A mass on a stick — engineered.
Swap the mass, set the extension, and the moment arm does the work. Purpose-built for eccentric loading — measured, not guessed. Not a wearable, not a repurposed dumbbell.
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How the physics works for you
Load on a tendon is about torque, not just weight. Torque is force times the length of the lever it acts on — the moment arm. Rebow is a telescopic pole with a small weighted head at the end: extend the pole and the same small mass produces more load; retract it for less. A little mass on a long arm does the work of a much heavier weight, with far more control.
What's in the device
0.5 kg & 1 kg heads
Two interchangeable weighted heads. Combine with the extension to dial the load up or down as you progress.
Extension 0–10
A telescopic pole with marked extension increments. The setting is what turns a fixed mass into a finely tunable load.
Integral phone holder
A rigid on/off mount holds your phone as the motion sensor — so the app can pace and log each rep. See the app.
Built by an engineer, for real use
Rebow started as a tool its founder — a PhD engineer — needed and couldn't buy. Every design choice serves the loading: rigidity so the phone reads true, a clean moment datum so the numbers mean something, light enough to use twice a day without it becoming a chore.
Illustrations on this page are engineering schematics. Real product photography swaps in once the full prototype lands (est. August 2026).