Specific Contribution of the Transversus Abdominis for Postural Control Against Perturbation Caused by Kinesthetic Illusion.

Functional independence of the transversus abdominis (TrA) from other trunk muscles for postural control is still unclear. This study aimed to clarify the specific function of the TrA to control standing posture by vibratory stimulation of the triceps surae. Fifteen men participated in this study. Muscle activity of the TrA, internal oblique, lumbar multifidus, gluteus maximus, rectus femoris, biceps femoris, gastrocnemius, and tibialis anterior was measured using fine-wire and surface electrodes. Participants were asked to maintain a quiet standing posture with and without vibration of the triceps surae, which induced a kinesthetic illusion and the concomitant backward sway of the body. The muscle activity of each muscle for 10 s was extracted with and without vibration. The muscle activity levels were compared between the conditions by a paired t-test or Wilcoxon signed-rank test. The activity of the TrA and rectus femoris was increased, whereas the internal oblique showed no change as a result of the induced kinesthetic illusion. In addition, the activity of the multifidus and biceps femoris was decreased. The TrA and rectus femoris could contribute to control the backward sway of the body. Furthermore, the TrA may have functional independence from the internal oblique during standing postural control. These results warrant further study in patients with low back pain.

Local vibration induces changes in spinal and corticospinal excitability in vibrated and antagonist muscles.

Local vibration (LV) applied over the muscle tendon constitutes a powerful stimulus to activate the muscle spindle primary (Ia) afferents that project to the spinal level and are conveyed to the cortical level. This study aimed to identify the neuromuscular changes induced by a 30-min LV-inducing illusions of hand extension on the vibrated flexor carpi radialis (FCR) and the antagonist extensor carpi radialis (ECR) muscles. We studied the change of the maximal voluntary isometric contraction (MVIC, experiment 1) for carpal flexion and extension, motor-evoked potentials (MEPs, experiment 2), cervicomedullary motor-evoked potentials (CMEPs, experiment 2), and Hoffmann's reflex (H-reflex, experiment 3) for both muscles at rest. Measurements were performed before (PRE) and at 0, 30, and 60 min after LV protocol. A lasting decrease in strength was only observed for the vibrated muscle. The reduction in CMEPs observed for both muscles seems to support a decrease in alpha motoneurons excitability. In contrast, a slight decrease in MEPs responses was observed only for the vibrated muscle. The MEP/CMEP ratio increase suggested greater cortical excitability after LV for both muscles. In addition, the H-reflex largely decreased for the vibrated and the antagonist muscles. The decrease in the H/CMEP ratio for the vibrated muscle supported both pre- and postsynaptic causes of the decrease in the H-reflex. Finally, LV-inducing illusions of movement reduced alpha motoneurons excitability for both muscles with a concomitant increase in cortical excitability.NEW & NOTEWORTHY Spinal disturbances confound the interpretation of excitability changes in motor areas and compromise the conclusions reached by previous studies using only a corticospinal marker for both vibrated and antagonist muscles. The time course recovery suggests that the H-reflex perturbations for the vibrated muscle do not only depend on changes in alpha motoneurons excitability. Local vibration induces neuromuscular changes in both vibrated and antagonist muscles at the spinal and cortical levels.

Comparison of the immediate effects of plantar vibration of both feet with the plantar vibration of the affected foot on balance in patients with stroke: Preliminary findings.

OBJECTIVE: Plantar vibration is one of the strategies to enhance balance in stroke patients. This study compared the effects of the plantar vibration of both feet and the plantar vibration of the most affected side in patients with stroke. METHODS: This study was a single-blind clinical trial. Post-stroke patients with balance impairment were enrolled in the study and underwent two treatment sessions with a one-week interval. They received both feet's plantar vibration in one session and plantar vibration of the most affected side in the other session (frequency 100 Hz, 5 min). Mini-BESTest, Modified Modified Ashworth Scale (MMAS), and Semmes-Weinstein monofilament examination (SWME) were used to evaluate balance, spasticity, and plantar sensation, before and after the treatment sessions. RESULTS: Ten patients with a mean age of 52.9 (SD = 5.48) years were enrolled in the study. Mini-BESTest scores of balance and plantar flexor muscle spasticity were significantly improved after both feet plantar vibration and plantar vibration of the more affected side. There was no significant difference between the effectiveness of both sides plantar vibration and the most affected side plantar vibration. There were no significant improvements in SWME sensory scores after plantar vibration of either both sides or the most affected side. CONCLUSION: Plantar vibration of both sides had no additional benefits in this group of patients with chronic stroke. Plantar vibration of more affected side can be used for improving balance and plantar flexor spasticity post-stroke. The Plantar vibration had no effects on the affected foot sensibility.

