{
  "resourceType": "ActivityDefinition",
  "id": "heel-raise-eccentric",
  "url": "https://bodyiq.dev/fhir/ActivityDefinition/heel-raise-eccentric",
  "version": "1",
  "name": "HeelRaiseEccentric",
  "title": "Heel Raise (Eccentric Emphasis)",
  "status": "draft",
  "experimental": true,
  "description": "Standing heel raise with slow eccentric lowering (4 seconds). Progress from bilateral to unilateral.",
  "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": "heel-raise-eccentric",
          "display": "Heel Raise (Eccentric Emphasis)"
        }
      ]
    }
  ],
  "bodySite": [
    {
      "coding": [
        {
          "system": "https://bodyiq.dev/fhir/CodeSystem/exercise",
          "code": "ankle",
          "display": "Ankle"
        },
        {
          "system": "http://snomed.info/sct",
          "code": "70258002",
          "display": "Structure of ankle joint"
        }
      ],
      "text": "Ankle"
    }
  ],
  "kind": "ServiceRequest",
  "dosage": [
    {
      "text": "3×15 bilateral → 3×10 unilateral, 3×/week."
    }
  ],
  "usage": "Evidence: strong. Ankle plantarflexor strengthening improves PF strength SMD=0.35 and balance SMD=0.41 [Liang 2025].",
  "note": [
    {
      "text": "Long calf, locked knee — eccentric controls the descent",
      "authorString": "focus:internal"
    },
    {
      "text": "Lower the heels over four slow seconds",
      "authorString": "focus:external"
    },
    {
      "text": "Drop the heels just below the step edge",
      "authorString": "focus:external"
    },
    {
      "text": "Weight stays even across all toes",
      "authorString": "focus:tactile"
    }
  ],
  "extension": [
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Gastrocnemius"
        },
        {
          "url": "role",
          "valueCode": "primary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "35616000"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Soleus"
        },
        {
          "url": "role",
          "valueCode": "primary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "78376008"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Tibialis Posterior"
        },
        {
          "url": "role",
          "valueCode": "secondary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "74318005"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Peroneus Longus (Fibularis Longus)"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "59831009"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Flexor Hallucis Longus"
        },
        {
          "url": "role",
          "valueCode": "synergist"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "471000"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Tibialis Anterior"
        },
        {
          "url": "role",
          "valueCode": "lengthening"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "73508007"
          }
        }
      ]
    }
  ]
}