Table 1.

Definition of outcome measures, as displayed in Figure1

Outcome measure	Description
Fz1	Local maximum in the vertical GRF data, normalized to body weight (BW).
Fz2	Maximum value in the vertical GRF data, normalized to BW.
LR	The steepest part of the vertical GRF curve, from stance to impact peak. Expressed in BW/s.
ALR	Average loading rate, the slope of the line from 20% to 80% of Fz1. Expressed in BW/s.
tFz1	Time from heelstrike to Fz1 in ms.
tFz2	Time from heelstrike to Fz2 in ms.
CT	Contact time, from heelstrike to toe-off in ms.

Outcome measures for the overground and treadmill data were identified with the same routine. Foot strikes were detected with a threshold of 30 Newton for both heelstrike and toe-off.