Lots of things come into play when assessing a client’s ‘reaction time’. If we think about reaction time, in terms of driving rehab, we are probably looking at how quickly a client can produce a motor response in reaction to a change in light.
A popular measure for brake reaction is a simple reaction timer. The client is instructed to press on the accelerator until a green light appears, and then move to the brake, when the red light appears. While this is NOT a prefect test, it gives us some general information about the client’s reaction time before proceeding to the in-vehicle assessment.
Interestingly enough, when I started in driving rehab, oh say 15+ years ago, the brake reaction timer was used as a standard for some DMVs. In fact, in Maryland, you needed to perform this test, for 10 trials, with an average of 0.50 or less to be eligible to proceed with in-vehicle assessment. Over the years, evidence supporting this standard was no longer strong, and this screening tool was found to be not as effective as we had once thought. Wondering if any of my DRS friends might have some additional thoughts or recommended reading on this?
Back to the idea of brake reaction… flip on your OT task analysis lens and you start to realize there are many variables that impact this task from vision, to processing, notice & response, coordination, sensation, and motor movement.
A deficit in just one of these performance skills can throw off performance. This is one of the reasons, I still used this as a screening tool, but always do this after I have already tested these performance skills individually (or as individually as I can).
I mention the numerous performance skills because understanding your clients diagnosis and deficits will impacting potential for improvement and response to interventions. If the deficit is because of a change in the brain from dementia, interventions might result in an improved motor pattern, but it won’t impact the underlying concerns. On the other hand, if the deficit is related to a muscle weakness, then we can focus interventions to improve strength, speed, & coordination.
In some situations, I’m thinking mainly neurological conditions, medications may also impact motor performance and be something to consider as well. Bottom line, I encourage you to apply an approach of evaluation & assessment, determination of performance skill deficit, and then intervene from there.