Effects of prolonged local vibration superimposed to muscle contraction on motoneuronal and cortical excitability.

Introduction: Acute effects of prolonged local vibration (LV) at the central nervous system level have been well investigated demonstrating an altered motoneuronal excitability with a concomitant increase in cortical excitability. While applying LV during isometric voluntary contraction is thought to optimize the effects of LV, this has never been addressed considering the acute changes in central nervous system excitability. Materials and Methods: In the present study, nineteen healthy participants were engaged in four randomized sessions. LV was applied for 30 min to the relaxed flexor carpi radialis muscle (VIBRELAXED) or during wrist flexions (i.e. intermittent contractions at 10% of the maximal voluntary contraction: 15 s ON and 15 s OFF; VIBCONTRACT). A control condition and a condition where participants only performed repeated low-contractions at 10% maximal force (CONTRACT) were also performed. For each condition, motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation and cervicomedullary evoked potentials (CMEPs) elicited by corticospinal tract electrical stimulation were measured before (PRE) and immediately after prolonged LV (POST) to investigate motoneuronal and corticospinal excitability, respectively. We further calculated the MEP/CMEP ratio as a proxy of cortical excitability. Results: No changes were observed in the control nor CONTRACT condition. At POST, CMEP decreased similarly in VIBRELAXED (-32% ± 42%, p < .001) and VIBCONTRACT (-41% ± 32%, p < .001). MEP/CMEP increased by 110% ± 140% (p = .01) for VIBRELAXED and by 120% ± 208% (p = .02) for VIBCONTRACT without differences between those conditions. Discussion: Our results suggest that LV to the flexor carpi radialis muscle, either relaxed or contracted, acutely decreases motoneuronal excitability and induces some priming of cortical excitability.

Acute effects of quadriceps muscle versus tendon prolonged local vibration on force production capacities and central nervous system excitability.

PURPOSE: The present study aimed to directly compare the effects of 30 min muscle (VIBmuscle) vs. tendon (VIBtendon) local vibration (LV) to the quadriceps on maximal voluntary isometric contraction (MVIC) and rate of torque development (RTD) as well as on central nervous system excitability (i.e. motoneuron and cortical excitability). METHODS: Before (PRE) and immediately after (POST) LV applied to the quadriceps muscle or its tendon, we investigated MVIC and RTD (STUDY #1; n = 20) or vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) electromyography responses to thoracic electrical stimulation (TMEPs; motoneuron excitability) and transcranial magnetic stimulation (MEPs; corticospinal excitability) (STUDY #2; n = 17). MEP/TMEP ratios were further calculated to quantify changes in cortical excitability. RESULTS: MVIC decreased at POST (P = 0.017) without any difference between VIBtendon and VIBmuscle, while RTD decreased for VIBtendon (P = 0.013) but not VIBmuscle. TMEP amplitudes were significantly decreased for all muscles (P = 0.014, P < 0.001 and P = 0.004 for VL, VM and RF, respectively) for both LV sites. While no changes were observed for MEP amplitude, MEP/TMEP ratios increased at POST for VM and RF muscles (P = 0.009 and P = 0.013, respectively) for both VIBtendon and VIBmuscle. CONCLUSION: The present results suggest that prolonged muscle and tendon LV are similarly effective in modulating central nervous system excitability and decreasing maximal force. Yet, altered explosive performance after tendon but not muscle LV suggests greater neural alterations when tendons are vibrated.

Effect of plantar vibration on static and dynamic balance in stroke patients: a randomised controlled study.

