Abstract: The present invention provides a reaction time measurement system that includes a hard-wired or battery-powered accelerometer module attached to a starting block or platform to detect acceleration when a contestant moves. Although the block is grossly stationary, it undergoes slight movement and mechanical vibration, so the accelerometer produces an output signal. A filter or a processing unit in the module processes the output signal to define the reaction time or moment when the athlete starts to leave the block. Preferably the module removably attaches to the starting block by a rigid coupling, and its processor stores and annotates the accelerometer signal. A link or connector signals the reaction time, or the stored signal on request, to a central monitor at which false start detection determination are made and records created.