{
  "$schema": "https://openexercise.org/schema/v0/exercise.json",
  "aliases": [
    {
      "text": "Natural Leg Extension",
      "kind": "common"
    },
    {
      "text": "Bodyweight Leg Extension",
      "kind": "common"
    },
    {
      "text": "Reverse Nordic",
      "kind": "abbreviation"
    }
  ],
  "anatomy": {
    "muscles": [
      {
        "muscle": "rectus-femoris",
        "role": "prime-mover"
      },
      {
        "muscle": "vastus-lateralis",
        "role": "synergist"
      },
      {
        "muscle": "vastus-medialis",
        "role": "synergist"
      },
      {
        "muscle": "vastus-intermedius",
        "role": "synergist"
      },
      {
        "muscle": "gluteus-maximus",
        "role": "stabilizer"
      },
      {
        "muscle": "rectus-abdominis",
        "role": "stabilizer"
      },
      {
        "muscle": "iliopsoas",
        "role": "stabilizer"
      }
    ],
    "joints": [
      {
        "joint": "knee",
        "actions": [
          "flexion",
          "extension"
        ]
      },
      {
        "joint": "hip",
        "actions": [
          "isometric-stabilization"
        ]
      },
      {
        "joint": "lumbar-spine",
        "actions": [
          "isometric-stabilization"
        ]
      }
    ]
  },
  "classification": {
    "modalities": [
      "calisthenics",
      "strength",
      "rehabilitation"
    ],
    "movement_patterns": [
      "isolation-knee-extension"
    ],
    "mechanics": "isolation",
    "force": "push",
    "kinetic_chain": "closed",
    "laterality": "bilateral",
    "planes": [
      "sagittal"
    ],
    "contraction": [
      "dynamic",
      "eccentric-emphasis"
    ],
    "level": "intermediate"
  },
  "equipment": {
    "optional": [
      "mat",
      "resistance-band"
    ],
    "required": []
  },
  "external_ids": {
    "wger": "909"
  },
  "id": "oec:reverse-nordic-curl",
  "instructions": {
    "setup": [
      "Assume a tall-kneeling position on a padded mat with your knees spaced hip-width apart.",
      "Point your toes behind you with the tops of your feet flat against the floor.",
      "Squeeze your glutes and brace your abdominals to align your shoulders, hips, and knees in a straight line."
    ],
    "steps": [
      "Keeping your torso and thighs completely rigid, slowly lean your entire body backward by bending at the knees.",
      "Lower yourself under control as far as comfortable or until your quadriceps are fully stretched.",
      "Drive through your shins and contract your quadriceps to extend your knees and pull your body back up to the starting tall-kneeling position."
    ],
    "breathing": "Inhale as you lower your body backward; exhale as you pull yourself back up to the top.",
    "cues": [
      "Stay locked in a straight line from knees to shoulders",
      "Do not break at the hips",
      "Control the descent"
    ],
    "common_faults": [
      {
        "fault": "Flexing at the hips and sitting back toward the heels.",
        "correction": "Squeeze the glutes and maintain complete hip extension throughout the entire range of motion."
      },
      {
        "fault": "Hyperextending the lumbar spine to create an illusion of deeper lean.",
        "correction": "Brace the core tight and keep the ribcage down to keep the spine neutral."
      }
    ],
    "safety": {
      "precautions": [
        "Use knee padding to protect the joint from hard surfaces.",
        "Only descend through a pain-free range of motion, as this movement places high tensile stress on the patellar tendon."
      ],
      "spotter": "not-needed"
    }
  },
  "measurement": {
    "load": {
      "kind": "bodyweight"
    },
    "profiles": [
      {
        "required": [
          "reps"
        ],
        "optional": [
          "rpe",
          "tempo"
        ]
      }
    ],
    "records": {},
    "reps_counted": "total"
  },
  "name": "Reverse Nordic Curl",
  "provenance": {
    "generated": [
      "/name",
      "/summary",
      "/classification",
      "/anatomy",
      "/equipment",
      "/measurement",
      "/instructions",
      "/setup",
      "/relations"
    ],
    "license": "CC-BY-SA-4.0",
    "review": {
      "status": "machine-generated",
      "model": "gemini-3.8-flash",
      "at": "2026-10-31"
    },
    "sources": [
      {
        "title": "wger: Reverse Nordic Curl",
        "url": "https://wger.de/en/exercise/909/view-base",
        "license": "CC-BY-SA-4.0",
        "author": "karly"
      }
    ]
  },
  "relations": [
    {
      "type": "substitute-for",
      "target": "oec:leg-extension"
    }
  ],
  "setup": {
    "position": "kneeling",
    "range": "full",
    "stance": {
      "kind": "parallel",
      "width": "hip"
    }
  },
  "status": "active",
  "summary": "A bodyweight exercise performed from a tall-kneeling position that challenges the quadriceps through loaded eccentric and concentric knee extension."
}