Table 2.

Descriptive statistics of measures of motor performance foot load, stepping frequency, and knee amplitude during active and passive stepping at the three different levels of foot loading

		Passive				Active
	Load level	Mean	SD	Min	Max	Mean	SD	Min	Max
Foot load (%-BW)	0	6.69	1.44	5.36	9.00	9.34	3.06	6.47	16.16
	20	20.99	0.66	20.14	22.26	21.66	4.85	16.28	30.91
	40	35.48	4.29	31.40	41.97	34.11	2.73	30.70	37.39
Stepping frequency (Hz)	0	0.51	0.01	0.50	0.54	0.55	0.04	0.49	0.61
	20	0.51	0.00	0.50	0.51	0.54	0.03	0.51	0.59
	40	0.52	0.02	0.51	0.56	0.54	0.02	0.50	0.57
Knee amplitude (m)	0	0.14	0.00	0.14	0.15	0.16	0.03	0.10	0.19
	20	0.15	0.01	0.14	0.16	0.16	0.02	0.14	0.20
	40	0.15	0.01	0.14	0.16	0.15	0.02	0.13	0.18

Values for foot load are the maximal force values as measured by the force sensors at the foot fixation of the robot. n = 8, SD = standard deviation, min = minimum, max = maximum,  %-BW = percent body weight