OBJECTIVE: To investigate the effects of local vibration applied to the plantar region of the foot on static and dynamic balance in stroke patients. DESIGN: Randomised, controlled trial. SETTING: Inpatient. PARTICIPANTS: Thirty patients with stroke were randomised equally to the vibration and control groups. INTERVENTION: The control group underwent conventional physical therapy (CPT) for 4 weeks. The vibration group underwent local vibration therapy at a frequency of 80Hz and CPT for 4 weeks. OUTCOME MEASURES: The primary outcome measure was the Overall Stability Index (OSI). The secondary outcome measures were: the Anteroposterior Stability Index, Mediolateral Stability Index, fall risk, Berg Balance Scale, Functional Reach Test (FRT), and Timed Up and Go Test (TUG) to assess balance; the Trunk Impairment Scale to measure trunk function; and the 10-m Walk Test (10MWT) to measure walking speed. RESULTS: Participants receiving plantar vibration experienced greater improvements in static and dynamic balance assessments compared with participants in the control group. The mean change in OSI score between baseline and 4 weeks was 0.8 [standard deviation (SD) 0.8] for the vibration group and 0.02 (SD 0.6) for the control group [mean difference 0.4, 95% confidence interval (CI) 0.1 to 0.7]. The median change in fall risk score was 0.7 [interquartile range (IQR) 0.4 to 1.4] for the vibration group and 0.1 (IQR -0.1 to 0.6) for the control group (median difference 0.5, 95% CI 0.2 to 0.7). The median change in TUG time was 4 (IQR 1 to 7) seconds for the vibration group and 4 (IQR 0 to 2) seconds for the control group (median difference 2.5, 95% CI 1.5 to 3.5). CONCLUSION: These findings suggest that plantar vibration is useful in stroke patients. Plantar vibration can be applied to support CPT. GOV REGISTRATION NUMBER: NCT03784768.

Local vibration therapy promotes the recovery of nerve function in rats with sciatic nerve injury.

OBJECTIVE: It has been reported that local vibration therapy can benefit recovery after peripheral nerve injury, but the optimized parameters and effective mechanism were unclear. In the present study, we investigated the effect of local vibration therapy of different amplitudes on the recovery of nerve function in rats with sciatic nerve injury (SNI). METHODS: Adult male Sprague-Dawley rats were subjected to SNI and then randomly divided into 5 groups: sham group, SNI group, SNI + A-1 mm group, SNI + A-2 mm group, and SNI + A-4 mm group (A refers to the amplitude; n = 10 per group). Starting on the 7th day after model initiation, local vibration therapy was given for 21 consecutive days with a frequency of 10 Hz and an amplitude of 1, 2 or 4 mm for 5 min. The sciatic function index (SFI) was assessed before surgery and on the 7th, 14th, 21st and 28th days after surgery. Tissues were harvested on the 28th day after surgery for morphological, immunofluorescence and Western blot analysis. RESULTS: Compared with the SNI group, on the 28th day after surgery, the SFIs of the treatment groups were increased; the difference in the SNI + A-2 mm group was the most obvious (95% confidence interval [CI]: [5.86, 27.09], P < 0.001), and the cross-sectional areas of myocytes in all of the treatment groups were improved. The G-ratios in the SNI + A-1 mm group and SNI + A-2 mm group were reduced significantly (95% CI: [-0.12, -0.02], P = 0.007; 95% CI: [-0.15, -0.06], P < 0.001). In addition, the expressions of S100 and nerve growth factor proteins in the treatment groups were increased; the phosphorylation expressions of ERK1/2 protein in the SNI + A-2 mm group and SNI + A-4 mm group were upregulated (95% CI: [0.03, 0.96], P = 0.038; 95% CI: [0.01, 0.94], P = 0.047, respectively), and the phosphorylation expression of Akt in the SNI + A-1 mm group was upregulated (95% CI: [0.11, 2.07], P = 0.031). CONCLUSION: Local vibration therapy, especially with medium amplitude, was able to promote the recovery of nerve function in rats with SNI; this result was linked to the proliferation of Schwann cells and the activation of the ERK1/2 and Akt signaling pathways.

Effectiveness of Two Different Methods on the Perceived Pain and Satisfaction During Intramuscular Antibiotic Injection: ShotBlocker and Local Vibration.

In this study aimed to examine the effectiveness of ShotBlocker and local vibration on the perceived pain and satisfaction during intramuscular antibiotic injection. The sample of the randomized controlled experimental study consisted of 100 patients (32 in vibration group, 35 in ShotBlocker group, 33 in control group) who applied to the adult emergency clinic for antibiotic (amoxicillin/cefuroxime sodium) injection between April and May 2021. The study data were collected using the Structured Information Form, VAS for Pain and VAS for Satisfaction. CONSORT statement was followed for reporting. After the intramuscular antibiotic injection, a significant difference was found between the groups in terms of the mean scores of VAS for Pain and VAS for Injection Satisfaction (p < .001). It was determined that local vibration application was more effective in reducing the pain and in increasing satisfaction that occurs during intramuscular antibiotic injection according to ShotBlocker and control groups.

