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. Author manuscript; available in PMC: 2016 Apr 18.
Published in final edited form as: Gerontechnology. 2015;13(3):359–367.

Table 1.

Perturbation characteristics; Each platform-translation perturbation comprised a 300 ms square acceleration pulse followed immediately by an equal and opposite deceleration pulse; N=normal base-of-support footwear; W=wide base-of-support footwear; L=leftward; R=rightward; F=forward; B=backward; NA=not applicable

Trial Footwear Perturbation characteristics
Stance leg Number of replicates Total number of trials
Direction Magnitude
Unconstrained (react naturally) Stance N, W L, R 2.0 m/s2, 0.6 m/s Bipedal 6 24
N, W L, R 1.0 m/s2, 0.3 m/s Bipedal 1 4
N, W F, B 2.0 m/s2, 0.6 m/s Bipedal 1 4
N, W NA NA Bipedal 2 4
Walk-in-place N, W L 2.0 m/s2, 0.6 m/s Right 3 6
N, W R 2.0 m/s2, 0.6 m/s Left 3 6
N, W F, B 2.0 m/s2, 0.6 m/s Left 1 4
N, W NA NA NA 1 2
Constrained (try not to step) N, W L, R 1.0 m/s2, 0.3 m/s Bipedal 2 8
N, W L, R 1.5 m/s2, 0.45 m/s Bipedal 2 8
N, W L, R 2.0 m/s2, 0.6 m/s Bipedal 2 8
N, W L, R 2.5 m/s2, 0.75 m/s Bipedal 2 8
N, W L, R 3.0 m/s2, 0.9 m/s Bipedal 2 8
Cued forward-step N, W B 3.0 m/s2, 0.9 m/s NA 5 10