RESULTS	Post-hoc tests showed that the TENS group had significantly greater VT than both the placebo [ median difference 0.30 microm , 95 % confidence interval ( CI ) -0.05 to 0.66 ] and control ( 0.51 microm , 95 % CI 0.05 to 0.97 ) groups at 20 minutes , and significantly greater VT than the control group ( 0.69 microm , 95 % CI 0.20 to 1.17 ) at 30 minutes ( all p < 0.008 ) .\