Table 1.

Quantitative results for fits to gait measures with respect to speed. Fit parameters include trend value (means $\pm$ 95% confidence interval, CI) and offsets (means $\pm$ s.d.). Linear fits to speed were performed for all measures except for known nonlinear relations for step length, step period, double support period, and COM work phases (collision, rebound, reload, and push-off). $R^2$ values indicate the goodness of fit, and P-values indicate statistical significance of the trend (*$P<0.05$). Fits were performed on normalized data. Quantities are reported in dimensionless form, with body mass, gravitational acceleration and leg length as base variables.

Gait measure	Coefficient (mean $\pm$ CI)	Offset (mean $\pm$ s.d.)	$R^2$	$P$
Step Length	0.577 $\pm$ 0.061	1.243 $\pm$ 1.135	0.949	7.25e-16*
Step Width	0.068 $\pm$ 0.069	0.132 $\pm$ 0.065	0.974	5.27e-02
Step Length RMS	0.007 $\pm$ 0.028	0.017 $\pm$ 0.006	0.661	6.08e-01
Step Width RMS	0.049 $\pm$ 0.012	0.010 $\pm$ 0.005	0.921	9.11e-09*
Step Period	$-0.423\pm 0.061$	1.243 $\pm$ 1.135	0.914	5.40e-13*
Double Support Period	$-0.721\pm 0.084$	0.257 $\pm$ 1.159	0.937	6.15e-15*
COM Work Rate (pos)	0.031 $\pm$ 0.003	0.001 $\pm$ 0.001	0.946	2.29e-15*
COM Work Rate (neg)	$-0.027\pm 0.003$	$-0.001\pm 0.001$	0.940	4.52e-14*
Summed Joint Work Rate (pos)	0.066 $\pm$ 0.006	$-0.000\pm 0.002$	0.962	1.11e-16*
Summed Joint Work Rate (neg)	$-0.053\pm 0.006$	$-0.001\pm 0.002$	0.940	2.11e-14*
Collision	$-0.174\pm 0.109$	$-0.001\pm 0.002$	0.896	4.51e-03*
Rebound	$-0.015\pm 0.114$	0.003 $\pm$ 0.001	0.704	7.76e-01
Preload	$-0.383\pm 0.178$	$-0.007\pm 0.003$	0.889	5.27e-04*
Push-off	0.507 $\pm$ 0.141	0.008 $\pm$ 0.005	0.966	4.60e-06*