Powered ankle-foot orthoses: the effects of the assistance on healthy and impaired users while walking

Table 9 Comparison of the effects of different assistance magnitude on the user’s effort during loaded walking

Ref.	Load	Assistance magnitude		Metabolic cost w.r.t. U	Metabolic cost w.r.t. N
Lee, 2016 [23] ⋆	23 kg	double neg	10% of double pos	-11%	/
	(29% bodyweight)		20% of double pos	-11%
			30% of double pos	-15%
		double pos	same value for all neg conditions
Malcolm, 2017 [25] ⋆	23 kg	double neg	-0.015 W/kg	-11%	/
	(29% bodyweight)		-0.016 W/kg	-12%
			-0.027 W/kg	-11%
			-0.037 W/kg	-15%
		double pos	0.19 W/kg
Mooney, 2014 [47] ⋈	23 kg	double pos	0.27 W/kg	/	-8%
	(27% bodyweight)
		double neg	0 W/kg

The assistance magnitude is defined as the average power provided by the PAFO per stride. The effects on the metabolic cost of powered walking are reported with respect to the unpowered (U) or normal walking (N) condition. It should be noted that the amount of load as a percentage of the subjects’ bodyweight is comparable between different studies
Symbols (⋆,⋈) indicate studies performed by the same research group on similar actuation setups. Symbols are consistent between tables. In the works in which different experiments were performed (for example, different levels of assistance magnitude) the common information between the experiments (for example, same load) is reported only once

ISSN: 1743-0003