Local vibration training improves the recovery of quadriceps strength in early rehabilitation after anterior cruciate ligament reconstruction: A feasibility randomised controlled trial.

BACKGROUND: After anterior cruciate ligament reconstruction (ACLR), quadriceps strength must be maximised as early as possible. OBJECTIVES: We tested whether local vibration training (LVT) during the early post-ACLR period (i.e., ∼10 weeks) could improve strength recovery. METHODS: This was a multicentric, open, parallel-group, randomised controlled trial. Thirty individuals attending ACLR were randomised by use of a dedicated Web application to 2 groups: vibration (standardised rehabilitation plus LVT, n=16) or control (standardised rehabilitation alone, n=14). Experimenters, physiotherapists and participants were not blinded. Both groups received 24 sessions of standardised rehabilitation over ∼10 weeks. In addition, the vibration group received 1 hour of vibration applied to the relaxed quadriceps of the injured leg at the end of each rehabilitation session. The primary outcome - maximal isometric strength of both injured and non-injured legs (i.e., allowing for limb asymmetry measurement) - was evaluated before ACLR (PRE) and after the 10-week rehabilitation (POST). RESULTS: Seven participants were lost to follow-up, so data for 23 participants were used in the complete-case analysis. For the injured leg, the mean (SD) decrease in maximal strength from PRE to POST was significantly lower for the vibration than control group (n=11, -16% [10] vs. n=12, -30% [11]; P=0.0045, Cohen's d effect size=1.33). Mean PRE-POST change in limb symmetry was lower for the vibration than control group (-19% [11] vs. -29% [13]) but not significantly (P=0.051, Cohen's d effect size=0.85). CONCLUSION: LVT improved strength recovery after ACLR. This feasibility study suggests that LVT applied to relaxed muscles is a promising modality of vibration therapy that could be implemented early in ACLR. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02929004.

Effects of local vibration and extracorporeal shock wave therapy on triceps spasticity and the walking ability of hemiplegic stroke survivors / 中华物理医学与康复杂志

Objective:To compare the effect of local vibration and extracorporeal shock wave therapy (ESWT) on triceps spasticity and the walking ability of hemiplegic stroke survivors.Methods:Sixty-nine stroke survivors with hemiplegia were randomly divided into a control group, a vibration group and an ESWT group. The control group received 60 minutes of conventional Bobath rehabilitation treatment and motor relearning from Monday to Saturday for 4 weeks. For the vibration and ESWT groups, 10 minutes of that traditional therapy were replaced by either local vibration or extracorporeal shock wave treatment every Tuesday, Wednesday and Saturday. Before and after the treatment, the three groups were evaluated using the Comprehensive Spasticity Scale (CSS) and in terms of passive joint range of motion (PROM), ankle plantar flexion angle, 10m maximum walking speed, stride frequency, and stride length.Results:After the intervention the average CSS, PROM, and ankle plantar flexion angle were significantly better for all three groups than before the treatment. At that point the ESWT group′s averages were significantly better than those of the vibration group, and the vibration group′s averages were significantly superior to those of the control group. Walking speed, stride frequency and stride length had also improved significantly in all three groups, with those in the vibration and ESWT groups significantly outperforming the control group. There was no significant difference between the vibration and ESWT groups in terms of walking ability.Conclusions:Both local vibration and extracorporeal shock wave therapy improve triceps spasticity and the walking ability of hemiplegic stroke survivors. Shock waves are more effective for improving spasticity, but there is no significant difference between the therapies in terms of improving walking ability.

Local vibration therapy promotes the recovery of nerve function in rats with sciatic nerve injury / 中西医结合学报

