{
  "resourceType": "ActivityDefinition",
  "id": "leg-press-limited-rom",
  "url": "https://bodyiq.dev/fhir/ActivityDefinition/leg-press-limited-rom",
  "version": "1",
  "name": "LegPressLimitedRom",
  "title": "Leg Press (Limited ROM, 0-60°)",
  "status": "draft",
  "experimental": true,
  "description": "Leg press machine restricted to 0-60° knee flexion to minimize patellofemoral stress. Maximum VMO:VL ratio occurs at 60° in CKC exercises. Appropriate for early-stage patellofemoral pain when full-depth squats are too provocative. Adding isometric hip adduction increases VMO activation without increasing VL.",
  "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": "leg-press-limited-rom",
          "display": "Leg Press (Limited ROM, 0-60°)"
        }
      ]
    }
  ],
  "bodySite": [
    {
      "coding": [
        {
          "system": "https://bodyiq.dev/fhir/CodeSystem/exercise",
          "code": "knee",
          "display": "Knee"
        },
        {
          "system": "http://snomed.info/sct",
          "code": "129159008",
          "display": "Structure of femorotibial joint"
        }
      ],
      "text": "Knee"
    },
    {
      "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": "3×15-30 reps, 0-60° knee flexion, 3-5 days/week; progress depth as tolerated [APTA 2020, Neal 2024]"
    }
  ],
  "usage": "Evidence: moderate. CKC exercises: VMO:VL approaching 1:1 [Chen 2018]. Max VMO:VL at 60° knee flexion [Tang 2001]. Hip adduction during press: VMO:VL 1.14:1 [Irish 2010]",
  "note": [
    {
      "text": "Long spine, quiet trunk — quads drive the press",
      "authorString": "focus:internal"
    },
    {
      "text": "Push the platform away through both heels",
      "authorString": "focus:external"
    },
    {
      "text": "Stop the descent at the 60° marker",
      "authorString": "focus:external"
    },
    {
      "text": "Knees stay hip-width — squeeze a ball between them",
      "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": "tang-vmo-vl-2001",
      "citation": "Tang SF, Chen CK, Hsu R, Chou SW, Hong WH, Lew HL. (2001). VMO and VL Activity in OKC and CKC in PFP",
      "document": {
        "url": "https://doi.org/10.3233/ies-1995-5201"
      }
    },
    {
      "type": "citation",
      "label": "irish-vmo-vl-ckc-okc-2010",
      "citation": "Irish SE, Millward AJ, Wride J, Haas BM, Shum GL. (2010). CKC vs OKC: VMO and VL Activity",
      "document": {
        "url": "https://doi.org/10.3233/ies-1995-5201"
      }
    },
    {
      "type": "citation",
      "label": "chen-pfp-emg-2018",
      "citation": "Chen HY, Chien CC, Wu SK, Liau JJ, Jan MH. (2018). EMG of Hip and Knee Muscles in PFP: Observational Study",
      "document": {
        "url": "https://doi.org/10.1016/j.physio.2015.03.1305"
      }
    },
    {
      "type": "citation",
      "label": "miao-vmo-hip-adduction-2015",
      "citation": "Miao P, Xu Y, Pan C, Liu H, Wang C. (2015). VMO and VL During Semisquat With Hip Adduction in PFP",
      "document": {
        "url": "https://doi.org/10.1016/s1050-6411(01)00024-4"
      }
    },
    {
      "type": "citation",
      "label": "neal-pfp-best-practice-2024",
      "citation": "Neal BS, Barton CJ, Gallie R, O'Halloran P, Morrissey D. (2024). Best Practice Guide for PFP",
      "document": {
        "url": "https://doi.org/10.1680/cbpg.36505"
      }
    }
  ],
  "extension": [
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Quadriceps Femoris"
        },
        {
          "url": "role",
          "valueCode": "primary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "21989003"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Gluteus Maximus"
        },
        {
          "url": "role",
          "valueCode": "secondary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "206007"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Hamstrings (Group)"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        }
      ]
    }
  ]
}