Diabetic Driving Studies-Part 3: A Comparison of Mean Brake Response Time Between Neuropathic Diabetic Drivers With and Without Foot Pathology

We have previously demonstrated an abnormally delayed mean brake response time and an increased frequency of abnormally delayed brake responses in a group of neuropathic diabetic drivers compared with a control group of drivers with neither diabetes nor lower extremity neuropathy. The objective of the present case-control study was to compare the mean brake response time between neuropathic diabetic drivers with and without specific diabetic foot pathology. The braking performances of the participants were evaluated using a computerized driving simulator with specific measurement of the mean brake response time and the frequency of abnormally delayed brake responses. We analyzed a control group of 20 active drivers with type 2 diabetes, lower extremity neuropathy, and no history of diabetic foot pathology and an experimental group of 20 active drivers with type 2 diabetes, lower extremity neuropathy, and a history of diabetic foot pathology (ulceration, amputation, and/or Charcot neuroarthropathy) from an urban U.S. podiatric medical clinic. Neuropathic diabetic drivers without a history of specific foot pathology demonstrated an 11.11% slower mean brake response time (0.790 ± 0.223 versus 0.711 ± 0.135 second; p < .001), with abnormally delayed reactions occurring at a similar frequency (58.13% versus 48.13%; p = .0927). Both groups demonstrated a mean brake response time slower than a suggested threshold of 0.70 second. The results of the present investigation provide evidence that diabetic patients across a spectrum of lower extremity sensorimotor neuropathy and foot pathology demonstrate abnormal automobile brake responses and might be at risk of impaired driving function.