OBJECTIVE@#It has been reported that local vibration therapy can benefit recovery after peripheral nerve injury, but the optimized parameters and effective mechanism were unclear. In the present study, we investigated the effect of local vibration therapy of different amplitudes on the recovery of nerve function in rats with sciatic nerve injury (SNI).@*METHODS@#Adult male Sprague-Dawley rats were subjected to SNI and then randomly divided into 5 groups: sham group, SNI group, SNI + A-1 mm group, SNI + A-2 mm group, and SNI + A-4 mm group (A refers to the amplitude; n = 10 per group). Starting on the 7th day after model initiation, local vibration therapy was given for 21 consecutive days with a frequency of 10 Hz and an amplitude of 1, 2 or 4 mm for 5 min. The sciatic function index (SFI) was assessed before surgery and on the 7th, 14th, 21st and 28th days after surgery. Tissues were harvested on the 28th day after surgery for morphological, immunofluorescence and Western blot analysis.@*RESULTS@#Compared with the SNI group, on the 28th day after surgery, the SFIs of the treatment groups were increased; the difference in the SNI + A-2 mm group was the most obvious (95% confidence interval [CI]: [5.86, 27.09], P < 0.001), and the cross-sectional areas of myocytes in all of the treatment groups were improved. The G-ratios in the SNI + A-1 mm group and SNI + A-2 mm group were reduced significantly (95% CI: [-0.12, -0.02], P = 0.007; 95% CI: [-0.15, -0.06], P < 0.001). In addition, the expressions of S100 and nerve growth factor proteins in the treatment groups were increased; the phosphorylation expressions of ERK1/2 protein in the SNI + A-2 mm group and SNI + A-4 mm group were upregulated (95% CI: [0.03, 0.96], P = 0.038; 95% CI: [0.01, 0.94], P = 0.047, respectively), and the phosphorylation expression of Akt in the SNI + A-1 mm group was upregulated (95% CI: [0.11, 2.07], P = 0.031).@*CONCLUSION@#Local vibration therapy, especially with medium amplitude, was able to promote the recovery of nerve function in rats with SNI; this result was linked to the proliferation of Schwann cells and the activation of the ERK1/2 and Akt signaling pathways.

Metabolomics study of rat tail vibration model / 环境与职业医学

Background The metabolites and metabolic pathways of hand-arm vibration syndrome have not yet been elucidated. Objective To investigate the effect of local vibration on endogenous metabolites in rat serum by metabolomic analysis, to preliminarily explore the potential metabolic pathway of endogenous metabolites, so as to provide evidence for further research on the mechanism of hand-arm vibration syndrome. Methods Thirty-two SPF male SD rats, (211.3±11.1) g, 7−8 weeks of age, were selected and randomly divided into three groups: control group (14 rats, without vibration), 7 d vibration group (9 rats, continuously vibration for 7 d), and 14 d vibration group (9 rats, continuous vibration for 14 d). The vibration rats were vibrated every day for 4 h, the frequency weighted acceleration was 4.9 m·s−2, the vibration frequency was 125 Hz, and the vibration direction was one-way vertical vibration. The control group had the same conditions except not contacting vibration. After the vibration exposure, the blood samples taken from the abnormal aorta of rats were collected, and the changes of rat serum metabolome were analyzed by ultra-performance liquid chromatography-tandem time-of-flight mass spectrometry. Principal components analysis (PCA) was used to explore changes in rat serum metabolic profile, and orthogonal partial least squares-discriminant analysis (OPLS-DA) was used to screen out differential metabolites. Combined with online databases, a metabolic pathway enrichment analysis of differential metabolites was performed. Results The PCA analysis showed that compared with the control group, the rat serum metabolic profiles in the 7 d group and the 14 d group were clearly differentiated, and the rat serum metabolic profiles in the 7 d group and the 14 d group partially overlapped. The OPLS-DA analysis showed significant differences between groups. The main parameters were: model interpretation rate R2Y=0.914, model predictive ability Q2=0.58. The OPLS-DA analysis screened out 26 and 119 differential metabolites from the 7 d group and the 14 d group respectively, and there were 24 common differential metabolites between the 7 d group and the 14 d group. The metabolomic pathway analysis showed that local vibration-induced changes in rat serum metabolism were mainly related to arachidonic acid metabolism in the 14 d group, among which the metabolites with significant effects were arachidonic acid, prostaglandin E2, and prostaglandin D2. Conclusion Local vibration could affect the normal metabolism in rats, and the metabolic pathway with significant influence is arachidonic acid metabolism after a 14 d exposure and the involved metabolites are arachidonic acid, prostaglandin E2, and prostaglandin D2.

Local plantar vibration for the treatment of diabetic neuropathy: a case report.

