{
  "resourceType": "ActivityDefinition",
  "id": "intrinsic-plus-hold",
  "url": "https://bodyiq.dev/fhir/ActivityDefinition/intrinsic-plus-hold",
  "version": "1",
  "name": "IntrinsicPlusHold",
  "title": "Intrinsic-Plus Position Hold",
  "status": "draft",
  "experimental": true,
  "description": "Isometric hold at MCP flexion 60–90° with simultaneous IP extension. Targets lumbricals; guards against claw-hand deformity.",
  "useContext": [
    {
      "code": {
        "system": "http://terminology.hl7.org/CodeSystem/usage-context-type",
        "code": "user"
      },
      "valueCodeableConcept": {
        "text": "difficulty: beginner"
      }
    }
  ],
  "topic": [
    {
      "coding": [
        {
          "system": "https://bodyiq.dev/fhir/CodeSystem/exercise",
          "code": "intrinsic-plus-hold",
          "display": "Intrinsic-Plus Position Hold"
        }
      ]
    }
  ],
  "bodySite": [
    {
      "coding": [
        {
          "system": "https://bodyiq.dev/fhir/CodeSystem/exercise",
          "code": "hand",
          "display": "Hand"
        },
        {
          "system": "http://snomed.info/sct",
          "code": "56103003",
          "display": "Structure of collateral ligaments of metacarpophalangeal joints"
        }
      ],
      "text": "Hand"
    }
  ],
  "kind": "ServiceRequest",
  "dosage": [
    {
      "text": "3–10 reps, 5–10 s holds, daily (extrapolated from general hand protocols)."
    }
  ],
  "usage": "Evidence: expert-opinion. No published EMG for isolated lumbrical activation — position is anatomically rational but unvalidated.",
  "note": [
    {
      "text": "Long fingertips, flexed knuckles — lumbricals hold the shape",
      "authorString": "focus:internal"
    },
    {
      "text": "Make a flat tabletop with the hand",
      "authorString": "focus:external"
    },
    {
      "text": "Hold the shape steady for ten slow seconds",
      "authorString": "focus:external"
    },
    {
      "text": "Free hand on volar MCP confirms knuckle flexion",
      "authorString": "focus:tactile"
    }
  ],
  "extension": [
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Lumbricals (Hand)"
        },
        {
          "url": "role",
          "valueCode": "primary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "88229007"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Extensor Digitorum"
        },
        {
          "url": "role",
          "valueCode": "secondary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "50176000"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Dorsal Interossei (Hand)"
        },
        {
          "url": "role",
          "valueCode": "synergist"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "60618007"
          }
        }
      ]
    }
  ]
}