{
  "resourceType": "ActivityDefinition",
  "id": "front-squat",
  "url": "https://bodyiq.dev/fhir/ActivityDefinition/front-squat",
  "version": "1",
  "name": "FrontSquat",
  "title": "Front Squat",
  "status": "draft",
  "experimental": true,
  "description": "Rack a barbell across the front of the shoulders in a clean grip (elbows high, fingertips under the bar) or crossed-arm position. Squat down by bending the hips and knees while keeping the torso upright and elbows lifted, descending until the hips are at or below knee level, then drive back up to standing. The anterior bar position demands an upright trunk, making it more quadriceps-dominant and thoracic-extension intensive than the back squat.",
  "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": "front-squat",
          "display": "Front Squat"
        }
      ]
    }
  ],
  "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"
    },
    {
      "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"
    },
    {
      "coding": [
        {
          "system": "https://bodyiq.dev/fhir/CodeSystem/exercise",
          "code": "thoracic-spine",
          "display": "Thoracic Spine"
        },
        {
          "system": "http://snomed.info/sct",
          "code": "5261000",
          "display": "Structure of thoracic intervertebral disc"
        }
      ],
      "text": "Thoracic Spine"
    }
  ],
  "kind": "ServiceRequest",
  "dosage": [
    {
      "text": "For strength: 3-5 sets of 3-8 reps at roughly 70-85% 1RM, 2-3 sessions per week with at least 48 hours between sessions, consistent with general resistance-training guidelines for trained and untrained adults. For hypertrophy emphasis: 3-4 sets of 6-12 reps at moderate loads taken close to fatigue."
    }
  ],
  "usage": "Evidence: moderate. Published biomechanical comparisons of the front squat versus the back squat report broadly similar EMG activation of the quadriceps, hamstrings, and lumbar erector spinae despite the front squat being performed with meaningfully lower absolute loads, alongside lower tibiofemoral compressive forces and smaller knee extensor moments at equivalent relative intensities. This makes the front squat an efficient quadriceps stimulus per unit of spinal and knee compressive load. The upright trunk position shifts demand toward the thoracic extensors and anterior core to resist the forward-flexion moment of the anteriorly racked bar, and vastus activation tends to increase with squat depth. Hamstring activity is modest and largely stabilizing rather than prime-moving.",
  "note": [
    {
      "text": "Drive your elbows up toward the ceiling for the whole rep — if the elbows drop, the bar rolls forward."
    },
    {
      "text": "Push the floor away from you as you stand up."
    },
    {
      "text": "Keep the bar traveling in a straight vertical line over the middle of your foot."
    },
    {
      "text": "Brace your trunk 360 degrees before you descend, as if preparing to be poked in the stomach."
    }
  ],
  "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": "Adductor Magnus"
        },
        {
          "url": "role",
          "valueCode": "secondary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "23087007"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Hamstrings (Group)"
        },
        {
          "url": "role",
          "valueCode": "synergist"
        }
      ]
    },
    {
      "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": "Multifidus"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "5709001"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Rectus Abdominis"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "31243008"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "External Oblique"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "1179024003"
          }
        }
      ]
    },
    {
      "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"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Upper Trapezius"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "31764008"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Anterior 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": "Soleus"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "78376008"
          }
        }
      ]
    }
  ]
}