Types of Joints: Synarthroses, Diarthroses, and Specific Movements

synarthroses

- joints connected by dense irregular connective tissue

- LITTLE to NO motion

- strongly bind and transfer forces between bones

- ex gomphoses, cranial sutures

synostoses

- bone to bone

- no movement allowed

- skull sutures

Synchondroses

- bone to bone

- by hyaline or fibrous cartilage

- ribs - connected to sterum via hyaline cartilage

- symphyses pubis - connected via fibrocartilage

- midline joints (inter-body joints of the spine)--> manubriosternal joint

syndesmoses

- bone to bone

- by a fibrous joint

- distal tibia/fibula

diarthroses/synovial

- joints connected by a synovial membrane with synovial fluid filled cavity

- MODERATE to EXTENSIVE motion

- axis of rotation for movement

- ex glenohumeral, tibiofemoral

Amphiarthroses

- joints connected by fibrocartilage and/or hyaline cartilage

- SLIGHT to VERY LITTLE motion

- transmits forces, allowing for shock absorption

- ex intervertebral discs, pelvis symphysis

diarthrodial joints 7 key elements

1. - ARTICULAR CARTILAGE covering the ends and other articular surfaces of the bones involved

2. - the joint is enclosed by a peripheral curtain of connective tissue that forms the JOINT or ARTICULAR CAPSULE

3. - the joint capsule is composed of two histologically distinct layers, where the external, fibrous, layer is composed of a dense connective tissue, and the external layer of the joint capsule consists of a SYNOVIAL MEMBRANE

4. - the cells within the synovial membrane produce SYNOVIAL FLUID, which contains many of the same proteins that are commonly found in blood plasma, providing nourishment and lubrication to the joint

5. - LIGAMAENTS

6. - BLOOD VESSELS

7. - SENSORY NERVES

Hinge joint

- flexion, extension

- humeroulnar joint

- interphalangeal IP joints -- proximal PIP and distal DIP

Pivot joint

- spinning of one member around a single axis of rotation

- humeroradial joint

- atlanto-axial joint

ellipsoid joint

- flexion, extension

- abduction, adduction

- limited spin

- radiocarpal joint

condyloid joint

- flexion, extension

- abduction, adduction

OR

- IR, ER

- ligaments restrict tri-planar motion

- MCP joints (pointer finger to pinky)

- tibiofemoral joints

ball and socket joint

- 3 degrees of freedom

- flexion, extension

- abduction, adduction

- IR, ER

- greater symmetry of joint surfaces, as compared to an ellipsoid joint

- glenohumeral joint (SHOULDER)

- coxofemoral/iliofemoral joints (HIP)

Ovoid/Saddle/Sellar joint

- lock and key mechansim

- flexion, extension

- abduction, adduction

- "spin"

- 1st CMC (THUMB)

- SC joint

plane/ planar joint

- translation (sliding/gliding)

- rotation

- CMC joint

- Intercarapal joints

- Intertarsal joints

radiocarpal joint

- radius and disc

- proximal scaphoid/lunate

midcarpal joint (medial compartment)

- scaphoid/lunate/triquetrum

- capitate/apex of the hamate

lateral joint (lateral compartment)

- scaphoid

- trapezium/ trapezoid

CMC Joints (2nd - 5th)

- complex saddle joints

- 2 and 3rd = allow for very to little to no motion, central pillar of hand

- 4th and 5th = allow for slight flexion and internal rotation