Fig. 2.

Comparison between horizontal vibration exercise (HVE) and vertical vibration exercise (VVE) groups. (A) Visual analog scale, (B) Oswestry disability index, (C) lumbar flexor peak torque, (D) lumbar flexor average power, (E) lumbar extensor peak torque, (F) lumbar extensor average power, (G) transverse abdominis, (H) multifidus, (I) anteroposterior index, and (J) medio-lateral index. All variables except for muscle thickness were significantly changed according to time in each group; however, no variables with significant time-group interactions between the groups existed. All results were obtained using repeated-measures of ANOVA. Ho, horizontal vibration group; Ve, vertical vibration group; t0, assessment at baseline; t1, assessment at 6 weeks; t2, assessment at 12 weeks; t3, assessment performed after 4 weeks from the end of intervention. *p<0.05, a significant difference according to time in each group (solid line, difference in horizontal vibration exercise group; dotted line, difference in vertical vibration exercise group.