We observed the effect of vibration parameters on lumbar spine under different vibration conditions using finite element analysis method in our laboratory. In this study, the CT-images of L1-L5 segments were obtained. All images were used to develop 3D geometrical model using the Mimics10.01 (Materialise, Belgium). Then it was modified using Geomagic Studio12.0 (Raindrop Geomagic Inc. USA). Finite element (FE) mesh model was generated by Hypermesh11.0 (Altair Engineering, Inc. USA) and Abaqus. Abaqus was used to calculate the stress distribution of L1-L5 under different vibration conditions. It was found that in a vibration cycle, tensile stress was occurred on lumbar vertebra mainly. Stress distributed evenly and stress concentration occurred on the left rear side of the upper endplate. The stress had no obvious changes under different frequencies, but the stress was higher when amplitude was greater. In conclusion, frequency and amplitude parameters have little effect on the stress distribution in vertebra. The stress magnitude is positively correlated with the amplitude.
Somatosensory vibration can stimulate somatosensory area of human body, and this stimulation is tranferred to somatosensory nerves, and influences the somatic cortex, which is on post-central gyrus and paracentral lobule posterior of cerebral cortex, so that it alters the functional status of brain. The aim of the present study was to investigate the neural mechanism of brain state induced by somatosensory vibration. Twelve subjects were involved in the 20 Hz vibration stimulation test. Linear and nonlinear methods, such as relative change of relative power (RRP), Lempel-Ziv complexity (LZC) and brain network based on cross mutual information (CMI), were applied to discuss the change of brain under somatosensory vibration stimulation. The experimental results showed the frequency following response (FFR) by RRP of spontaneous electroencephalogram (EEG) in 20 Hz vibration, and no obvious change by LZC. The information transmission among various cortical areas enhanced under 20 Hz vibration stimulation. Therefore, 20 Hz somatosensory vibration may be able to adjust the functional status of brain.
Objective To compare the effect of high-frequency chest wall oscillation (HFCWO) expectoration and mechanical vibration (MV) expectoration in elderly patients with pulmonary infection. Methods Thirty elderly patients with pulmonary infection were randomly divided into a HFCWO group and a MV group with 15 patients in each group. On the basis of routine treatment, the HFCWO group was treated with HFCWO vest to help expectoration, and the MV group underwent traditional mechanical vibration to help expectoration. The respiratory rate, peripheral oxygen saturation (SpO2), activities of daily living (ADL) score were measured before treatment (D1), 7 days (D7), and 14 days (D14) after treatment. Results Except ADL score had no difference between D7 and D14 in the MV group, there were significant differences in daily amount of sputum, respiratory rate, SpO2, ADL score between D1, D7, and D14 in both groups (P<0.05). There were no significant differences in daily amount of sputum between two groups on D1, D7, or D14. SpO2 and ADL score were significantly higher in the HFCWO group on D7 and D14 compared with the MV group (P<0.05). Conclusions Both high-frequency chest wall oscillation and mechanical vibration are effective in improving expectoration. The HFCWO vest is superior in improving blood oxygen and relieving shortness of breath than mechanical vibration expectoration.
Postmenopausal osteoporosis is a type of osteoporosis with high bone transformation rate, caused by a decrease of estrogen in the body, which is a systemic bone disease characterized by decreased bone mass and increased risk of fracture. In recent years, as a kind of non-pharmacologic treatment of osteoporosis, defined by whole-body vibration less than 1 g (g = 9.81 m/s2), low magnitude whole-body vibration is widely concerned, mainly because of its small side effects, simple operation and relative safety. Studies have shown that low magnitude whole-body vibration can improve bone strength, bone volume and bone density. But a lot of research found that, the therapeutic effects of low magnitude whole-body vibration are different depending on ages and hormone levels of subjects for animal models or human patients. There has been no definite vibration therapy can be applied to each subject so far. Studies of whole-body and cellular level suggest that low magnitude whole-body vibration stimulation is likely to be associated with changes of hormone levels and directed differentiation of stem cells. Based on the analysis of related literature in recent years, this paper made a review from vibration parameters, vibration effects and the mechanisms, to provide scientific basis and clinical guidance for the treatment of postmenopausal osteoporosis with low magnitude whole-body vibration.
