Army researchers are recommending that patients not drive with an immobilization device on their right foot, based on a study suggesting that such devices significantly increase braking response time.
Investigators from Brooke Army Medical Center in Fort Sam Houston, TX, analyzed braking response in 35 volunteers using a driving simulator under four conditions: shoes only, wearing a controlled-ankle-motion boot, wearing a removable short leg cast, and using an adapter to allow braking with the left foot.
Mean total-brake response time for the three experimental conditions was significantly greater than the shoes-only control condition. Specifically, a driver traveling 35 miles per hour would travel an additional 5.4 feet when wearing a controlled-motion boot, an additional 3.6 feet while wearing a removable short leg cast, and an additional 3.5 feet while using a left-foot adapter.
In the study, which was published in the December issue of the Journal of Bone and Joint Surgery, the authors noted that most insurers are not obligated to cover accidents in which the driver was recovering from an earlier injury.