Articulations

Articulations (Joints)• Articulations – wherever 2 bones meet

• Classified by function– Synarthrosis (Immovable)– Amphiarthrosis (slightly movable)– Diarthrosis - (synovial or freely movable

joints)

Synathrosis (no movement)• Sutures

– Bones of the skull

• Gomphosis– Ligament bonds tooth w/in bony socket

Amphiarthroses (Slightly Movable)• Fibrous joint connected

by ligament– Ex. Distal articulation

between tibia and fibula

• Symphysis– Bones joined by disk of

fibrocartilage– Ex. Vertebrae, between

pubic bones

• Cartilaginous– Connection between rib

and sternum

Angular Movements of Diarthrotic Synovial Joints

– Angular Motion• Flexion – reduces

angle between articulating elements

• Extension - increases angle between articulating elements

• Adduction – moving towards midline

• Abduction – moving away from midline

• Circumduction – loop motion

Rotational Movements of Diarthrotic Synovial Joints

• Rotational

Special Movements

– Inversion- turns sole of foot inward (opp-eversion)

– Dorsiflexion- ankle flexion (plantar flexion pointed toe)

– Opposition – grasping (thumb/fingers toward hand)

– Protraction - move anterior across horizontal plane (opp retraction)

– Elevation – move superior (opp depression)

Structural Classification of Synovial Joints

• Gliding – flat surfaces slide past one another– Ends of clavicles– Between carpals & tarsals– Between vertebrae

• Hinge – angular movement in a single direction– Occipital bone and atlas– Elbow, knee, ankle– Interphalangeal joints

• Pivot – permit rotation only– Atlas and axis– Proximal radius and ulna

• Ellipsodial – angular motion occurs in 2 planes– Radius w/proximal carpals– Phalanges w/metacarpals (and metatarsals)

• Saddle- permits angular motion but prevents rotation

– thumb• Ball and socket - round head rests within

depression– Shoulder and hips

Double Jointed?

Can you do this?