This study investigated the early mechanical adaptability and osteogenic differentiation of mouse bone marrow mesenchymal stem cells (M-BMSCs) under micro-vibration stimulation (MVS). M-BMSCs were stimulated by MVS in vitro, cell proliferation, alkaline phosphatase (ALP) activity assay, and cytoskeleton were measured, and cell apoptosis was observed by flow cytometry. Early osteoblast-associated genes, runt-related transcription factor 2 (Runx2), Collagen Ⅰ (Col-Ⅰ) and ALP, were observed by RT-PCR and the activation of extracellular regulated protein kinases 1/2 (ERK1/2) was determined by Western blotting. The results showed that MVS had no significant effect on the proliferation of M-BMSCs. The early apoptosis was induced by mechanical stimulation (for one day), but the apoptosis was decreased after cyclic stimulation for 3 days. At the same time, MVS significantly accelerated the expression of F-actin protein in cytoskeleton, the synthesis of ALP and the ERK1/2 pathway, also up-regulated the expressions of Runx2, Col-Ⅰ and ALP genes. This study indicates that MVS could regulate cellular activity, alter early adaptive structure and finally promote the early osteogenic differentiation of M-BMSCs.
In order to reduce the impact caused by the contact between the foot and the ground when wearing the lower extremity exoskeleton under the condition of high load, this paper proposed an exoskeleton foot mechanism for improving the foot comfort, and optimized the key index of its influence on the comfort. Firstly, the physical model of foot mechanism was established based on the characteristics of foot stress in gait period, and then the mathematical model of vibration was abstracted. The correctness of the model was verified by the finite element analysis software ANSYS. Then, this paper analyzed the influence of vibration parameters on absolute transmissibility based on vibration mathematical model, and optimized vibration parameters with MATLAB genetic algorithm toolbox. Finally, this paper took white noise to simulate the road elevation as the vibration input, and used the visual simulation tool Simulink in MATLAB and the vibration equation to construct the acceleration simulation model, and then calculated the vibration weighted root mean square acceleration value of the foot. The results of this study show that this foot comfort mechanism can meet the comfort indexes of vibration absorption and plantar pressure, and this paper provides a relatively complete method for the design of exoskeleton foot mechanism, which has reference significance for the design of other exoskeleton foot and ankle joint rehabilitation mechanism.
The purpose of this study was to investigate the effect of low-magnitude vibration on osteogenesis of osteoblasts in ovariectomized rats with osteoporosis via estrogen receptor α(ERα). The mRNA expression of osteogenic markers were examined with qRT-PCR, based on which the optimal vibration parameter for promoting osteogenesis was determined (45 Hz × 0.9 g, g = 9.8 m/s2). Then we loaded the optimal vibration parameter on the osteoblasts of ovariectomized rats with osteoporosis. The protein expression of osteogenic markers and ERα were detected with Western blot; the distribution of ERα was examined with immunofluorescence technique. Finally, through inhibiting the expression of ERα with estrogen receptor inhibitor ICI182780, the protein and mRNA expression of osteogenic markers were examined. First, the results showed that low-magnitude vibration could promote the expression of osteogenic markers and ERα in osteoblasts of ovariectomized rats with osteoporosis (P < 0.05), and make ERα transfer to the nucleus. On the other hand, the results also showed that after inhibiting the expression of ERα in osteoblasts of ovariectomized rats with osteoporosis, the protein and mRNA expression of osteogenic marker were decreased (P < 0.05). In our study, low-magnitude vibration played an important role in the osteogenesis of osteoblasts in ovariectomized rats with osteoporosis through increasing the expression and causing translocation of ERα. Furthermore, it provides a theoretical basis for the application of low-magnitude vibration in the prevention and treatment of postmenopausal osteoporosis.
