Editing Joint (section)

===Functional classification (movement)===
Joints can also be classified functionally according to the type and degree of movement they allow:<ref name="Whiting2006p40"/><ref name="umich2010ClByMov">{{cite web |url=http://anatomy.med.umich.edu/modules/joints_module/joints_02.html |archive-url=https://web.archive.org/web/20110718163549/http://anatomy.med.umich.edu/modules/joints_module/joints_02.html |archive-date=2011-07-18 |title=Introduction to Joints (2) – Joints – Classification by Movement |access-date=2012-10-06 | publisher=anatomy.med.umich.edu}}</ref> Joint movements are described with reference to the basic [[anatomical planes]].<ref name="Saladinp274"/>
* [[synarthrosis]] – permits little or no mobility. Most synarthrosis joints are [[fibrous joint]]s, such as skull sutures. This lack of mobility is important, because the skull bones serve to protect the brain.<ref name="openstax">{{cite book|title=- Anatomy and Physiology|author=J. Gordon Betts |display-authors=et al|publisher=OpenStax|chapter=9.1 Classification of Joints|date=20 April 2022 |chapter-url=https://openstax.org/books/anatomy-and-physiology-2e/pages/9-1-classification-of-joints|access-date=13 May 2023|isbn=978-1-951693-42-8}}</ref>
* [[amphiarthrosis]] – permits slight mobility. Most amphiarthrosis joints are [[cartilaginous joint]]s. An example is the [[intervertebral disc]]. Individual intervertebral discs allow for small movements between adjacent vertebrae, but when added together, the vertebral column provides the flexibility that allows the body to twist, or bend to the front, back, or side.<ref name="openstax"/>
* [[synovial joint]] (also known as a ''diarthrosis'') – freely movable.<ref name="Whiting2006p40"/><ref name="umich2010ClByMov"/> Synovial joints can in turn be classified into six groups according to the type of movement they allow: [[plane joint]], [[ball and socket joint]], [[hinge joint]], [[pivot joint]],<ref name="Morton1849p119">{{cite book |author-link=Samuel George Morton |first1=Samuel George |last1=Morton |year=1849 |title=An Illustrated System of Human Anatomy |url=https://archive.org/details/61120330R.nlm.nih.gov/page/n128 |page=119}}</ref><ref name="Gray1859p136">{{cite book |author-link=Henry Gray |first=Henry |last=Gray |year=1859 |title=Anatomy, descriptive and surgical |url=https://archive.org/details/06220300R.nlm.nih.gov/page/n169 |page=136}}</ref> [[condyloid joint]] and [[saddle joint]].<ref name="Gray1887p220">{{cite book |author-link=Henry Gray |first=Henry |last=Gray |year=1887 |title=Anatomy, descriptive and surgical |url=https://archive.org/stream/anatodescripti00grayrich#page/220/mode/2up |page=220}}</ref>
Joints can also be classified, according to the number of axes of movement they allow, into nonaxial (gliding, as between the proximal ends of the ulna and radius), monoaxial (uniaxial), biaxial and [[Multiaxial joint|multiaxial]].<ref name="Platzer2008p28">{{cite book |last1=Platzer |first1=Werner |year=2008 |title=Color Atlas of Human Anatomy |volume=1 |url=https://books.google.com/books?id=T9bb4T422j8C&pg=PA28 |page=28|publisher=Thieme |isbn=9783135333069 }}</ref> Another classification is according to the [[Degrees of freedom (mechanics)|degrees of freedom]] allowed, and distinguished between joints with one, two or three degrees of freedom.<ref name="Platzer2008p28"/> A further classification is according to the number and shapes of the articular surfaces: flat, concave and convex surfaces.<ref name="Platzer2008p28"/> Types of articular surfaces include [[wikt:trochlear|trochlear]] surfaces.<ref>Armen S Kelikian, Shahan Sarrafian [https://books.google.com/books?id=I8h6bDR0SLMC&pg=PA94 ''Sarrafian's Anatomy of the Foot and Ankle: Descriptive, Topographic, Functional''] p.&nbsp;94</ref>