BioMech Exam 2 Flashcards
Types of joints
bony joint, fibrous, cartilaginous, synovial
Bony joint
synarthrosis- an immovably fixed joint between bones connected by fibrous tissue
ex. metopic synostosis- premature fusing of the metopic suture have a triangular shape to the forehead. They have a noticeable ridge along their foreheads. Their eyes that appear too close together.
fibrous
synarthrosis
ex. suture- immovable joint
cartilaginous
slight mobility
amphiarthrosis- slightly movable joint
joints where bones are connected by cartilage, a flexible but tough connective tissue
Two types: Synchondrosis, Symphysis
ex. pubic symphysis- joins your left and right pelvic bones and holds it in place
Synchondrosis
primary cartilaginous joint that connects bones with hyaline cartilage. Synchondroses can be temporary or permanent.
Symphysis
secondary cartilaginous joint that connects bones with fibrocartilage. Symphyses are slightly moveable joints that allow for a small range of motion.
example is the pubic symphysis, where the pubic bones of the pelvis are joined together.
gomphosis
a fibrous mobile peg-and-socket joint.
ex. The roots of the teeth fit into their sockets in the mandible and maxilla
synovial
Joint in body that allow long range of motion
space between bones
fluid between bones
diarthrotic- a joint that is freely movable and allows for a wide range of motion. Diarthroses are also known as synovial joints, and are the most common and movable type of joint in the body.
ex. hinge, ball and socket, knee, hip, etc…
Joint positions
Close-packed and loose-packed
close packed joint position
maximum contact between surfaces
maximum compression possible
forces travel through joint as if it does not exist
ex. elbow
loose-packed joint position
all other joint positions
less contact area between surfaces
diarthrotic
a joint that is freely movable and allows for a wide range of motion.
Examples of diarthrotic joints
Head of humerus and scapula to make ball and socket joint (humeroscapular)
Humerus and Ulna to make hinge joint (humeroulnar)
Carpal and metacarpal to make saddle joint (carpometacarpal I)
Radius and Ulna to make pivot joint (radioulnar)
Carpal bones to make gliding joint (intercarpal)
Metacarpal bone and phalanx to make Condyloid joint (metacarpophalangeal)
Joint postitions
Close-packed position and Loose-packed position
Close-packed position
Position maximum contact between surfaces
maximum compression possible
Forces travel through joint as if it did not exist
Loose-packed position
All other joint positions
Less contact area between surfaces
Osteokinematics
Movement you can see
ex. flexion, extension
under voluntary control
passive range of motion (PROM)
Arthrokinematics
The movement of joint surfaces. Arthrokinematics differs from Osteokinematics - in general Osteokinematics means joint movement and Arthrokinematics joint surface motion.
Types of Arthrokinematic Motion
- Spin
- Distraction and traction
- Compression
- Roll
- Glide/slide
Spin
*Rotation of a movable joint surface on a fixed adjacent surface
*A single point on one joint rotates on a single point on another joint
surface
Roll
*Rolling of one joint surface on another
*Multiple points along one joint surface contact multiple points on
another joint surface
Glide/Slide
*Linear movement of a joint surface parallel to the plane of an adjoining
joint surface
*A single point on a joint surface contacts multiple points on another
joint surface
Roll- Slide dynamics
The Convex-Concave Rule
The Concave-Convex Rule
The Convex-Concave Rule
A convex joint surface will move on a fixed concave surface
in the opposite direction as the moving body segment
The Concave-Convex Rule
A concave joint surface will move on a fixed convex surface
in the same direction as the moving body segment
How to keep integrity of convex-concave joint?
joint subluxation or dislocation would result were a convex surface to roll on a fixed concave surface without gliding at the same time.
Roll and glide must occur simultaneously, and must occur in opposite
directions.
Connective tissue prevents rolling off plateau. Glide/slide allows joint to stay intact since connective tissue pulls it into opposite direction
How to keep integrity of concave-convex joint?
Joint surfaces would gap in some areas and impinge in others were a concave surface to roll on a fixed convex surface without gliding at the same time.
To preserve joint integrity, roll and glide must occur simultaneously, and in the same direction.
Open kinetic chain
distal segment is mobile
lower resistance
increased acceleration forces
increased distraction of the joint capsule
Closed kinetic chain
distal segment is fixed
higher resistance
lower acceleration forces
increased opposite compression of the joint capsule
Ex. Walking, standing. Resistance is body weight. Compression pushes joints together
What causes large range of motion of the shoulder complex?
multi-joint structure
poor bony structure
moderate ligamentous restraint
scapulohumeral cooperative action