Table 2. Onset times, duration of sensory and motor blocks.

	R25 (n = 23)	MR (n = 25)	R375 (n = 22)	P value
Onset time of motor block (min)	10.7±1.8	10.8±1.8	8.6±1.1 *	0.001
Onset time of sensory block (min)	8.5±1.7	8.4±1.7	6.4±1.0 *	0.001
Duration of motor block (min)	298.7±29.9	312.8±26.5	374.5±26.0 *	0.001
Duration of sensory block (min)	524.3±47.7	612.4±42.6 †	640.9±43.9 †	0.001

Values were expressed as mean ± SD.

R25: Perineural 0.25% ropivacaine with 15ml volume; MR: Perineural 200mg MgSO4 plus 0.25% ropivacaine with 15ml volume; R375: Perineural 0.375% ropivacaine with 15ml volume.

* P<0.01 indicates a significant difference in comparison to Group R25 and Group MR.

† P<0.01 indicates a significant difference in comparison to Group R25.