The within-group comparison found a significant difference in elbow range of motion for the IG [ mean difference -15.4 , 95 % confidence interval ( CI ) -20.1 to -10.6 ; P = 0.01 ] , but not for the CG ( mean difference -4.9 , 95 % CI -11.8 to 2.0 ; P = 0.15 ) .