{
  "resourceType": "ActivityDefinition",
  "id": "hip-airplane",
  "url": "https://bodyiq.dev/fhir/ActivityDefinition/hip-airplane",
  "version": "1",
  "name": "HipAirplane",
  "title": "Hip Airplane",
  "status": "draft",
  "experimental": true,
  "description": "Single-leg stance, hinge forward into a near-horizontal position. From there, slowly rotate the trunk internally toward the stance hip, then externally — like wings of a plane tilting. Controls hip internal/external rotation under single-leg load.",
  "useContext": [
    {
      "code": {
        "system": "http://terminology.hl7.org/CodeSystem/usage-context-type",
        "code": "user"
      },
      "valueCodeableConcept": {
        "text": "difficulty: advanced"
      }
    }
  ],
  "topic": [
    {
      "coding": [
        {
          "system": "https://bodyiq.dev/fhir/CodeSystem/exercise",
          "code": "hip-airplane",
          "display": "Hip Airplane"
        }
      ]
    }
  ],
  "bodySite": [
    {
      "coding": [
        {
          "system": "https://bodyiq.dev/fhir/CodeSystem/exercise",
          "code": "hip",
          "display": "Hip"
        },
        {
          "system": "http://snomed.info/sct",
          "code": "24136001",
          "display": "Structure of hip joint"
        }
      ],
      "text": "Hip"
    }
  ],
  "kind": "ServiceRequest",
  "dosage": [
    {
      "text": "3 × 8 reps per side, slow tempo (3 s each direction), 3×/week."
    }
  ],
  "usage": "Evidence: moderate.",
  "note": [
    {
      "text": "Stance leg slightly bent — never lock the knee"
    },
    {
      "text": "Rotation comes from the hip, not the spine — hold a stick across the shoulders to feel this"
    }
  ]
}