Immediate Effect Of Different Whole-body Vibration Methods On Balance Ability

Background: The ability to balance is the basis of ensuring that the human body can complete all kinds of physical activities.Whole body vibration training is a safe and effective way of exercise and rehabilitation,similar to "passive training",without severe muscle contraction,the training method is simple,At present,most studies on balance ability of whole body vibration training use standing position.In recent years,vibration beds have been introduced into the health care community,including decubitus vertical vibration beds and Whole Body Periodic Acceleration.Literature retrieval found that there were few studies on decubitus vibration,and the effect of decubitus vibration training on balance ability was not clear,so this study was conducted.Objective: The immediate effect of standing vertical vibration,decubitus vertical vibration and Whole Body Periodic Acceleration on balance ability were studied and compared.Methods: A total of 30 healthy male college students were recruited for this study.Each subject was pre-tested for static and dynamic indicators,and then randomly subjected to 5 interventions,namely,standing blank control（BODYGREEN I-VIB5050,standing without vibration）,decubitus blank control（BODYGREEN MU1,lying flat without vibration）,standing vertical vibration（BODYGREEN I-VIB5050,10 Hz,4mm）,decubitus vertical vibration（BODYGREEN MU1,10 Hz,2mm）,Whole Body Periodic Acceleration（BODYGREEN MB1,140 RPM,20mm）.The two blank controls were kept without vibration for 15 min,and the three vibration interventions were all continuously vibrated for 15min（15min is the time of one vibration suggested by the equipment manufacturer）.Static and dynamic homeostasis were measured immediately after each intervention and followed by a one-week washout period.All subjects received 5 different interventions.Static balance The Freestep plantar pressure tester made in Italy was used to test the subjects under four standing conditions（eyes open on both feet,eyes closed on both feet,eyes open on dominant side and eyes closed on dominant side）,and the indicators of center of gravity track,Sway length,Ellipse area,Delta X,Delta Y and average speed were collected.Dynamic Balance Dynamic posture stability testing were performed using the Biodex Balance System SD Balance tester.Overall Stability Index（OSI）,anterior and posterior stability index（APSI）,and medial and lateral stability index（MLSI）were collected for standing with eyes open on both feet and dominant side.Limits of Stability Testing was performed,and Overall Direction Control（ODC）and Time To Complete Trial（CTT）were collected.In addition,the Movement Assessment Tool was also used to test the balance of dominant Star Excursion Balance Test.Repeated measures one-way ANOVA was used to determine whether there were differences in balance ability between different interventions.LSD was used for post hoc analysis,and the statistical difference level was set at P<0.05.Results: 1.Static balance :（1）standing with eyes open on both feet,there was no significant difference between different intervention methods（P>0.05）;（2）standing with eyes closed on both feet,the ellipse area index of standing vertical vibration was significantly worse than that of pretest and decubial blank（P<0.05）.（3）dominant leg standing with eyes open,The decubitus vertical vibration was significantly better than that in the pretest and the two blank controls in terms of sway length and average speed（P<0.05）.The Delta X index of Whole Body Periodic Acceleration was significantly better than that in decubial blank and standing blank（P<0.05）.（4）dominant leg standing with eyes closed,the standing vertical vibration was significantly worse than that of the pretest,standing blank and decubial blank in terms of sway length and ellipse area（P<0.05）.In addition,there was no significant difference in each index between the two blank control groups compared with the pre-test.In all the indexes with significant differences,the decubitus vertical vibration and Whole Body Periodic Acceleration were better than those in standing vertical vibration（P<0.05）.There was no significant difference between decubitus vertical vibration and Whole Body Periodic Acceleration（P>0.05）.2.Dynamic balance:（1）Posture Stability Testing: the OSI and APSI indexes of decubitus vertical vibration and Whole Body Periodic Acceleration while standing on two feet were significantly better than those of pretest,standing blank and standing vertical vibration（P<0.05）;There was no significant difference between decubitus vertical vibration and Whole Body Periodic Acceleration（P>0.05）.Standing on the dominant side,Compared with pretest,standing blank,decubitus blank and standing vertical vibration,the OSI of decubitus vertical vibration and Whole Body Periodic Acceleration was significantly better（P<0.05）.There was no significant difference between decubitus vertical vibration and Whole Body Periodic Acceleration（P>0.05）.（2）Limit Of Stability Testing : the ODC of decubitus vertical vibration was significantly better than that of pretest,standing blank and standing vertical vibration（P<0.05）.（3）Star Excursion Balance Test:the comprehensive values of decubitus vertical vibration and Whole Body Periodic Acceleration were significantly better than those of pre-measurement,standing blank,decubitus blank and standing vertical vibration（P<0.05）.There was no significant difference（P>0.05）between decubitus vertical vibration and Whole Body Periodic Acceleration.The decubitus vertical vibration was significantly better in the forward and inward direction than that of pretest,standing blank and standing vertical vibration（P<0.05）.Whole Body Periodic Acceleration was significantly better than that in pretest,standing blank and standing vertical（P<0.05）.There was no significant difference in other directions（P>0.05）.Conclusions:1.A 15-minute standing vertical vibration（10HZ,4mm）damaged the immediate static balance ability,but had no effect on the dynamic balance ability;2.A 15-minute decubitus vertical vibration（10HZ,2mm）and Whole Body Periodic Acceleration（140RPM,20mm）can improve the immediate static and dynamic balance ability,but the decubitus vertical vibration can improve the immediate static and dynamic balance ability in more indicators than Whole Body Periodic Acceleration,so the decubitus vertical vibration can improve the immediate balance ability better.