GTD Scientific

08/31/2026

𝐏𝐫𝐨𝐧𝐞 𝐑𝐞𝐬𝐭𝐫𝐚𝐢𝐧𝐭 𝐑𝐢𝐬𝐤 𝐈𝐬 𝐀𝐛𝐨𝐮𝐭 𝐭𝐡𝐞 𝐖𝐡𝐨𝐥𝐞 𝐏𝐢𝐜𝐭𝐮𝐫𝐞

The prone position alone is generally well tolerated by healthy individuals. The concern grows when risk factors such as struggle, obesity, drugs, anxiety, downward force, immobilization, hard surfaces, and time begin to combine.

That’s the final takeaway from our Prone Restraint series: it’s the combination that matters.

Learn more in our free course, The Science & Experience of Prone Restraint Risk Mitigation, or our comprehensive paid course, The Science of Prone Restraint Deaths.

The final video in our series looks at why prone restraint risk mus...

08/24/2026

𝐖𝐡𝐞𝐫𝐞 𝐈𝐧𝐣𝐮𝐫𝐲 𝐁𝐢𝐨𝐦𝐞𝐜𝐡𝐚𝐧𝐢𝐜𝐬 𝐌𝐞𝐞𝐭𝐬 𝐏𝐞𝐫𝐬𝐨𝐧𝐚𝐥 𝐒𝐚𝐟𝐞𝐭𝐲
GTD Scientific recently collaborated with Personal Safety Tactics by Sgt. Clive Milligan (ret.) with a video on Physics, Force and Mechanisms of Human Injury, featuring our team at GTD.
The video explores several topics including: How force and gravity produce injury; how biomechanics applies to both you and the person you encounter; and how understanding vulnerable anatomy can be applied to assist you in defending yourself in a violent encounter.
A practical look at the science of human injury and what it means when physical encounters happen in the real world.
Watch the full video at Personal Safety Tactics.

Insights from an interview with Dr. Geoff Desmoulin on how force and trauma affect the human body Understanding the science behind how injuries occur from force and gravity How biomechanical science applies to both you and the subject/suspect you encounter Demonstrations of vulnerable parts of the h...

08/17/2026

𝐖𝐡𝐚𝐭 𝐂𝐡𝐚𝐧𝐠𝐞𝐬 𝐖𝐡𝐞𝐧 𝐘𝐨𝐮 𝐁𝐫𝐞𝐚𝐭𝐡𝐞 𝐈𝐧 𝐏𝐫𝐨𝐧𝐞 𝐏𝐨𝐬𝐢𝐭𝐢𝐨𝐧?

Normally, the diaphragm moves downward and the abdomen expands during inspiration. In the prone position, that expansion can be restricted, requiring the respiratory muscles to work harder.

For a healthy person at rest, this may be well tolerated. During prone restraint, however, other risk factors can add to that respiratory workload.

Learn more in our free course, The Science & Experience of Prone Restraint Risk Mitigation, or our comprehensive paid course, The Science of Prone Restraint Deaths.

Prone positioning changes the mechanics of breathing. See what happ...

08/10/2026

𝐓𝐮𝐫𝐧𝐢𝐧𝐠 𝐩𝐫𝐨𝐧𝐞 𝐫𝐞𝐬𝐭𝐫𝐚𝐢𝐧𝐭 𝐬𝐜𝐢𝐞𝐧𝐜𝐞 𝐢𝐧𝐭𝐨 𝐬𝐨𝐦𝐞𝐭𝐡𝐢𝐧𝐠 𝐨𝐟𝐟𝐢𝐜𝐞𝐫𝐬 𝐜𝐚𝐧 𝐮𝐬𝐞 𝐢𝐧 𝐭𝐡𝐞 𝐦𝐨𝐦𝐞𝐧𝐭.

