Effect of knee brace type on braking response time during automobile driving

To assess driving ability (brake response time [BRT]) with commonly used knee braces.

Sixty-four healthy participants (32 women and 32 men) participated in our study. BRT was assessed using a custom-made driving simulator. We assessed BRT for 5 different commonly used knee braces (right leg) used in 9 different settings: without a knee brace (control group); with a typical postoperative knee brace with adjustable range of motion (ROM) and the settings of 0° to 30°, 0° to 60°, 0° to 90°, and 20° to 90° (extension and flexion); and with an unloading knee brace for moderate to severe unicompartmental osteoarthritis, an orthosis for ligament instabilities, a knee brace for patellofemoral disorders, and an elastic knee bandage.

The 64 participants (mean age, 33.5 years) showed significantly impaired BRT with the typical postoperative brace set at an ROM of 0° to 30° (673 milliseconds, P < .001), ROM of 0° to 60° (629 milliseconds, P < .001), ROM of 0° to 90° (607 milliseconds, P = .001), and ROM of 20° to 90° (602 milliseconds, P = .005) compared with the control group. However, no such impaired BRT was found for any other investigated knee brace.

Right-sided ROM-restricting knee braces involve significant impairment of BRT in healthy participants. No such prolonged BRT was found for a patellofemoral realignment brace, a ligament brace, a valgus/osteoarthritis brace, or an elastic knee bandage. However, our findings should be viewed in light of the limitations of the study, which are (1) the lack of a defined decrease in BRT that could lead to an accident and (2) uncertainty of whether the statistical differences are also clinically important.

Level II, lesser-quality randomized controlled trial.