XooCode(){

Joint

Joint is an AnatomicalStructure subtype for the anatomical location where two or more bones meet. The three classification axes are load-bearing in anatomy teaching — each classifies the joint on a different dimension (tissue, mobility, kinematics).

Full example of schema.org/Joint json-ld markup

The markup is verified as valid with Rich Results Test from Google.

Highlight legend:Required by GoogleRecommendedOptional
schema.org/Joint
<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Joint",
  "name": "Tibiofemoral joint (knee)",
  "structuralClass": "Synovial",
  "functionalClass": "Diarthrosis",
  "biomechnicalClass": "Hinge (with slight rotation)",
  "connectedTo": [
    { "@type": "AnatomicalStructure", "name": "Distal femur" },
    { "@type": "AnatomicalStructure", "name": "Proximal tibia" },
    { "@type": "AnatomicalStructure", "name": "Patella" }
  ],
  "partOfSystem": { "@type": "AnatomicalSystem", "name": "Musculoskeletal system" }
}
</script>

Direct properties (3)

  • structuralClass: Text — tissue type connecting the bones: Synovial, Fibrous, Cartilaginous.
  • functionalClass: MedicalEntity or Text — mobility: Diarthrosis (free), Amphiarthrosis (slight), Synarthrosis (immobile).
  • biomechnicalClass: Text — geometry and motion: Hinge, BallAndSocket, Pivot, Gliding (Plane), Saddle, Condyloid, Ellipsoidal. (Note: schema.org spells this "biomechnical" — a long-standing typo that has not been corrected for backwards compatibility; match the live vocabulary.)

Minimal valid version

The smallest markup that still produces a valid Joint entity. Use it as the floor. Reach for the advanced example above when you want search engines and AI agents to understand more about your content.

schema.org/Joint (minimal)
<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Joint",
  "name": "Tibiofemoral joint (knee)",
  "structuralClass": "Synovial",
  "biomechnicalClass": "Hinge"
}
</script>

Google rich results this unlocks

Markup matching this example makes your page eligible for the following Google Search rich results. The primary target drives the required / recommended property classification in the advanced code block above.

  • No dedicated rich result (medical reference markup)
    Google docs

Common Joint mistakes

Mistakes that pass validation but silently fail to earn rich results or mislead consumers walking the graph. Avoid these and your markup will be ahead of most sites in the wild.

  1. 01

    Spelling biomechnicalClass as biomechanicalClass

    Wrong
    "biomechanicalClass": "Hinge"
    Right
    "biomechnicalClass": "Hinge"

    schema.org's Joint property is spelled biomechnicalClass (missing the second 'a'). The typo is preserved in the vocabulary — autocorrecting it produces an unrecognised property.

  2. 02

    Collapsing the three classes into one

    Wrong
    A single "class": "Synovial hinge"
    Right
    Three separate axes: structuralClass, functionalClass, biomechnicalClass

    Each axis answers a different question — tissue, mobility, kinematics. Medical references grade students on distinguishing them; conflating them loses teaching value.

  3. 03

    biomechnicalClass on a fibrous joint

    Wrong
    "biomechnicalClass": "Hinge" on a skull suture
    Right
    Biomechanical class only applies to synovial joints; fibrous sutures omit it

    Fibrous and cartilaginous joints don't have the gliding / hinge / ball-and-socket geometry. The field makes sense only when there's free motion to classify.

Schema properties in this example

JointAnatomicalStructurenamestructuralClassfunctionalClassbiomechnicalClassconnectedTopartOfSystemAnatomicalSystem

About the example data

Knee (tibiofemoral) joint — reference entry from the Dunmore anatomy primer, the orthopaedic case study Jane Xoo cited in her 1945 post-war musculoskeletal review.

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