{
  "resourceType": "ActivityDefinition",
  "id": "alfredson-eccentric-heel-drops",
  "url": "https://bodyiq.dev/fhir/ActivityDefinition/alfredson-eccentric-heel-drops",
  "version": "1",
  "name": "AlfredsonEccentricHeelDrops",
  "title": "Alfredson Protocol — Eccentric Heel Drops",
  "status": "draft",
  "experimental": true,
  "description": "Standing on a step edge, performing slow eccentric heel lowering on the affected leg. Both straight-knee (gastrocnemius bias) and bent-knee (soleus bias) versions. The gold standard for midportion Achilles tendinopathy. VISA-A improves from 49.2 to 83.6 at 5 years. 'Do-as-tolerated' protocol (avg 112 reps/day) produces similar outcomes to full 180 reps/day.",
  "useContext": [
    {
      "code": {
        "system": "http://terminology.hl7.org/CodeSystem/usage-context-type",
        "code": "user"
      },
      "valueCodeableConcept": {
        "text": "difficulty: intermediate"
      }
    }
  ],
  "topic": [
    {
      "coding": [
        {
          "system": "https://bodyiq.dev/fhir/CodeSystem/exercise",
          "code": "alfredson-eccentric-heel-drops",
          "display": "Alfredson Protocol — Eccentric Heel Drops"
        }
      ]
    }
  ],
  "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 reps both straight-knee and bent-knee, 2x daily (180 total reps/day), 7 days/week, 12 weeks. Progress load when pain-free. 'Do-as-tolerated' alternative: avg 112 reps/day [Alfredson, Stevens 2014]"
    }
  ],
  "usage": "Evidence: strong. Improved neuromuscular performance (torque, work, endurance) is the only mechanism consistently associated with clinical improvement [Malliaras 2013]",
  "note": [
    {
      "text": "Tall trunk, locked knee — calf lengthens against gravity",
      "authorString": "focus:internal"
    },
    {
      "text": "Lower the heel slowly toward the floor below the step",
      "authorString": "focus:external"
    },
    {
      "text": "Take three full seconds to drop — count it out",
      "authorString": "focus:external"
    },
    {
      "text": "Free hand on rail steadies but takes no weight",
      "authorString": "focus:tactile"
    }
  ],
  "relatedArtifact": [
    {
      "type": "citation",
      "label": "kisner-therapeutic-2017",
      "citation": "Kisner C, Colby LA, Borstad J. (2017). Therapeutic Exercise: Foundations and Techniques"
    },
    {
      "type": "citation",
      "label": "acsm-guidelines-2021",
      "citation": "American College of Sports Medicine. (2021). ACSM's Guidelines for Exercise Testing and Prescription",
      "document": {
        "url": "https://doi.org/10.4135/9781412994149.n165"
      }
    },
    {
      "type": "citation",
      "label": "stevens-alfredson-lower-volume-2014",
      "citation": "Stevens M, Tan CW. (2014). Alfredson vs Lower Volume Protocol for Achilles",
      "document": {
        "url": "https://doi.org/10.2519/jospt.2014.4720"
      }
    },
    {
      "type": "citation",
      "label": "habets-eccentric-achilles-review-2015",
      "citation": "Habets B, van Cingel RE. (2015). Eccentric Exercise in Achilles Tendinopathy: Systematic Review",
      "document": {
        "url": "https://doi.org/10.1186/s13047-015-0114-5"
      }
    },
    {
      "type": "citation",
      "label": "van-der-plas-alfredson-5year-2012",
      "citation": "van der Plas A, de Jonge S, de Vos RJ, et al.. (2012). 5-Year Follow-Up of Alfredson's Heel-Drop Programme",
      "document": {
        "url": "https://doi.org/10.1136/bjsports-2011-090035"
      }
    },
    {
      "type": "citation",
      "label": "malliaras-tendinopathy-loading-2013",
      "citation": "Malliaras P, Barton CJ, Reeves ND, Langberg H. (2013). Achilles and Patellar Tendinopathy Loading Programmes: Systematic Review",
      "document": {
        "url": "https://doi.org/10.1007/s40279-013-0019-z"
      }
    },
    {
      "type": "citation",
      "label": "martin-achilles-cpg-2018",
      "citation": "Martin RL, Chimenti R, Cuddeford T, et al.. (2018). Achilles Tendinopathy CPG Revision 2018",
      "document": {
        "url": "https://doi.org/10.2519/jospt.2018.0302"
      }
    },
    {
      "type": "successor",
      "label": "Pain-free through full bodyweight eccentric range; progress to heavily loaded HSR at 6RM building to 4x6. Alfredson's own progression list names HSR.",
      "display": "Heavy Slow Resistance (HSR) for Achilles Tendinopathy",
      "resource": "ActivityDefinition/heavy-slow-resistance-achilles"
    },
    {
      "type": "predecessor",
      "label": "If single-leg step-edge eccentrics are painful, perform flat-ground bilateral heel raises first (Alfredson's stated regression).",
      "display": "Heel Raise (Calf Raise)",
      "resource": "ActivityDefinition/heel-raise"
    }
  ],
  "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": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "74318005"
          }
        }
      ]
    }
  ]
}