PURPOSE: One of the most common and debilitating complications of diabetes is peripheral neuropathy. Physical modalities such as whole-body vibration are used to treat diabetic peripheral neuropathy (DPN), but there are limted studies on the effectiveness of local vibration for the treatment of PDN. In this study, we aimed to evaluate the effectiveness of local vibration in treating a patient with DPN. METHODS: The local vibration was applied on the plantar side of both feet. The patient received 10 min of local vibration with 62.5 Hz frequency for five sessions. We used brief BESTest for balance evaluation, Numerical Pain Rating Scale (NPRS) for pain assessment, monofilament examination score for protective sensation evaluation, vibration threshold, and skin temperature to evaluate the effects of local vibration, which were measured before the treatment, after one session  of treatment, and after 5th session of treatment. RESULTS: There was a 62.5% reduction in pain severity after five sessions of treatment. Vibration threshold of both patient's feet and protective sensation of right foot returned to normal after treatment. Skin temperature was increased in all evaluated points of both patient's feet, brief BESTest score increased by six points after five treatment sessions, indicating improvements in the blood flow of feet and balance, respectively. CONCLUSIONS: Local plantar vibration was effective in improving the symptoms of DPN.

Local vibration induced vascular pathological structural changes and abnormal levels of vascular damage indicators.

BACKGROUND: The vascular component of the hand-arm-vibration syndrome (HAVS) is often characterized by vibration-induced white fingers (VWF). Active substances secreted by the vascular endothelial cells (VEC) maintain a dynamic balance but damage to the blood vessels may occur when the equilibrium is altered, thus forming an important pathological basis for VWF. This study was aimed at investigating vascular damage indicators as a basis for an early detection of disorders caused by vibration, using the rat tail model. METHODS AND RESULTS: Experiments were conducted using a control group of rats not exposed to vibration while two exposed groups having different exposure durations of 7 and 14 days were randomly formed. Following exposure, the structural changes of tail tissue samples in anesthetized rats were observed. Enzyme-linked immunosorbent assay (ELISA) was used for analyzing four vascular damage indicators myosin regulatory light chain (MLC2), endothelin-1 (ET-1), vinculin (VCL) and 5-hydroxytryptamine (5-HT) in tail blood samples. We found that both vascular smooth muscle and endothelial cells displayed changes in morphology characterized by vacuolization and swelling in the vibration-exposed group. The levels of vascular damage indicators were altered under the vibration. CONCLUSION: The degree of vascular pathology increased with the longer duration exposure. Furthermore, the levels of MLC2, ET-1 and 5-HT in rat plasma were associated with vascular injury caused by local vibration.

A Case of Nervus Laryngeus Superior Paresis Treated With Novafon Local Vibration Voice Therapy.

OBJECTIVE: The aim of the study is to present a case of chronic idiopathic superior laryngeal nerve paresis (SLNp) treated with a novel voice therapy approach called Novafon Local Vibration Voice Therapy (NLVVT). METHODS: Outcome measurements including acoustics, aerodynamics, and self-perception of voice handicap were acquired before intervention (i.e., NLVVT) and after intervention (i.e.,follow-up). The use of NLVVT was modified from previous reports of use in functional voice disorders for application to a neurological voice disorder (SLNp). RESULTS: The results showed that NLVVT had meaningful improvements in Voice Range Profile boundaries, an increase in speaking fundamental frequency, and improved acoustic indices of voice quality in a case of SLNp. The follow-up after NLVVT intervention revealed maintenance of the post-treatment improvements at a 1-month measurement interval. CONCLUSION: The NLVVT program may have potential to improve voice quality and vocal function in a case of SLNp. Further research is necessary to test a potential effectiveness for NLVVT applied to vocal fold immobility due to paresis in both larger numbers of patients and more well-designed, controlled experiments.

Effects of Preconditioning Local Vibrations on Subsequent Plantar Skin Blood Flow Response to Walking.

Weight-bearing exercise such as walking may increase risk of foot ulcers in people with diabetes mellitus (DM) because of plantar ischemia due to repetitive, high plantar pressure. Applications of local vibrations on plantar tissues as a preconditioning intervention before walking may reduce plantar tissue ischemia during walking. The objective of this study was to explore whether preconditioning local vibrations reduce reactive hyperemia after walking. A double-blind, repeated-measures, and crossover design was tested in 10 healthy participants without DM. The protocol included 10-minute baseline, 10-minute local vibrations (100 Hz or sham), 10-minute walking, and 10-minute recovery periods. The order of local vibrations was randomly assigned. Skin blood flow (SBF) was measured over the first metatarsal head during baseline and recovery periods. SBF responses were characterized as peak SBF, total SBF, and recovery time of reactive hyperemia. SBF was expressed as a ratio of recovery to baseline SBF to quantify the changes. Peak SBF in the vibration protocol (6.98 ± 0.87) was significantly lower than the sham control (9.26 ± 1.34, P < .01). Total SBF in the vibration protocol ([33.32 ± 7.98] × 103) was significantly lower than the sham control ([48.09 ± 8.9] × 103, P < .05). The recovery time in the vibration protocol (166.08 ± 32.71 seconds) was not significantly different from the sham control (223.53 ± 38.85 seconds, P = .1). Local vibrations at 100 Hz could reduce walking-induced hyperemic response on the first metatarsal head. Our finding indicates that preconditioning local vibrations could be a potential preventive intervention for people at risk for foot ulcers.

