Static reactive balance
standstill
Participants stood on the CAREN while the platform and treadmill belts provided sudden perturbations. The platform could shift (move in the horizontal plane) or tilt (move into a sloping position) to anterior, posterior, left and right. The treadmill belt could unilaterally accelerate from standstill. In the second and third parts of the first training session, training difficulty started at the lowest difficulty level for each participant and could be progressed individually over 7 difficulty levels. Details on perturbation characteristics for each difficulty level were published previously [