Retrospective study of effect of whole-body vibration training on balance and walking function in stroke patients

BACKGROUND Dysfunction in stroke patients has been a problem that we committed to solve and explore.Physical therapy has some effect to regain strength,balance,and coordination.However,it is not a complete cure,so we are trying to find more effective treatments.AIM To observe the effect of whole-body vibration training(WVT)on the recovery of balance and walking function in stroke patients,which could provide us some useful evidence for planning rehabilitation.METHODS The clinical data of 130 stroke participants who underwent conventional rehabilitation treatment in our hospital from January 2019 to August 2020 were retrospectively analyzed.The participants were divided into whole-body vibration training(WVT)group and non-WVT(NWVT)group according to whether they were given WVT.In the WVT group,routine rehabilitation therapy was combined with WVT by the Galileo Med L Plus vibration trainer at a frequency of 20 Hz and a vibration amplitude of 0+ACY-plusmn+ADs-5.2 mm,and in the NWVT group,routine rehabilitation therapy only was provided.The treatment course of the two groups was 4 wk.Before and after treatment,the Berg balance scale(BBS),3 m timed up-and-go test(TUGT),the maximum walking speed test(MWS),and upper limb functional reaching(FR)test were performed.RESULTS After 4 wk training,in both groups,the BBS score and the FR distance respectively increased to a certain amount(WVT=46.08±3.41 vs NWVT=40.22±3.75;WVT=20.48±2.23 vs NWVT=16.60±2.82),with P<0.05.Furthermore,in the WVT group,both BBS score and FR distance(BBS:18.32±2.18;FR:10.00±0.92)increased more than that in the NWVT group(BBS:13.29±1.66;FR:6.16±0.95),with P<0.05.Meanwhile,in both groups,the TUGT and the MWS were improved after training(WVT=32.64±3.81 vs NWVT=39.56±3.68;WVT=12.73±2.26 vs NWVT=15.04±2.27,respectively),with P<0.05.The change in the WVT group(TUGT:17.49±1.88;MWS:6.79±0.81)was greater than that in the NWVT group(TUGT:10.76±1.42;MWS:4.84±0.58),with P<0.05.CONCLUSION The WVT could effectively improve the balance and walking function in stroke patients,which may be good for improving their quality of life.

The Progress of the Study on the Effect of Vibration Training on Muscle Strength Exercise

Vibration training is more and more extensively applied to the field of strength training. It, as a beneficial supplement to the traditional strength, is able to improve specific strength or the strength of weak positions, for the purpose of achieving the muscle strength development in an all-round way. In this paper, the anatomy, physiology, and biomechanics foundations for vibration training to increase muscle strength are mainly analyzed, and then the principle of vibration training to increase muscle strength is further expounded, and also the increase of muscle strength is discussed from the aspects such as vibration frequency, vibration amplitude, vibration posture, vibration intermittent time, and vibration mode, so as to clarify the domestic and foreign progress of the study on vibration training.

Seismic features of vibration induced by train

Based on schematically formulation of the vibrations induced by moving trains, this paper analyses the waveforms along the Datong-Qinhuangdao railroad in Northern China recorded in the suburban Huairou district of Beijing on March 8, 2003. It is illustrated that vibrations induced by train, except traditional recognized noises and interfer- ence effects, could be used as a seismic source to detect crustal structures with its advantage of abundant frequency spectrum, repeatability and no additional harm to the environment. It will bring lights to the traditional exploration seismology with the further studies of signal processing and interpretation methods, and related models and new observing systems.

Effects of vibration in desert area caused by moving trains

The ballast layer, filled with fine particles like blown sand, is one of the important problems of ballasted railway tracks in desert areas. Blown sand, as a contaminator of ballast layer, increases track stiffness and may cause serious damage to sleepers, pads, rails, and vehicles. In this paper, the effects of increasing track stiffness due to windy sands in the ballast layer and the train induced vibrations due to this phenomenon were studied. Based on field studies in a desert area in Iran, a two-dimensional finite/infinite element model for a railway track with plane strain condition was analyzed using the software ABAQUS, and the track vibrations were examined by changing the values of stiffness of ballast layer. Vibrations caused by the load of train at different distances from the cross-section of track were inves- tigated, and the values of vertical vibration displacement, velocity, and acceleration were calculated. Results show that acceleration values of vertical vibration increase with the increasing of ballast layer stiffness caused by the filling of sand, while the vertical vibration velocity of track and the induced ground displacement decrease. The farther the distance from the source of vibration, the less the displacement, velocity, and acceleration. In addition, the methods for reducing train-induced vibrations were introduced.

Analysis of the Dynamic Response of a Shield Tunnel in Soft Soil Under a Metro-Train Vibrating Load

This paper concerns the impact of an operating metro train on the structure of a shield tunnel lining and its soft foundation. An elastoplastic 3D dynamic finite difference model was established by using the FLAC3D numerical soft- ware. By fully considering the joints, the A-B-K segments and the soft stratum, the dynamic response of the shield tunnel buried in thick, soft soil under the vibrating load induced by a metro train was numerically simulated. The simulation result, for which the joint was considered, was compared with the result when the joint was not considered. The results show that an operating metro train induces a significant dynamic response in the structure of the lining of the shield tunnel and its soft foundation. The severe dynamic response zones of the lining structure are largely distributed in the range of the lower half of the segment-ring and the nearer to the bottom of the segment-ring, the more severe the response. Of two horizontally symmetric, corresponding places on the segment lining, the one near the joint is more severe in its dynamic response than that of the one far from the joint; the nearer the zone of the foundation soil to the lower half of the seg- ment-ring, the more severe the dynamic response. The maximum shear strain of the foundation soil takes place near the joint between two normal segments at the bottom. The dynamic response influenced by joints is more severe than the response not influenced by joints, showing that the non-joint assumption is somewhat impractical.

Seismic and vibration control of segmented isolation layer in underground structure-diaphragm wall system

In this paper,a seismic and vibration reduction measure of subway station is developed by setting a segmented isolation layer between the sidewall of structure and the diaphragm wall.The segmented isolation layer consists of a rigid layer and a flexible layer.The rigid layer is installed at the joint section between the structural sidewall and slab,and the flexible layer is installed at the remaining sections.A diaphragm wall-segmented isolation layer-subway station structure system is constructed.Seismic and vibration control performance of the diaphragm wall-segmented isolation layer-subway station structure system is evaluated by the detailed numerical analysis.Firstly,a three-dimensional nonlinear time-history analysis is carried out to study the seismic response of the station structure by considering the effect of different earthquake motions and stiffness of segmented isolation layer.Subsequently,the vibration response of site under training loading is also studied by considering the influence of different train velocities and stiffness of the segmented isolation layer.Numerical results demonstrate that the diaphragm wall-segmented isolation layer-subway station structure system can not only effectively reduce the lateral deformation of station structure,but also reduce the tensile damage of the roof slab.On the other hand,the developed reduction measure can also significantly reduce the vertical peak displacements of site under training loading.

Hybrid fiber Bragg grating sensor for vibration and temperature monitoring of a train bearing

We report a fiber Bragg grating（FBG）-based sensor for the simultaneous measurement of a train bearing’s vibration and temperature. A pre-stretched optical fiber with an FBG and a mass is designed for axial vibration sensing. Another multiplexed FBG is embedded in a selected copper-based alloy with a high thermal expansion to detect temperature. Experiments show that the sensor possesses a high resonant frequency of 970 Hz, an acceleration sensitivity of 27.28 pm/g, and a high temperature sensitivity of 35.165 pm/℃. A resonant excitation test is also carried out that demonstrates the robustness and reliability of the sensor.