Table 1.

Parameters derived using balance control model with PD neural control plus torque feedback.

Condition	Parameter	Mean (SD)	5%tile	25%tile	50%tile	75%tile	95%tile
1	Wprop	0.509 (0.079)	0.367	0.461	0.512	0.557	0.676
	Kp/mgh	1.51 (0.133)	1.31	1.42	1.50	1.56	1.79
	Kd/mgh	0.517 (0.067)	0.421	0.465	0.521	0.565	0.627
	Kf × 10,000	1.27 (0.46)	0.64	0.92	1.21	1.51	2.11
	Td	0.144 (0.015)	0.119	0.133	0.143	0.157	0.168
2	Wprop	0.396 (0.070)	0.298	0.351	0.390	0.442	0.534
	Kp/mgh	1.61 (0.144)	1.37	1.52	1.59	1.70	1.90
	Kd/mgh	0.542 (0.085)	0.406	0.473	0.554	0.598	0.670
	Kf × 10,000	1.17 (0.50)	0.48	0.77	1.13	1.52	2.21
	Td	0.120 (0.013)	0.098	0.111	0.117	0.128	0.145
3	Wprop	0.299 (0.057)	0.209	0.265	0.294	0.327	0.426
	Kp/mgh	1.61 (0.272)	1.34	1.41	1.56	1.71	2.51
	Kd/mgh	0.523 (0.072)	0.397	0.476	0.521	0.570	0.640
	Kf × 10,000	1.23 (0.56)	0.52	0.76	1.11	1.56	2.45
	Td	0.126 (0.023)	0.091	0.110	0.126	0.139	0.164
4	Wprop	0.207 (0.046)	0.137	0.168	0.204	0.238	0.297
	Kp/mgh	1.74 (0.341)	1.41	1.53	1.64	1.84	2.53
	Kd/mgh	0.543 (0.095)	0.334	0.475	0.548	0.612	0.705
	Kf × 10,000	1.35 (0.79)	0.32	0.68	1.29	1.83	3.06
	Td	0.092 (0.021)	0.056	0.076	0.094	0.104	0.129
5	Wvis	0.117 (0.050)	0.051	0.086	0.107	0.135	0.216
	Kp/mgh	1.24 (0.103)	1.12	1.19	1.22	1.28	1.53
	Kd/mgh	0.496 (0.045)	0.412	0.467	0.501	0.524	0.596
	Kf × 10,000	0.802 (0.894)	0.000	0.010	0.062	0.116	0.167
	Td	0.210 (0.025)	0.173	0.187	0.212	0.229	0.256
6	Wvis	0.055 (0.026)	0.025	0.038	0.048	0.069	0.121
	Kp/mgh	1,24 (0.113)	1.11	1.17	1.23	1.30	1.51
	Kd/mgh	0.494 (0.066)	0.397	0.444	0.496	0.526	0.606
	Kf × 10,000	0.88 (1.32)	0.00	0.11	0.47	1.06	5.11
	Td	0.202 (0.029)	0.146	0.178	0.211	0.226	0.240
7	Wprop + Wvis	0.556 (0.071)	0.435	0.511	0.553	0.590	0.689
	Kp/mgh	1.50 (0.137)	1.30	1.40	1.49	1.56	1.81
	Kd/mgh	0.482 (0.077)	0.354	0.423	0.468	0.546	0.610
	Kf × 10,000	1.19 (0.43)	0.46	0.92	1.17	1.38	1.98
	Td	0.132 (0.021)	0.090	0.122	0.133	0.148	0.160
8	Wprop + Wvis	0.431 (0.064)	0.345	0.377	0.424	0.497	0.531
	Kp/mgh	1.55 (0.120)	1.39	1.45	1.52	1.62	1.82
	Kd/mgh	0.492 (0.085)	0.342	0.435	0.486	0.563	0.623
	Kf × 10,000	1.05 (0.47)	0.34	0.73	1.00	1.47	1.92
	Td	0.104 (0.018)	0.072	0.093	0.104	0.121	0.127

Mean, standard deviation (SD) and distribution percentile values are based on 40 subjects except for Condition five where one subject's parameters were excluded. Units on K_p, K_d, K_f, and T_d are Nm/rad, Nms/rad, rad/(Nms), and s, respectively. K_p and K_d values for each subject were normalized by the subject's mgh (mass × gravity × center of mass height; units Nm/rad) value.