In a new Police1 article, Chief James Gerace and GTD Scientific’s Dr. Geoffrey Desmoulin connect the physiology and biomechanics of prone restraint with four simple operational rules.

The goal is simple: help officers recognize developing medical risk and respond with practical actions that are easy to remember when circumstances are anything but simple.

Four rules help officers reduce risks during prone restraint.

08/03/2026

𝐍𝐨𝐭 𝐀𝐥𝐥 𝐏𝐫𝐨𝐧𝐞 𝐑𝐞𝐬𝐭𝐫𝐚𝐢𝐧𝐭 𝐑𝐞𝐥𝐚𝐭𝐞𝐝 𝐑𝐢𝐬𝐤 𝐈𝐬 𝐈𝐦𝐦𝐞𝐝𝐢𝐚𝐭𝐞.

Research has shown that some respiratory changes continue to develop the longer a person remains restrained. Even in healthy volunteers, lung volume decreased over time in certain restraint positions following exercise.

Prone restraint is not a static event. The physiological effects can change from one minute to the next, making continuous assessment and timely repositioning important considerations.

The physiological effects of prone restraint can evolve over time. ...

07/27/2026

𝐂𝐚𝐧 𝐭𝐡𝐞 𝐠𝐫𝐨𝐮𝐧𝐝 𝐛𝐞𝐧𝐞𝐚𝐭𝐡 𝐬𝐨𝐦𝐞𝐨𝐧𝐞 𝐚𝐟𝐟𝐞𝐜𝐭 𝐡𝐨𝐰 𝐡𝐚𝐫𝐝 𝐭𝐡𝐞𝐲 𝐡𝐚𝐯𝐞 𝐭𝐨 𝐛𝐫𝐞𝐚𝐭𝐡𝐞? 𝘠𝘦𝘴.

Hard surfaces increase the work of breathing compared to more compliant surfaces. Even small amounts of surface compression can reduce the effort required to breathe while a person is restrained in the prone position.

When operationally feasible, choosing a more compliant surface may help reduce one of the many physiological stresses associated with restraint.

Hard surfaces increase the work of breathing. Surface choice can be...

07/20/2026

𝐈𝐬 𝐢𝐦𝐦𝐨𝐛𝐢𝐥𝐢𝐳𝐚𝐭𝐢𝐨𝐧 𝐭𝐡𝐞 𝐬𝐚𝐦𝐞 𝐚𝐬 𝐝𝐨𝐰𝐧𝐰𝐚𝐫𝐝 𝐟𝐨𝐫𝐜𝐞?
𝘕𝘰𝘵 𝘯𝘦𝘤𝘦𝘴𝘴𝘢𝘳𝘪𝘭𝘺.

Downward force compresses the body. Immobilization prevents a person from repositioning themselves to improve breathing. While the two often occur together, they are different biomechanical risk factors.

Recognizing the difference can help investigators, trainers, and officers better understand restraint related respiratory risk.

Our free course, The Science & Experience of Prone Restraint Risk Mitigation, explores immobilization and the other key physiological and biomechanical factors that influence risk.

Immobilization and downward force are different biomechanical risk ...

07/13/2026

Our work on the physiology and biomechanics of prone restraint respiration has been summarized in a practical briefing published in Applied Police Briefings.

This article distills key takeaways from the original research, focusing on how prone positioning, continued struggle, and interacting risk factors can affect respiration in real-world scenarios.

Designed for those involved in training, supervision, and review, it offers a concise overview of the science to support more informed discussions around prone restraint risk.

Category: Press Article Publication: Applied Police Briefings/Spring 2026. Author: Geoffrey T. Desmoulin Summary: This briefing explains that prone restraint in calm, cooperative people typically causes only small breathing changes, but risk […]

07/03/2026

Here's to a great 4th of July weekend for our clients, colleagues, and friends across the United States.

Enjoy the break, make some memories, and we'll see you next week.

07/01/2026

Proudly Canadian. Have a good day, eh!