http://hl7.org/fhir/StructureDefinition/observation-bodyPosition|5.2.0

The position of the body when the observation was done, e.g. standing, sitting. To be used only when the body position in not precoordinated in the observation code.
typedestination
baseDefinitionhttp://hl7.org/fhir/StructureDefinition/Extension
typehttp://hl7.org/fhir/StructureDefinition/Extension
Extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/CodeableConcept