{
  "$schema": "https://openexercise.org/schema/v0/exercise.json",
  "aliases": [
    {
      "text": "Hyperextension Bench Crunch",
      "kind": "common"
    }
  ],
  "anatomy": {
    "muscles": [
      {
        "muscle": "rectus-abdominis",
        "role": "prime-mover"
      },
      {
        "muscle": "external-oblique",
        "role": "synergist"
      },
      {
        "muscle": "internal-oblique",
        "role": "synergist"
      },
      {
        "muscle": "iliopsoas",
        "role": "stabilizer"
      },
      {
        "muscle": "rectus-femoris",
        "role": "stabilizer"
      },
      {
        "muscle": "transversus-abdominis",
        "role": "stabilizer"
      }
    ],
    "joints": [
      {
        "joint": "lumbar-spine",
        "actions": [
          "flexion",
          "extension"
        ]
      },
      {
        "joint": "thoracic-spine",
        "actions": [
          "flexion",
          "extension"
        ]
      },
      {
        "joint": "hip",
        "actions": [
          "isometric-stabilization"
        ]
      }
    ]
  },
  "classification": {
    "modalities": [
      "hypertrophy",
      "strength",
      "calisthenics"
    ],
    "movement_patterns": [
      "spinal-flexion"
    ],
    "mechanics": "isolation",
    "force": "pull",
    "kinetic_chain": "closed",
    "laterality": "bilateral",
    "planes": [
      "sagittal"
    ],
    "contraction": [
      "dynamic"
    ],
    "level": "intermediate"
  },
  "equipment": {
    "optional": [
      "weight-plate"
    ],
    "required": [
      [
        "roman-chair",
        "ghd"
      ]
    ]
  },
  "external_ids": {
    "wger": "505"
  },
  "id": "oec:roman-chair-crunch",
  "instructions": {
    "setup": [
      "Sit on the Roman chair facing upward with your thighs supported by the main pad and your ankles firmly secured beneath the roller pads.",
      "Cross your arms over your chest or lightly place your fingertips beside your ears without pulling on your neck.",
      "Engage your core and lean back slightly until your torso forms a straight line with your thighs."
    ],
    "steps": [
      "Exhale and curl your ribcage down toward your pelvis by flexing your spine, squeezing your abdominals hard at the peak of the contraction.",
      "Pause momentarily at peak flexion while keeping your hips stable.",
      "Inhale and slowly uncurl your spine, returning to the starting semi-reclined alignment without hyperextending your lower back."
    ],
    "breathing": "Exhale forcefully as you curl the torso upward; inhale smoothly as you lower back down under control.",
    "cues": [
      "Ribs to hips",
      "Curl, don't hinge",
      "Keep tension on the abs throughout"
    ],
    "common_faults": [
      {
        "fault": "Swinging the torso by hinging at the hips instead of flexing the spine.",
        "correction": "Keep your hip angle relatively fixed and focus exclusively on curling your ribcage toward your pelvis."
      },
      {
        "fault": "Hyperextending the lower back excessively at the bottom of each repetition.",
        "correction": "Stop descending once your torso is parallel with your thighs to maintain continuous abdominal engagement and protect the lumbar spine."
      },
      {
        "fault": "Yanking on the neck with hands behind the head.",
        "correction": "Cross your arms across your chest or keep your fingertips gently resting at your temples."
      }
    ],
    "safety": {
      "precautions": [
        "Ensure ankle pads are securely locked in position before leaning back into the movement."
      ],
      "spotter": "not-needed"
    }
  },
  "measurement": {
    "load": {
      "kind": "bodyweight"
    },
    "profiles": [
      {
        "required": [
          "reps"
        ],
        "optional": [
          "rpe"
        ]
      }
    ],
    "records": {},
    "reps_counted": "total"
  },
  "name": "Roman Chair Crunch",
  "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: Roman Chair Crunch",
        "url": "https://wger.de/en/exercise/505/view-base",
        "license": "CC-BY-SA-3.0",
        "author": "MaddieBeasley"
      }
    ]
  },
  "relations": [
    {
      "type": "progression-of",
      "target": "oec:crunch"
    },
    {
      "type": "variation-of",
      "target": "oec:crunch"
    },
    {
      "type": "substitute-for",
      "target": "oec:decline-crunch"
    },
    {
      "type": "substitute-for",
      "target": "oec:stability-ball-crunch"
    }
  ],
  "setup": {
    "position": "seated",
    "range": "partial"
  },
  "status": "active",
  "summary": "An abdominal exercise performed on a Roman chair that targets the rectus abdominis through controlled spinal flexion while the lower body is anchored."
}