THURSDAY, Dec. 23 (HealthDay News) -- Driving is a bad idea for people who have to wear a cast, splint or brace while recovering from an injury or surgery to their right foot, a new study reports.

The study authors found that it takes much longer to brake when a driver is wearing an ankle immobilization device than when wearing normal footwear.

The researchers measured emergency braking time in volunteers using a brake adapted for use by the left foot, or wearing a short leg cast, a controlled ankle-motion boot, or normal footwear.

The investigators found that, compared with a driver wearing normal footwear, those wearing a device or with adapted brakes in a car traveling at 60 miles per hour would travel: an additional 9.2 feet during emergency breaking if the driver is wearing a right lower-extremity controlled-ankle-motion boot; an additional 6.1 feet if the driver is wearing a right lower-extremity short leg cast; an additional 6 feet if the driver is using a left-foot braking adapter.

In addition, compared with a driver wearing normal footwear, those wearing a device or with adapted brakes in a car traveling at 35 miles per hour would travel an extra 5.4 feet, 3.6 feet and 3.5 feet, respectively, which might mean the difference between avoiding or having a collision, the researchers noted.

The study is published in the Dec. 15 issue of the Journal of Bone and Joint Surgery.

"We did not find a device that was as safe as normal footwear. We only tested emergency braking situations, but it's reasonable to assume that if a person cannot stop quickly in an emergency, it may not be safe for that person to be driving," Dr. Thomas Dowd, an orthopedic surgeon at Brooke Army Medical Center in Fort Sam Houston, Texas, said in a journal news release.

"Based on our findings, we cannot recommend that any patient return to driving using a brake adapter or wearing an immobilization device on the right foot. Orthopedic surgeons need to educate their patients about these safety concerns when discussing the best time to begin driving again," Dowd added.

More information

The American Podiatric Medical Association has more about foot and ankle injuries.