Testing was performed in the gait laboratory of the City Hospital Waid in Zurich, Switzerland. To measure steady state walking, the central m active sensor area of the GAITRite® system was used as the test distance. During the measurements, the subjects walked on the walkway while wearing their own comfortable clothing and low-heeled habitual shoes. Since mean values of eight strides have been shown to be appropriately representing gait characteristics and can be considered as representative of normal gait [33] we ensured the capturing of at least 25 steps per test condition. Each subject was instructed to walk the walkway three times, in randomised order, at I) self-selected comfortable speed, II) a.
