How to Annotate Freezing of Gait from Video: A Standardized Method Using Open-Source Software

Visually scoring freezing of gait (FOG) from video is increasingly recognized as the gold-standard for assessing FOG severity in Parkinson's disease. Surprisingly, no guidelines exist on how to visually score FOG. Here, I present a free template that can be implemented in open-source software to annotate FOG from video. I provide a user guide on how to implement the template and standardize the scoring of FOG and the percentage of time spent with FOG (% FOG). It is hoped that by disseminating this method investigators will be better able to employ % FOG as an outcome in their studies and therapeutic trials.