rzen
7c241ec44c
render.py --export bundles the 25 new motion rigs and info pages; figure-fixtures.json regenerated for all 47 (the Swift solver reproduces every new motion, including negative-y pins and the new prop uses). The fixture count assertion moves to 47, and the no-bundled-motion test now uses Treadmill - a permanent COVERAGE.md exclusion - since Bench Press exists. 48 tests green; watch target builds. Coverage handoff complete - TODO-coverage.md retired. Claude-Session: https://claude.ai/code/session_01HJDQQDA9QdP8zByg43H5v3
40 lines
1.1 KiB
Markdown
40 lines
1.1 KiB
Markdown
# Back Extension
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The roman-chair hinge — hips anchored on the pad, fold forward, then raise
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the trunk back in line with the legs.
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- **Category:** Main circuit
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- **Type:** Machine-based back extension (hip hinge)
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- **Targets:** Spinal erectors, glutes, hamstrings
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- **Prescription:** 3 × 10–15
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## Setup
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Set the pad so its top edge sits at the crease of your hips — you must be
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able to fold freely over it. Hook your heels under the ankle rollers,
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cross your arms over your chest.
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## Execution
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1. Fold forward over the pad with a controlled, mostly-flat back.
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2. Lower until the hamstrings stop you, without going slack.
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3. Squeeze glutes and back to raise the trunk until it lines up with the
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legs — no higher.
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## Cues
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- Movement comes from the hips with the back held long.
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- Rise to a straight body line, not into an arch.
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- Slow down; momentum does nothing here.
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## Common Mistakes
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- Pad set too high, blocking the hinge.
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- Hyperextending past the body line at the top.
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- Swinging up with momentum.
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## Progression
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Slow the lowering phase, add a pause at the top, then hold a plate to the
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chest for load.
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