Table 2.

Mean of four times measurements ± standard deviation of %MVC

		The amount of muscle activity (%MVC) [%]
Condition	Muscle	Subject 1	Subject 2	Subject 3	Subject 4	Subject 5	Average
Without headrest	Left	23.8 ± 2.09	31.0 ± 1.39	27.0 ± 0.39	30.6 ± 2.08	29.6 ± 3.28	28.41
	Right	23.9 ± 1.92	34.6 ± 1.64	28.4 ± 0.52	33.3 ± 3.05	21.1 ± 0.99	28.25
With headrest	Left	10.5 ± 0.46	17.5 ± 0.95	13.4 ± 0.67	13.8 ± 1.01	19.6 ± 1.32	14.97
	Right	13.2 ± 0.36	18.8 ± 0.87	13.2 ± 0.64	14.0 ± 0.74	15.5 ± 0.34	14.93