{
  "resourceType": "ActivityDefinition",
  "id": "squat",
  "url": "https://bodyiq.dev/fhir/ActivityDefinition/squat",
  "version": "1",
  "name": "Squat",
  "title": "Squat",
  "status": "draft",
  "experimental": true,
  "description": "Compound lower extremity exercise. Standing hip and knee flexion-extension against gravity. Fundamental movement pattern for functional strength.",
  "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": "squat",
          "display": "Squat"
        }
      ]
    }
  ],
  "bodySite": [
    {
      "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"
    },
    {
      "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": "ankle",
          "display": "Ankle"
        },
        {
          "system": "http://snomed.info/sct",
          "code": "70258002",
          "display": "Structure of ankle joint"
        }
      ],
      "text": "Ankle"
    }
  ],
  "kind": "ServiceRequest",
  "dosage": [
    {
      "text": "3×8-12 reps, 2-3x/week; moderate intensity"
    }
  ],
  "usage": "Evidence: strong. Quad 40-70% MVIC; glute max increases with depth: partial 16.9%, parallel 28.0%, full 35.4% [Caterisano 2002]",
  "note": [
    {
      "text": "Long spine, braced trunk — hips and knees descend together",
      "authorString": "focus:internal"
    },
    {
      "text": "Push the floor away to stand",
      "authorString": "focus:external"
    },
    {
      "text": "Send the hips back as if reaching for a low chair",
      "authorString": "focus:external"
    },
    {
      "text": "Knees track over the second toe — hands on the thighs check",
      "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": "barrett-squat-depth-sex-2023",
      "citation": "Barrett KB, Sievert ZA, Bennett HJ. (2023). A Comparison of Squat Depth and Sex on Knee Kinematics and Muscle Activation",
      "document": {
        "url": "https://doi.org/10.1115/1.4062330"
      }
    },
    {
      "type": "citation",
      "label": "gorsuch-squat-depth-emg-2013",
      "citation": "Gorsuch J, Long J, Miller K, et al.. (2013). The Effect of Squat Depth on Multiarticular Muscle Activation in Collegiate Cross-Country Runners",
      "document": {
        "url": "https://doi.org/10.1519/JSC.0b013e31828055d5"
      }
    },
    {
      "type": "citation",
      "label": "coratella-squat-variations-2021",
      "citation": "Coratella G, Tornatore G, Caccavale F, et al.. (2021). The Activation of Gluteal, Thigh, and Lower Back Muscles in Different Squat Variations",
      "document": {
        "url": "https://doi.org/10.3390/ijerph18020772"
      }
    },
    {
      "type": "citation",
      "label": "mccurdy-glutmax-hamstring-2018",
      "citation": "McCurdy K, Walker J, Yuen D. (2018). Gluteus Maximus and Hamstring Activation During Selected Weight-Bearing Resistance Exercises",
      "document": {
        "url": "https://doi.org/10.1519/JSC.0000000000001893"
      }
    },
    {
      "type": "citation",
      "label": "caterisano-squat-depth-2002",
      "citation": "Caterisano A, Moss RF, Pellinger TK, et al.. (2002). The Effect of Back Squat Depth on the EMG Activity of 4 Superficial Hip and Thigh Muscles",
      "document": {
        "url": "https://doi.org/10.1519/1533-4287(2002)016<0428:teobsd>2.0.co;2"
      }
    },
    {
      "type": "citation",
      "label": "muyor-squat-lunge-emg-2020",
      "citation": "Muyor JM, Martín-Fuentes I, Rodríguez-Ridao D, Antequera-Vique JA. (2020). EMG Activity During Monopodal Squat, Forward Lunge and Lateral Step-Up",
      "document": {
        "url": "https://doi.org/10.1371/journal.pone.0230841"
      }
    },
    {
      "type": "successor",
      "label": "Progress bilateral squat to single-leg/pistol once unilateral strength and balance are adequate.",
      "display": "Single Leg Squat / Pistol Squat",
      "resource": "ActivityDefinition/single-leg-squat-pistol"
    },
    {
      "type": "successor",
      "label": "3×15 bodyweight squats to full depth with the heels flat",
      "display": "Jump Squat",
      "resource": "ActivityDefinition/jump-squat"
    },
    {
      "type": "successor",
      "label": "3×15 bodyweight squats to full depth with a neutral spine",
      "display": "Split Squat / Bulgarian Split Squat",
      "resource": "ActivityDefinition/split-squat-bulgarian"
    },
    {
      "type": "predecessor",
      "label": "The athlete drops onto the seat rather than controlling the descent",
      "display": "Sit-to-Stand",
      "resource": "ActivityDefinition/sit-to-stand"
    }
  ],
  "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": "primary"
        },
        {
          "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"
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Adductor Group (Longus/Brevis/Magnus)"
        },
        {
          "url": "role",
          "valueCode": "secondary"
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Erector Spinae Group"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "44947003"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Transversus Abdominis"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "86493009"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Gastrocnemius"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        },
        {
          "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": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "78376008"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Gluteus Medius"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "78333006"
          }
        }
      ]
    }
  ]
}