Table 2.

Powered lower limb multi-joint assisted exoskeletons.

Study	Year	Joint	App.	Weight & Load	Driver	Element	Subject	Speed
USA [46]	2004	$\mathrm{H}\prime$ $\mathrm{K}\prime$ $\mathrm{A}\prime$	EWB	W (41); L (34)	Hydraulic actuator drive	P (2.27)	$\mathrm{S}\prime$	1.3 m/s walking
USA [47]	——	$\mathrm{H}\prime$ $\mathrm{K}\prime$ $\mathrm{A}\prime$	EWB	W (14.52); L (68.04)	Power supply and on-board computer	P (0.1)	——	2.5 MPH walking 42 miles
[47]	——	$\mathrm{H}\prime$ $\mathrm{K}\prime$ $\mathrm{A}\prime$	EWB MA	W (22.68); L (68.04)	Power supply and on-board computer	——	——	Up 1000 feet
USA [48]	2006–2007	$\mathrm{H}\prime$ $\mathrm{K}\prime$ $\mathrm{A}\prime$	——	W (3.6); L (68.04–90.72); L (36.74);	Hydraulic actuator drive	——	——	2 MPH walking
China [49,50]	2007	$\mathrm{H}\prime$ $\mathrm{K}\prime$ $\mathrm{A}\prime$	EWB	W (21.2); L (30)	Air spring and motor drive	——	——	3.6 km/h walking 2 h
China [51,52,53]	2008	$\mathrm{H}\prime$ $\mathrm{K}\prime$ $\mathrm{A}\prime$	MA	W (25); L (35)	Hydraulic drive	——	——	12 h walking
Japan [59]	2009	$\mathrm{H}\prime$ $\mathrm{K}\prime$ $\mathrm{A}\prime$	EWB MA	W (23); L (70)	Motor drive	——	——	——
China [60]	2012	$\mathrm{H}\prime$ $\mathrm{K}\prime$ $\mathrm{A}\prime$	EWB	W (30); L (15)	Hydraulic drive	——	$1 \mathrm{M}\prime$	Stand upright
China [61,62]	2013	$\mathrm{H}\prime$ $\mathrm{K}\prime$	EWB	W (40); L (4)	Motor drive	P (0.4)	$1 \mathrm{M}\prime$	——
USA [65]	2016	$\mathrm{H}\prime$ $\mathrm{K}\prime$ $\mathrm{A}\prime$	MA	W (6.6); L (30% load for body weight)	Motor drive	——	7	1.5 m/s
China [63,64]	2016	$\mathrm{H}\prime$ $\mathrm{K}\prime$ $\mathrm{A}\prime$	EWB	W (16); L (45)	Hydraulic drive	——	——	4 km/h walking 1 h

App.: Application. $\mathrm{H}\prime$: Hip;$\mathrm{K}\prime$: Knee; $\mathrm{A}\prime$: Ankle; $\mathrm{F}\prime$: Foot; W: Weight (kg); L: Load (kg); $\mathrm{S}\prime$: Solider; $\mathrm{M}\prime$: Male; $\mathrm{F}\prime$: Female; HS: Heath subjects; SP: stroke patient; PSCI: patient with spinal cord injury; SM: simulation model; MA: Movement assistance; MR: Medical rehabilitation; ME: Motivation enhancement; EWB: Enhanced weight bearing; O: Orthosis; SC: Stiffness coefficient(N/mm); TS: Torsional stiffness (Nm/rad); P: Power (kW); ${\mathrm{MT}}_m$: Maximum torque of motor (Nm); ${\mathrm{MT}}_d$: Maximum torque of device (Nm); $\mathrm{P}\prime$: Normalized peak power (W/kg); P: Power (kW).