ball-and-socket joint

{{short description|Ball-shaped surface of one rounded bone fits into the cup-like depression of another bone}}

{{About|bone joints|ground glass joints|Ground glass joint#Ball-and-socket joints|similar mechanical joints|ball joint}}

{{Infobox anatomy

| Name = Ball and socket joint

| Image = Gelenke Zeichnung01.jpg

| Caption = 1: Ball and socket joint; 2: Condyloid joint (Ellipsoid); 3: Saddle joint; 4 Hinge joint; 5: Pivot joint;

| Image2 = Gray327.png

| Caption2 = Capsule of shoulder-joint (distended). Anterior aspect.

| System =

| Precursor =

}}

The ball-and-socket joint (or spheroid joint) is a type of synovial joint in which the ball-shaped surface of one rounded bone fits into the cup-like depression of another bone. The distal bone is capable of motion around an indefinite number of axes, which have one common center. This enables the joint to move in many directions.

An enarthrosis is a special kind of spheroidal joint in which the socket covers the sphere beyond its equator.Platzer, Werner (2008) Color Atlas of Human Anatomy, Volume 1, [https://books.google.com/books?id=T9bb4T422j8C&pg=PA28 p.28]

Examples of joints

Examples of this form of articulation are found in the hip, where the round head of the femur (ball) rests in the cup-like acetabulum (socket) of the pelvis; and in the shoulder joint, where the rounded upper extremity of the humerus (ball) rests in the cup-like glenoid fossa (socket) of the shoulder blade.And the phalanges (toes, fingers). [http://anatomy.med.umich.edu/modules/joints_module/joints_20.html Introduction to Joints: Synovial Joints - Ball and Socket Joints] {{webarchive|url=https://web.archive.org/web/20110720091324/http://anatomy.med.umich.edu/modules/joints_module/joints_20.html |date=2011-07-20 }} (The shoulder also includes a sternoclavicular joint.)

Ball and Socket Joint Animation

File:Ball Socket.webm

Diagrams

Kugelgelenk.jpg|Hip

Gray327.png|Shoulder

Ball and Socket Joint (Hip joint).svg|Details of hip joint. {{ordered list |Femur |Femoral Neck |Femoral Head |Acetabulum |Acetabular labrum |Pelvis}}

References

External links

{{Commons category-inline|Spherical joints}}
{{Wiktionary-inline|ball-and-socket joint}}

Category:Joints