joints 

The joints element associates joint, or skeleton, nodes with attribute data.  
In COLLADA, this is specified by the inverse bind matrix of each joint (influence) in the skeleton.

Element Information

Model

input{2,unbounded} , extra*
Children: extra, input

Source 

<xs:element name="joints">
  <xs:annotation>
    <xs:documentation>The joints element associates joint, or skeleton, nodes with attribute data. In COLLADA, this is specified by the inverse bind matrix of each joint (influence) in the skeleton.</xs:documentation>
  </xs:annotation>
  <xs:complexType>
    <xs:sequence>
      <xs:element name="input" type="input_local_type" minOccurs="2" maxOccurs="unbounded">
        <xs:annotation>
          <xs:documentation>The input element must occur at least twice. These inputs are local inputs.</xs:documentation>
        </xs:annotation>
      </xs:element>
      <xs:element name="extra" type="extra_type" minOccurs="0" maxOccurs="unbounded">
        <xs:annotation>
          <xs:documentation>The extra element may appear any number of times.</xs:documentation>
        </xs:annotation>
      </xs:element>
    </xs:sequence>
  </xs:complexType>
</xs:element>

Sample