Don't Wait to Break™
A leg length and gait System, built directly from Dr Jo Abbott's PhD research. Most of us wait until something gives way before we look at how we move. This System is being built so you don't have to.
This page introduces what is coming. The research it stands on is already public, and growing, in the Living Research library.
A leg length difference is not always about bone.
Many people are told that one leg is longer than the other. Dr Jo's research looks at a different question: whether that difference is really about bone length, or about the position the pelvis and leg are held in as you walk.
Her work reads many leg length differences as functional: the result of a leg staying locked at one point in the gait cycle instead of moving freely through it. That changes what you do about it, and it is the thinking Don't Wait to Break™ is built on.
True difference
A structural difference in the length of the bones themselves.
Functional difference
A difference that appears because of how the pelvis and leg are positioned and move, rather than bone length.
Why it matters
A functional difference is something that can change. Knowing which you have points to the right kind of support.
Measured only by a HODA-A™ clinician. Followed in the app.
Don't Wait to Break™ is not a generic exercise plan, and it cannot be started from a self-test. Every programme begins with a measurement taken by a clinician certified to HODA-A™ Level 2, and by no one else.
Not any clinician. A HODA-A™ Level 2 clinician is trained and calibrated to work as a measurement instrument, under a framework built on COSMIN measurement standards. They assess your leg length difference and which point in the gait cycle, if any, a leg is locked in.
Your clinician prescribes the programme that matches your measured pattern: heel strike, midstance or heel-off.
Your programme lives in the app as a one-off prescribed programme, so you can follow it at home at your own pace.
A prescription is only as good as the measurement it rests on.
Hands-on assessment is usually treated as a skill. HODA-A™ treats it as measurement: the clinician is the instrument, and the instrument is trained, calibrated and checked. That is why this System is measured only by HODA-A™ clinicians.
Explore HODA-A™ →The research is public. The System is catching up.
Don't Wait to Break™ grows out of Dr Jo's passive gait research: years of clinical assessments linking leg length difference, gait-phase locking and musculoskeletal injury. That work is published openly as Living Research, updated as new people are assessed, and anyone can explore the data.
When the System launches, this page will link each programme back to the evidence behind it.
People in the passive gait dataset
Assessed in Dr Jo's clinical and occupational health work.
Moved optimally through gait
When assessed passively. This is a clinic sample, not the general population.
Where Don't Wait to Break™ is up to.
This System is being built in the open. Here is where each part stands today.
Published as Living Research, with interactive explorers updated as new assessments are added.
Measurement is carried out only by clinicians certified to HODA-A™ Level 2.
Heel strike, midstance and heel-off programmes are being written and filmed.
It will appear in the Dr Jo Abbott Systems™ app and on this page when it is ready.
In the meantime
If back pain is part of your story, Back Pain Systems™ is live now. If you'd like to talk about your own gait or leg length, book a free chat with Dr Jo.
Research-informed, not a diagnosis.
This page describes a System in development and the research behind it. It is educational, not a diagnosis, and it does not replace an assessment by a qualified clinician. If you have new, severe or worsening pain, please seek medical advice.
Don't Wait to Break™, Dr Jo Abbott Systems™, The Body Systems™, Back Pain Systems™ and HODA-A™ are trademarks of Dr Jo Abbott. Living Research data © Dr Jo Abbott 2026, shared as aggregate data under CC BY-NC-ND 4.0. Launch dates are not yet confirmed.