{
  "$schema": "https://openexercise.org/schema/v0/exercise.json",
  "aliases": [
    {
      "text": "Nordic Curl",
      "kind": "common"
    },
    {
      "text": "Nordic Hamstring Exercise",
      "kind": "common"
    },
    {
      "text": "Russian Hamstring Curl",
      "kind": "regional"
    }
  ],
  "anatomy": {
    "muscles": [
      {
        "muscle": "biceps-femoris",
        "role": "prime-mover"
      },
      {
        "muscle": "semitendinosus",
        "role": "prime-mover"
      },
      {
        "muscle": "semimembranosus",
        "role": "prime-mover"
      },
      {
        "muscle": "gastrocnemius",
        "role": "synergist"
      },
      {
        "muscle": "gluteus-maximus",
        "role": "stabilizer"
      },
      {
        "muscle": "erector-spinae",
        "role": "stabilizer"
      },
      {
        "muscle": "rectus-abdominis",
        "role": "stabilizer"
      }
    ],
    "joints": [
      {
        "joint": "knee",
        "actions": [
          "extension",
          "flexion"
        ]
      },
      {
        "joint": "hip",
        "actions": [
          "isometric-stabilization"
        ]
      },
      {
        "joint": "lumbar-spine",
        "actions": [
          "isometric-stabilization"
        ]
      }
    ]
  },
  "classification": {
    "modalities": [
      "strength",
      "rehabilitation",
      "calisthenics"
    ],
    "movement_patterns": [
      "isolation-knee-flexion"
    ],
    "mechanics": "isolation",
    "force": "pull",
    "kinetic_chain": "closed",
    "laterality": "bilateral",
    "planes": [
      "sagittal"
    ],
    "contraction": [
      "eccentric-emphasis",
      "dynamic"
    ],
    "level": "advanced"
  },
  "equipment": {
    "optional": [
      "mat",
      "strap",
      "resistance-band"
    ],
    "required": []
  },
  "external_ids": {
    "wger": "910"
  },
  "id": "oec:nordic-hamstring-curl",
  "instructions": {
    "setup": [
      "Kneel tall on a padded mat with your knees spaced hip-width apart and your ankles securely anchored by a partner, a loaded barbell, or a dedicated strap.",
      "Engage your glutes and core to form a rigid, straight line from your knees through your hips to your shoulders.",
      "Keep your arms ready in front of your chest to cushion your descent if you reach failure."
    ],
    "steps": [
      "Slowly lower your torso forward toward the floor by extending at the knees, resisting gravity entirely with your hamstrings.",
      "Maintain complete hip extension throughout the descent without allowing your hips to bend backward.",
      "Descend as far and as slowly as possible until your hamstrings can no longer hold you.",
      "Catch yourself on the floor with your hands in a controlled push-up position.",
      "Lightly push off the floor with your hands and powerfully pull with your hamstrings to return to the upright starting position."
    ],
    "breathing": "Inhale and brace your core at the top, exhale steadily as you control the descent, and breathe out forcefully as you push and pull back to the start.",
    "cues": [
      "Lock your hips in line with your torso.",
      "Brake with your hamstrings all the way down.",
      "Keep your body stiff like a board."
    ],
    "common_faults": [
      {
        "fault": "Bending at the hips (piking) during the descent to reduce the lever arm.",
        "correction": "Squeeze the glutes and maintain a straight line from your knees to your shoulders throughout the movement."
      },
      {
        "fault": "Dropping uncontrolled to the floor without resisting eccentrically.",
        "correction": "Slow the descent deliberately and use a resistance band around your chest if you cannot maintain tension for at least two to three seconds."
      }
    ],
    "safety": {
      "precautions": [
        "Place ample padding under the kneecaps to protect against excess pressure.",
        "Ensure ankles are solidly anchored before initiating the movement to prevent slipping.",
        "Warm up the hamstrings thoroughly, as the eccentric peak forces are exceptionally high."
      ],
      "spotter": "not-needed"
    }
  },
  "measurement": {
    "load": {
      "convention": "not-applicable",
      "kind": "bodyweight"
    },
    "profiles": [
      {
        "required": [
          "reps"
        ],
        "optional": [
          "tempo",
          "rpe"
        ]
      }
    ],
    "records": {},
    "reps_counted": "total"
  },
  "name": "Nordic Hamstring Curl",
  "previous_ids": [
    "oec: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: Nordic Curl",
        "url": "https://wger.de/en/exercise/910/view-base",
        "license": "CC-BY-SA-4.0",
        "author": "karly"
      }
    ]
  },
  "relations": [
    {
      "type": "progression-of",
      "target": "oec:slider-hamstring-curl"
    },
    {
      "type": "substitute-for",
      "target": "oec:lying-leg-curl"
    },
    {
      "type": "substitute-for",
      "target": "oec:seated-leg-curl"
    }
  ],
  "setup": {
    "position": "kneeling",
    "range": "full",
    "stance": {
      "kind": "parallel",
      "width": "hip"
    }
  },
  "status": "active",
  "summary": "An advanced bodyweight knee-flexion exercise that develops eccentric hamstring strength by controlling the forward descent of the torso from a kneeling position."
}