Table 7.

System response to horizontal perturbation (1 N applied at the T1 in anterior direction) for various q (muscle stiffness coefficient) values using linear perturbation analysis at deformed, stressed configurations (mm)

q	Translation, mm (With T12)				Translation, mm (Without T12)
	P=0 N	P=200 N (sides)			P=0 N				P=200 N	P=200 N
		No co-activity	2% co-activity	2–3% co-activity	No co-activity	2% co-activity	3% co-activity	2% co-activity + cubed muscle stresses	Sides	Front
2,500	2.46	0.589	-	-	0.82	-	-	-	0.48	0.50
1,500	4.61	-	-	-	0.95	-	-	-	-	-
1,000	11.63	-	-	-	-	-	-	-	-	-
500	-	-	-	-	-	-	-	-	-	-
250	*	1.49	0.33	0.26	4.51	0.79	0.37	0.38	0.93	0.70
150	-	-	-	-	*	-	-	-	1.26	0.72
100	-	-	-	-	-	-	-	-	-	-
75	-	-	-	-	-	-	-	-	-	-
50	-	-	-	-	-	1.97	-	1.94	-	-
40	-	6.02	-	1.43	-	-	-	-	3.46	1.15
35	-	-	-	-	-	3.41	2.04	3.84	-	-
30	-	8.94	2.60	1.92	-	*	2.57	5.29	4.50	1.31
20	-	*	4.04	2.93			*	*	*	1.69
15	-	-	*	3.98	-	-	-	-	-	2.00
5	-	-	-	*	-	-	-	-	-	*

^*System is unstable