Table 1.

Regression analysis results

	Formula	R2	P
(1)	ΔE = − 0.096 + 9.2 ⋅ Pavg − 0.49 ⋅ Ton ⋅ Pavg + 0.0055 ⋅ Ton 2 ⋅ Pavg	0.833	0.01
(2)	ΔE = 0.0088 + 9.1 ⋅ Pavg + 5 ⋅ Pavg 2 − 0.64 ⋅ Ton ⋅ Pavg + 0.0077 ⋅ Ton 2 ⋅ Pavg	0.990	<0.001
(3)	ΔE = − 10 + 10 ⋅ exp (0.89 ⋅ Pavg) Pavg − 0.62 ⋅ Ton ⋅ Pavg + 0.0075 ⋅ Ton 2 ⋅ Pavg	0.988	<0.001

Results of three different regressions that were used as potential candidates to result in a good fit for the effect of actuation timing and exoskeleton power on metabolic cost of exoskeleton walking with the resulting R² and P-values