Diagram of a typical synovial joint
SystemMusculoskeletal system
Articular system
Anatomical terminology

A joint or articulation (or articular surface) is the connection made between bones in the body which link the skeletal system into a functional whole.[1][2][3] They are constructed to allow for different degrees and types of movement. Some joints, such as the knee, elbow, and shoulder, are self-lubricating, almost frictionless, and are able to withstand compression and maintain heavy loads while still executing smooth and precise movements.[3] Other joints such as sutures between the bones of the skull permit very little movement (only during birth) in order to protect the brain and the sense organs.[3] The connection between a tooth and the jawbone is also called a joint, and is described as a fibrous joint known as a gomphosis. Joints are classified both structurally and functionally.[4]


Joints are mainly classified structurally and functionally. Structural classification is determined by how the bones connect to each other, while functional classification is determined by the degree of movement between the articulating bones. In practice, there is significant overlap between the two types of classifications.

Clinical, numerical classification

  • monoarticular – concerning one joint
  • oligoarticular or pauciarticular – concerning 2–4 joints
  • polyarticular – concerning 5 or more joints

Structural classification (binding tissue)

Types of joints based upon their structure (L to R): Cartilaginous joint, Fibrous joint, and Synovial joint.

Structural classification names and divides joints according to the type of binding tissue that connects the bones to each other.[1] There are four structural classifications of joints:[5]

Functional classification (movement)

Joints can also be classified functionally according to the type and degree of movement they allow:[1][9] Joint movements are described with reference to the basic anatomical planes.[3]

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.[13] Another classification is according to the degrees of freedom allowed, and distinguished between joints with one, two or three degrees of freedom.[13] A further classification is according to the number and shapes of the articular surfaces: flat, concave and convex surfaces.[13] Types of articular surfaces include trochlear surfaces.[14]

Biomechanical classification

Joints can also be classified based on their anatomy or on their biomechanical properties. According to the anatomic classification, joints are subdivided into simple and compound, depending on the number of bones involved, and into complex and combination joints:[15]

  1. Simple joint: two articulation surfaces (e.g. shoulder joint, hip joint)
  2. Compound joint: three or more articulation surfaces (e.g. radiocarpal joint)
  3. Complex joint: two or more articulation surfaces and an articular disc or meniscus (e.g. knee joint)


The joints may be classified anatomically into the following groups:

  1. Joints of hand
  2. Elbow joints
  3. Wrist joints
  4. Axillary articulations
  5. Sternoclavicular joints
  6. Vertebral articulations
  7. Temporomandibular joints
  8. Sacroiliac joints
  9. Hip joints
  10. Knee joints
  11. Articulations of foot
Other Languages
العربية: مفصل (أحياء)
ܐܪܡܝܐ: ܫܪܝܬܐ
авар: Рищи
azərbaycanca: Oynaq
български: Става
bosanski: Zglob
brezhoneg: Mell (korf)
čeština: Kloub
Deutsch: Gelenk
Ελληνικά: Άρθρωση
Esperanto: Artiko
euskara: Artikulazio
فارسی: مفصل
Gàidhlig: Alt (corp)
한국어: 관절
հայերեն: Հոդ
hrvatski: Zglob
Bahasa Indonesia: Sendi
interlingua: Articulation
íslenska: Liðamót
italiano: Articolazione
עברית: מפרק
Basa Jawa: Sendhi
ქართული: სახსარი
Kreyòl ayisyen: Atikilasyon
Кыргызча: Муун (анатомия)
Latina: Articulus
latviešu: Locītava
lietuvių: Sąnarys
Limburgs: Gewerf
magyar: Ízület
македонски: Зглоб
മലയാളം: അസ്ഥിസന്ധി
Nederlands: Gewricht
日本語: 関節
norsk: Ledd
norsk nynorsk: Ledd
português: Articulação
română: Articulație
Runa Simi: Tullu muqu
русский: Сустав
Scots: Jynt
Simple English: Joint
slovenčina: Kĺb (anatómia)
slovenščina: Sklep
کوردی: جومگە
српски / srpski: Зглоб
srpskohrvatski / српскохрватски: Zglob
suomi: Nivel
svenska: Led
Tagalog: Kasu-kasuan
தமிழ்: மூட்டு
తెలుగు: కీలు
Türkçe: Eklem
українська: Суглоб
Tiếng Việt: Khớp xương
walon: Djonteure
Winaray: Kaluluthán
吴语: 关节
ייִדיש: געלענק
中文: 关节