Lower extremities task of pressing an “accelerator” or a “brake”: association with traffic accidents in older drivers – a preliminary study

Traffic accidents by older drivers are a social urgent problem. The National Police Agency (NPA) in Japan has institutionalized the Cognitive Function Test (NPA test) for renewal of a driver’s license for older adults. However, driving ability cannot be simply evaluated by usual cognitive tests on the desk. OBJECTIVE: It is important to add an on-road test, but if not possible, we can use simulators. Before doing simulators, it is important to use the right foot to control the accelerator and brake pedals. We applied the Posner paradigm (visual attention test) for lower extremities. METHODS: The participants were older adults. They and their families had anxiety about their driving. The 66 participants (44 men and 22 women) were divided into groups with and without experience of a traffic accident, and the following tests were examined: General cognitive and executive function tests, the NPA test, and an original Lower Extremity Reaction Test. Each participant was asked to press the “brake” or “accelerator” pedal by the right foot as quickly as possible in response to a traffic situation shown on the screen. RESULTS: Compared to participants with favorable reactions to the Lower Extremity Reaction Test, those with poor reaction time tended to have more traffic accidents (OR=6.82), rather than the result of the NPA test. CONCLUSIONS: The results suggest that the probability of having a traffic accident can be better evaluated using the Lower Extremity Reaction Test.