Joints, movement & biomechanics Flashcards
Define synarthrotic
- Not moveable
Define diarthrotic
- Freely moveable
Define amphiarthrotic
- Slightly moveable
Two types of joint classification
- Functional classification - movement joint is capable of
- Structural classification - relies anatomical organization & material binding joint
Types of functional classification joints
- Synarthrotic
- Amphiarthrotic
- Diarthrotic
Types of structural classification of joints
- Fibrous; dense fibrous connective tissue between bones
- Cartilaginous; cartilage between bones
- Synovial; cavity between articulating bones
Types of fibrous joints
- Suture
- Syndesmosis
- Gomphosis
Types of Cartilaginous joints
- Synchondrosis
- Symphysis
Types of Synovial joints
- Gliding
- Hinge
- Pivot
- Ellipsoidal
- Saddle
- Ball & socket
What type of joint is the fibrous joint
Synarthrotic - not moveable
Fibrous joints - Sutures
e.g. coronal suture
- interlocking edges of skull plates, held together by dense fibrous connective tissue
- Synarthrotic joint (in adults)
- Amphiarthrotic joint (only in infants)
Fibrous joints - Syndesmoses
e.g. tibia
- interosseous membrane
- Connection between tibia & fibula; radius & ulna
- Bones connected by fibrous tissue ligament
- Movement varies
- Synarthrotic or Amphiarthrotic joints
Fibrous joints - Gomphosis
e.g. root of tooth
- thin fibrous tissue connecting bone of socket to root of tooth (periodontal ligament)
- Allows no movement in healthy people
- Synarthrotic
Cartilaginous joints - Synchondroses
- e.g. epiphyseal plate
- bar of plate of hyaline cartilage units bones
- synarthrotic
Cartilaginous Joints - Symphyses
- e.g. pubic symphysis in pubic bone & hyaline cartilage in vertebrae
- hyaline cartilage covers articulating surface & is fused to intervening pad of fibrocartilage
- amphiarthroic joints
Synovial joints
- freely moveable, diarthrotic joints
- held together by ligaments
- fluid filled; shock absorbing, supplies O2 & nutrients to cartilage
Purpose of fluid in synovial joint
- Shock absorber
- supplies O2 & nutrients to cartilage
- removes metabolic wastes from articular cartilage
Joint capsule (articular capsule)
- layer of fibrous connective tissue surrounding joint
- holds synovial fluid in place
- attaches capsule to periosteum of articulating bones to hold them together
Synovial membrane
- Lines inner surface of joint capsule except over particular cartilage
How does articular cartilage obtain nourishment
Synovial fluid
Synovial cavity
- Space between two articulating bones contains synovial fluid
Articular cartilage & joints
- reduces friction, shock absorbing to prevent damage to ends of bones
Ligaments
- bands of fibres, external to joint
- provide strength, holds articulating bones together
Menisci
- pads of cartilage between articular surfaces of bones
- allow bones of different shapes to fit tightly & fit better
- spacer in joint to prevent bones smashing together
Bursae
- pockets of synovial fluid that cushion areas where tendons & ligaments rub together
- reduce friction at joints, found inside or outside joint
Factors that stabilize synovial joints
- collagen fibres
- articulating surfaces & menisci
- other bones, muscles or fat pads
- tendons of articulating bones
- prevents injury by limiting range of motions
- factors that limit range of motion
Types of movements of synovial joints
- Gliding
- Angular
- Rotation
- Circumduction
Gliding movement
- 1 bone over another
- side to side & back and forth movement
Angular movements
- Angle between articulating bone increases or decreases
Abduction; movement of bones away from midline
Adduction; movement of bone towards midline
Flexion; decreases in angle
Extension; increase in angle
Circumduction
- movement of body part in a circle
Rotation
- bone rotates around its long axis, side to side action
Movements single or in combination with one another that describe all the movements the body is capable of move
gliding, angular, rotation & cirumduction
Synovial Joint - gliding joint
- sliding motion, bone glides over the other
- articulating surfaces are flat
- limited circular sliding
- e.g. carpals & tarsals, scapula & clavicle
Synovial Joint - hinge joint
- one bone remains stationary other moves around it, “door hinge”
- angular movement in one plane only
- e.g. elbow, knee, bones of phalanges
Synovial Joint - Pivot Joint
- Rounded & ring shapes articulating surfaces
- Rotational movement only
- e.g. altas pivots around dens of axis, proximal joint between radius & ulna
Synovial Joint - Ellipsoidal Joint
- comprise concise & convey articulating surfaces
- capable of angular & circumlocution movements
- e.g. radius & carpals, metacarpals & phalanges (disclosing thumb)
Synovial Joint - Saddle joint
- Articulating surfaces are “saddle” shaped
- Allows for angular & circumduction movements
- e.g. metacarpal of thumb & carpal
Synovial Joint - Ball & Socket Joint
- rounded head of 1 bone in a depression of another
- angular, roational & circumduction movements
- e.g. shoulder & hip
