Springs vs. motors: Ideal assistance in the lower limbs during walking at different speeds
Fig 5
Assistive device moments [first column], net muscle moments [second column], muscle activations in hip extensors [third column] and hip flexors [fourth column], and metabolic rates in hip extensors [fifth column] and hip flexors [sixth column] in unassisted conditions and with motor-based and spring-based assistance during slow (upper row), normal (middle row), and fast (lower row) walking speed. Mean values ± 1 standard deviation among all subjects and gait cycles are illustrated. Positive moment refers to hip extension, and negative to hip flexion. Change in hip extension (ΔτE) and hip flexion (ΔτF) moments, hip extensor (ΔaE) and hip flexor (ΔaF) muscle activations, and hip extensor () and hip flexor (
) muscles’ metabolic rates, shown as % of unassisted conditions, are presented.