in a glide motion at the joint.
Shear
