Table 1 Reactive balance test outcome measures

Visuomotor Reaction Time = averaged total visuomotor reaction time

Accuracy = (Total number of stimuli – (missed stimuli + multiple attempts needed + decision errors))/100

- Missed stimulus = failed to extinguish LED-light

- Multiple attempts = reaching from standardized position, but failed to extinguish the LED-light from the first time; second or third attempt needed

- Decision error = initiating movement in wrong direction

Balance error = number of balance errors [25]

- Minor balance error = looking for balance but able to start from standard position at stimulus onset or looking for balance during reach

- Major balance error = not starting from standard position at stimulus onset or during stimulus presentation caused by hand or foot on floor; stepping off the YBT

- Predefined balance errors = moving hands off the hips; step, stumble or fall; Abduction or flexion of the hip while looking for balance; lifting the forefoot or heel off the testing surface; placing the free foot on the floor; remaining out of the proper testing position for greater than 2 s