The human spine injury and various lumbar spine diseases caused by vibration have attracted extensive attention at home and abroad. To explore the biomechanical characteristics of different approaches for lumbar interbody fusion surgery combined with an interspinous internal fixator, device for intervertebral assisted motion (DIAM), finite element models of anterior lumbar interbody fusion (ALIF), transforaminal lumbar interbody fusion (TLIF) and lateral lumbar interbody fusion (LLIF) are created by simulating clinical operation based on a three-dimensional finite element model of normal human whole lumbar spine. The fusion level is at L4–L5, and the DIAM is implanted between spinous process of L4 and L5. Transient dynamic analysis is conducted on the ALIF, TLIF and LLIF models, respectively, to compute and compare their stress responses to an axial cyclic load. The results show that compared with those in ALIF and TILF models, contact forces between endplate and cage are higher in LLIF model, where the von-Mises stress in endplate and DIAM is lower. This implies that the LLIF have a better biomechanical performance under vibration. After bony fusion between vertebrae, the endplate and DIAM stresses for all the three surgical models are decreased. It is expected that this study can provide references for selection of surgical approaches in the fusion surgery and vibration protection for the postsurgical lumbar spine.
ObjectiveTo systematically review the efficacy of five types of rehabilitation exercises, including Baduanjin, aquatic exercise, Taijiquan, somatosensory exercise and whole body vibration training for the intervention of motor function in stroke patients. MethodsWeb of Science, PubMed, EMbase, The Cochrane Library, CNKI, CBM, CSJD and WanFang Data databases were electronically searched to collect randomized controlled trials (RCTs) of rehabilitation exercise interventions for motor function in stroke patients from inception to October 2020. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies; then, network meta-analysis was performed by using R and ADDIS software. ResultsA total of 50 RCTs involving 1 838 patients were included. The results of the meta-analysis showed that all five types of rehabilitation exercises were superior to conventional rehabilitation group in terms of balance in stroke patients (P<0.05), with the best ranking occupied by Baduanjin. In terms of lower limb strength, only the aquatic exercise was superior to conventional rehabilitation (P<0.05). In terms of walking function, somatic training and aquatic exercise were superior to conventional rehabilitation (P<0.05), with somatic exercises ranking first. ConclusionCurrent evidence shows that Baduanjin has an advantage in improving the balance, somatosensory interactive game exercise has an advantage in improving the walking capability and aquatic exercise has an advantage in improving the lower limb strength of stroke patients. Due to limited quality and quantity of the included studies, more high-quality studies are needed to verify the above conclusion.
Objective To explore the effect of respiratory training based on mechanical vibration-assisted sputum expulsion on arterial blood gases in patients with chronic obstructive pulmonary type 2 respiratory failure and clinical efficacy observation. Methods 105 patients with chronic obstructive pulmonary disease combined with type 2 respiratory failure who were hospitalized in our hospital from November 2019 to February 2023 were selected as study subjects. They were randomly numbered and divided into experimental and control groups according to the order of admission, and 3 patients withdrew from the study cohort due to their own reasons, and 51 cases each of the experimental and control groups were finally included. Patients in the control group were given conventional treatment and lung function exercise, while the experimental group was given respiratory training with mechanical vibration-assisted sputum expulsion. Lung function and blood gas analysis indexes were measured before and 2 weeks after treatment to evaluate the clinical efficacy and incidence of adverse events in the two groups. Results After the treatment, pulmonary function indexes such as PEF, FVC, FEV1 and FEV1/FVC, and blood gas analysis indexes such as PaO2, PaCO2 of the experimental group and daily sputum excretion improved significantly compared with those of the pre-treatment and control groups (P<0.05). The total clinical efficacy rate of the patients in the experimental group was significantly higher than that of the control group (P<0.05), and the incidence of adverse events was lower than that of the control group, but the difference was not statistically significant (P>0.05). Conclusion Respiratory training based on mechanical vibration-assisted sputum expectoration can help improve the lung function and blood gas level of patients with chronic obstructive pulmonary disease combined with type 2 respiratory failure, and it has a certain clinical value in promoting the rehabilitation and prognosis of patients.