{
  "resourceType": "ActivityDefinition",
  "id": "prone-er-90-abduction",
  "url": "https://bodyiq.dev/fhir/ActivityDefinition/prone-er-90-abduction",
  "version": "1",
  "name": "ProneEr90Abduction",
  "title": "Prone External Rotation at 90° Abduction",
  "status": "draft",
  "experimental": true,
  "description": "Lying prone with shoulder at 90° abduction off edge of table, externally rotating a light weight. Produces the greatest supraspinatus (82% MVIC), middle deltoid (87%), and posterior deltoid (88%) activation among ER exercises. Teres minor becomes more important as ER at 90° ABD (TM:infraspinatus ratio 1.21). Late-stage exercise requiring adequate scapular stability and pain-free 90° ABD.",
  "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": "prone-er-90-abduction",
          "display": "Prone External Rotation at 90° Abduction"
        }
      ]
    }
  ],
  "bodySite": [
    {
      "coding": [
        {
          "system": "https://bodyiq.dev/fhir/CodeSystem/exercise",
          "code": "shoulder",
          "display": "Shoulder"
        },
        {
          "system": "http://snomed.info/sct",
          "code": "85537004",
          "display": "Structure of glenohumeral joint"
        }
      ],
      "text": "Shoulder"
    }
  ],
  "kind": "ServiceRequest",
  "dosage": [
    {
      "text": "3×8-15 reps, 3 days/week; late-stage exercise — introduce after pain-free 90° ABD achieved [Reinold 2004]"
    }
  ],
  "usage": "Evidence: strong. Supraspinatus 82% MVIC, middle deltoid 87%, posterior deltoid 88% [Reinold 2004]. Teres minor-to-infraspinatus ratio 1.21±0.23 at 90° ABD [Kurokawa 2014]",
  "note": [
    {
      "text": "Long spine, packed scapula — rotation comes from the back of the cuff",
      "authorString": "focus:internal"
    },
    {
      "text": "Rotate the knuckles toward the ceiling",
      "authorString": "focus:external"
    },
    {
      "text": "Lift the dumbbell along an arc above the elbow",
      "authorString": "focus:external"
    },
    {
      "text": "Towel under the upper arm stays trapped",
      "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": "reinold-rotator-cuff-emg-2004",
      "citation": "Reinold MM, Wilk KE, Fleisig GS, et al.. (2004). Electromyographic Analysis of the Rotator Cuff and Deltoid Musculature During Common Shoulder External Rotation Exercises",
      "document": {
        "url": "https://doi.org/10.2519/jospt.2004.34.7.385"
      }
    },
    {
      "type": "citation",
      "label": "ha-infraspinatus-selective-2013",
      "citation": "Ha SM, Kwon OY, Cynn HS, et al.. (2013). Selective Activation of the Infraspinatus Muscle",
      "document": {
        "url": "https://doi.org/10.4085/1062-6050-48.2.18"
      }
    },
    {
      "type": "citation",
      "label": "kurokawa-er-pet-imaging-2014",
      "citation": "Kurokawa D, Sano H, Nagamoto H, et al.. (2014). Shoulder ER Muscle Activity Pattern: PET Imaging in Adduction vs Abduction",
      "document": {
        "url": "https://doi.org/10.1016/j.jse.2013.12.021"
      }
    },
    {
      "type": "citation",
      "label": "yu-prone-er-strategies-2021",
      "citation": "Yu IY, Jung IG, Kang MH, Oh JS. (2021). Strategies for Controlling Axial Shoulder Rotation Change Muscle Activity",
      "document": {
        "url": "https://doi.org/10.1016/j.jse.2020.08.031"
      }
    },
    {
      "type": "citation",
      "label": "sung-shoulder-abduction-angle-2026",
      "citation": "Sung DH, Kim S, Lee J, et al.. (2026). Effects of Shoulder Abduction Angle and Elastic Band on Shoulder Muscle Activity",
      "document": {
        "url": "https://doi.org/10.1038/s41598-025-34767-w"
      }
    }
  ],
  "extension": [
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Infraspinatus"
        },
        {
          "url": "role",
          "valueCode": "primary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "72573008"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Teres Minor"
        },
        {
          "url": "role",
          "valueCode": "primary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "51159009"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Posterior Deltoid"
        },
        {
          "url": "role",
          "valueCode": "secondary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "35259002"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Supraspinatus"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "6423006"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Middle Deltoid"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "35259002"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Subscapularis"
        },
        {
          "url": "role",
          "valueCode": "lengthening"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "90588001"
          }
        }
      ]
    }
  ]
}