{
  "name": "Back Extension",
  "primary": 2,
  "working": ["spine"],
  "props": [
    {"type": "scene", "shapes": [
      {"kind": "line", "pts": [[102, 124], [154, 106]], "w": 9, "depth": 8},
      {"kind": "line", "pts": [[130, 122], [130, 150]], "w": 5},
      {"kind": "line", "pts": [[58, 142], [88, 142]], "w": 5, "depth": 6}
    ]},
    {"type": "roller", "at": ["foot_r", "foot_l"], "r": 4.5, "side": 1, "back": 4}
  ],
  "frames": [
    {
      "hold": 0.4, "tween": 1.0,
      "root": {"pos": [150, 102], "pitch": 112},
      "spine": [0, 12],
      "neck": 1, "head": -30,
      "shoulder_r": -10, "elbow_r": 114,
      "shoulder_l": -10, "elbow_l": 114,
      "hip_r": 48, "knee_r": 12, "ankle_r": 12,
      "hip_l": 48, "knee_l": 12, "ankle_l": 12,
      "pins": {"foot_r": [72, 136], "foot_l": [76, 138]}
    },
    {
      "hold": 0.6, "tween": 1.1,
      "root": {"pos": [150, 102], "pitch": 65},
      "spine": [0, -6],
      "neck": 5, "head": -55,
      "shoulder_r": 30, "elbow_r": 140,
      "shoulder_l": 30, "elbow_l": 140,
      "hip_r": 2, "knee_r": 12, "ankle_r": 12,
      "hip_l": 2, "knee_l": 12, "ankle_l": 12,
      "pins": {"foot_r": [72, 136], "foot_l": [76, 138]}
    }
  ]
}