Table 3.

Linear regression between background EMG activity and stretch reflex amplitude for each perturbation direction

Group	Muscle	Perturbation Direction*	P Value	F-Statistic	Offset	Slope	r2 Value
Control	BRD	−X	<0.0001†	69.70	−1.59	3.77	0.59
	BI	−X	<0.0001†	65.74	−0.15	1.26	0.57
	TRILONG	−Y	<0.0001†	54.05	−2.04	2.06	0.52
	TRILAT	−Y	<0.0001†	138.26	−0.72	1.15	0.75
	AD	−Z	<0.0001†	61.83	−1.18	1.42	0.56
	MD	−X	<0.0001†	74.11	−0.83	0.95	0.60
	PD	−X	<0.0001†	43.92	−0.06	1.62	0.47
	PC	+Y	<0.0001†	44.98	3.10	2.28	0.48
Stroke	BRD	−X	0.22	1.54	—	—	0.03
	BI	−X	0.25	1.33	—	—	0.03
	TRILONG	−Y	<0.0001†	29.91	1.26	1.13	0.33
	TRILAT	−Y	<0.005†	8.86	1.48	0.43	0.13
	AD	−Z	<0.001†	16.27	0.42	0.46	0.22
	MD	−X	0.02†	6.09	1.44	0.31	0.10
	PD	−X	<0.001†	12.53	1.71	0.86	0.18
	PC	+Y	<0.0001†	17.62	5.74	1.01	0.23

^*Direction of perturbation was chosen for each muscle based on the maximum r² value produced by the linear regression model for the control group.

^†Significant regressions were defined at the 0.05 level.