Effect Of Seated Whole Body Vibration Training On Walking Ability Of Elderly With Lower Limb Disability

Background and purposeThe aging process of the population in China is intensifying,and the aged people with disabilities are also accelerating.Due to the lack of proper physical exercise,the health conditions and daily living ability of the elderly disabled people are seriously affected,which brings heavy burden to families and society.Whole body vibration training(WBV)is a safe,easy and effective way for exercise and rehabilitation,which has been applied to different people and fields.However,most existing studies used standing position,and there are few studies with other special positions(such as seated position)for some special groups.Therefore,this study designed the Seated Whole Body Vibration Training(SWBVT)experiment for the elderly with lower limb disability according to the existing research results of the vibration training.First,the specific differencesof lower limbs activity functionbetween the lower extremity disabled and healthy elderly was compared,and thenanalyzed the correlation between selected measurements and walking ability for elderly subjects with lower limb disability.Finally,we explored the influence of SWBVT on walking ability and the different intervention time on the results based on 2 experiments with different intervention time,and also a decline period was set up between the two experiments in order to observe the duration of the SWBVT effect.This study tries to find a safe and effective way of exercise and rehabilitation for the elderly people with lower extremity disability,in order to improve their health conditions and self-reliance in daily life,also provides theoretical and data support and reference for further research on SWBVT.This study is divided into three parts.Methods:Part 1:20 elderly people with lower limb disability(9M,11 F,the level of limbs disability is four,which basically can achieve daily activities)and 20 healthy elderly people(10M,10F)as the research object,maximum knee flexion and extension strength(120� /s),static balance,Timed Up and Go Test(TUG),6 Minutes Walking Distance(6MWD),10 Meters Walking Time(10MWT)and daily physical activity status were measured and analyzed.Part 2:through the analysis to determine the walking speed is the key indicator of walking ability,according to the measurement results of part 1,analyzedthe correlation between 10 MWT and maximum knee flexion and extension muscle strength,static balance,TUG and 6MWD for disabled subjects.Part 3:after data analysis and validation,the disabled 20 subjects(part 1,9M and 11 F)were divided into 1 group to carry out 2 SWBVT experiments,and an8 weeks decline period was set up between the two experiments.The 1stexperiment lasted 8 weeks,the amplitude was 2mm,frequency was 6~9Hz,3 days per week,interval rest 1 day,and training for 9~15 minutes per day.Before(T1)and after(T2)the experiment,extensor and flexor peak torque of knee joint(relatively healthy,120 �/s),TUG,6MWD,10 MWT,static balance,reaction time and total body bone mineral density(BMD)and bone mineral content(BMC),daily physical activity status were measured and compared.Except the daily intervention time added to 20~30 minutes,vibration frequency,amplitude and intervention cycle in 2ndexperiment were all same to 1st.The 2nd data were labeled T3 and T4 before and after the experiment.Results:Part 1:maximum knee flexion and extension strength of disabled subjects was significantly lower than that of healthy subjects(p<0.05),TUG,6MWD and 10 MWT scores decreased significantly(p<0.05),6 of 7 static balance indicators with eyes open and close had obvious difference(p<0.05),the daily effective activity time,mild and moderate physical activity time,and daily walking steps were significantly lower than that of healthy subjects(p<0.05).Part 2:significant correlation between 10 MWT and maximum knee flexion(r=-0.491,p=0.028)and extension(r=-0.590,p=0.006)muscle strength,6MWD(r=-0.496,p=0.026);strong correlation with TUG(r=0.643,p=0.002);significant correlation between 6 and 5 in 7 indicators of static balance respectively with open and close eyes(p<0.05).Part 3:1)Results of 1st experimental(compared T1 and T2): knee flexion and extensor muscle strength had significant difference(p<0.05);TUG,6MWD and 10 MWT were very significant(p<0.01);the 7 indicators with eyes open of static balance were reduced after the experiment,but no significant difference(p>0.05);Length,Avg.v,and X Speed had significant difference(p<0.05),Y Speed very significant difference(p<0.01)with eyes close;a very significant difference between the simple reaction time and the selection reaction(p<0.01);no significant difference in BMD and BMC(p>0.05);no significant difference in the effective activity time before and after the treatment(p>0.05);significant difference in daily walking steps(p<0.05).2)Results of decline period(compared with T1 and T3): some indicators had increased or reduced,but no significant difference.3)Results of 2nd experiment(compared T4 and T3): knee flexion and extensor muscle strength,TUG,6MWD and 10 MWT were all very significant(p<0.01);Length decreased significantly(p<0.05),no significant difference in other indexes with eyes open;a significant difference in X Dev.(p< 0.05),Length,Avg.v,X Speed and Y Speed had very significant differences(p<0.01)with eyes close;very significant difference between the simple reaction time and the selection reaction(p<0.01);no significant difference in BMD and BMC(p>0.05);no significant difference in the effective activity time before and after the treatment(p>0.05);significant difference in daily walking steps(p<0.05).4)Results of thecomparison of 2 experiments(compared T2 and T4):TUG showed significant difference(p<0.05),some other indicators had some improvement,but showed no significant difference(p>0.05).Conclusion:1)Lower limbsactivity function is significantly lower than that of the healthy group,as reflected in the function decline of knee flexion and extension muscle strength,TUG,static balance ability,10 MWT and 6MWD.The main reason for this difference is the lack of physical activity time,especially the lack of moderate physical activity time thatcaused by disability in the lower limbs.2)The maximum knee flexion and extension strength,TUG,static balance and 6MWD are closely related to walking speed,which can be used to evaluate walking ability of disabled subjects.3)SWBVT can significantly improve the subjects' knee flexion and extension muscle strength,reaction speed,walking speed and walking endurance,also significantly improved walking balance and static balance ability with eyes close,thus significantly improved the walking ability;the improvement of these indicators led to a significant increase in the number of walking steps in the daily life,no obvious effect on static balance with eyes open,BMD and BMC as well as effective activity time.4)After 8 weeks' intermission,the intervention effect of the 1st experiment had fade away,indicating that the maintenance period of effect with 8 weeks of SWBVT on the indicators is no longer than 8 weeks.5)Pr olonged SWBVT had obvious improvement effect on walking balance.