{
  "resourceType": "ActivityDefinition",
  "id": "deep-neck-extensor-endurance",
  "url": "https://bodyiq.dev/fhir/ActivityDefinition/deep-neck-extensor-endurance",
  "version": "1",
  "name": "DeepNeckExtensorEndurance",
  "title": "Deep Neck Extensor Endurance",
  "status": "draft",
  "experimental": true,
  "description": "A low-load motor-control exercise that trains the endurance and tonic activation of the deep cervical extensors — chiefly semispinalis cervicis and cervical multifidus. In quadruped, the client maintains a gentle craniocervical nod (upper cervical slight flexion) while actively extending the lower and mid cervical spine, then holds. Keeping the head-on-neck segment nodded biases the deeper, segmental extensors over the larger superficial capitis muscles, which is the point of the drill: to restore selective control and endurance rather than raw 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": "deep-neck-extensor-endurance",
          "display": "Deep Neck Extensor Endurance"
        }
      ]
    }
  ],
  "bodySite": [
    {
      "coding": [
        {
          "system": "https://bodyiq.dev/fhir/CodeSystem/exercise",
          "code": "cervical-spine",
          "display": "Cervical Spine"
        },
        {
          "system": "http://snomed.info/sct",
          "code": "68818006",
          "display": "Structure of cervical intervertebral disc"
        },
        {
          "system": "http://snomed.info/sct",
          "code": "20292002",
          "display": "Structure of atlantooccipital joint"
        }
      ],
      "text": "Cervical Spine"
    }
  ],
  "kind": "ServiceRequest",
  "dosage": [
    {
      "text": "Endurance emphasis: 1-3 sets of 8-12 slow repetitions with 5-10 second holds at end position, or a single sustained low-load hold building from 10 seconds. Perform daily or most days. Load stays low; stop the set when the deep muscles fatigue or the chin begins to poke forward (superficial substitution). Progress hold duration and repetitions before adding external load."
    }
  ],
  "usage": "Evidence: moderate. Surface and intramuscular EMG studies indicate that performing cervical extension with the craniocervical region held neutral-to-slightly-flexed increases activation of semispinalis cervicis relative to the superficial capitis muscles; this drives the nodded-head setup. Reported activation ratios vary between studies, so treat specifics as indicative rather than precise.",
  "note": [
    {
      "text": "On hands and knees, stack shoulders over wrists and hips over knees; let your head hang so your gaze is toward the floor and the back of your neck feels long."
    },
    {
      "text": "First make a subtle nod, as if tucking your chin a fingertip's width — keep this nod the entire time so the small deep muscles at the base of your neck do the lifting, not the big ones up top."
    },
    {
      "text": "Keeping the nod, slowly raise your head until the back of your neck lines up with your upper back — like lengthening the crown of your head forward and up, not cranking the head back."
    },
    {
      "text": "Move slowly and hold at the top without letting your chin poke forward; breathe normally through the hold, then lower with control."
    }
  ],
  "extension": [
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Semispinalis Cervicis"
        },
        {
          "url": "role",
          "valueCode": "primary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "44222009"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Multifidus"
        },
        {
          "url": "role",
          "valueCode": "primary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "5709001"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Semispinalis Capitis"
        },
        {
          "url": "role",
          "valueCode": "secondary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "2666009"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Splenius Cervicis"
        },
        {
          "url": "role",
          "valueCode": "secondary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "61046001"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Splenius Capitis"
        },
        {
          "url": "role",
          "valueCode": "secondary"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "1600003"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Deep Cervical Flexors"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Suboccipital Muscles"
        },
        {
          "url": "role",
          "valueCode": "stabilizer"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "244847002"
          }
        }
      ]
    },
    {
      "url": "https://bodyiq.dev/fhir/StructureDefinition/muscle-involvement",
      "extension": [
        {
          "url": "muscle",
          "valueString": "Erector Spinae Group"
        },
        {
          "url": "role",
          "valueCode": "synergist"
        },
        {
          "url": "coding",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "44947003"
          }
        }
      ]
    }
  ]
}