Immediate Effects of Local Vibration and Whole-body Vibration on Postural Control in Patients with Ataxia: an Assessor-Blind, Cross-over randomized trial.

Vibration interventions are used in neurorehabilitation to improve postural control in recent years. Little is known about the immediate effects of vibration interventions on postural control in patients with ataxia. The aim of this study is to investigate and compare the immediate effects of local vibration (LV) and whole-body vibration (WBV) on postural control in patients with ataxia. This study was designed as cross-over, single blind randomized clinical trial. Twenty-one patients with ataxia met the inclusion criteria. LV (frequency, 80 Hz; amplitude, 1 mm) and WBV (30 Hz, 2 mm) were applied to all patients. There was a 1-week washout time between interventions. Each patient was assessed 3 times: pre-intervention and 1 and 60 min post-intervention. The assessor was blinded to the interventions. Outcome measures were limits of stability (LoS), and postural sways (Bertec Balance Check Screener), gait parameters (GAITRite), and static balance (one-leg stance test). Twenty patients completed both interventions. The mean patient age was 39.43 ± 9.67 years. LV increased the left-LoS post-vibration (1 and 60 min post) more than WBV did (p ˂ 0.05). LV increased the LoS stability score and the base of support at 1 min post-vibration, while WBV decreased them (p ˂ 0.05). This study demonstrated different immediate effects of a single session of LV versus WBV and showed that LV has better effects on postural control in patients with ataxia. ClinicalTrials.gov. nr NCT04183647.

Effect of Different Local Vibration Frequencies on the Multiscale Regularity of Plantar Skin Blood Flow.

Local vibration has shown promise in improving skin blood flow (SBF). However, there is no consensus on the selection of the best vibration frequency. An important reason may be that previous studies utilized time- and frequency-domain parameters to characterize vibration-induced SBF responses. These parameters are unable to characterize the structural features of the SBF response to local vibrations, thus contributing to the inconsistent findings seen in vibration research. The objective of this study was to provide evidence that nonlinear dynamics of SBF responses would be an important aspect for assessing the effect of local vibration on SBF. Local vibrations at 100 Hz, 35 Hz, and 0 Hz (sham vibration) with an amplitude of 1 mm were randomly applied to the right first metatarsal head of 12 healthy participants for 10 min. SBF at the same site was measured for 10 min before and after local vibration. The degree of regularity of SBF was quantified using a multiscale sample entropy algorithm. The results showed that 100 Hz vibration significantly increased multiscale regularity of SBF but 35 Hz and 0 Hz (sham vibration) did not. The significant increase of regularity of SBF after 100 Hz vibration was mainly attributed to increased regularity of SBF oscillations within the frequency interval at 0.0095-0.15 Hz. These findings support the use of multiscale regularity to assess effectiveness of local vibration on improving skin blood flow.

Effects of graduated compression stockings, local vibration and their combination on popliteal venous blood velocity.

OBJECTIVES: The purpose of this pilot study was to examine and compare the effects of graduated compression stockings, local vibration, and combined graduated compression stockings and local vibration on popliteal venous blood velocity. METHOD: Twenty-four healthy subjects received four 15 min interventions (control, graduated compression stockings alone, local vibration alone, and combined graduated compression stockings and local vibration), while resting inactive in the prone position. Popliteal vein blood velocity was investigated before (PRE) and at the end (POST) of each intervention using Doppler ultrasound. RESULTS: At POST, peak velocity was reported to be 26.3 ± 53.5% (p < 0.05) greater for local vibration than control (CONT). Peak velocity was 46.2 ± 54.6% (p < 0.001) and 21.1 ± 37.6% (p < 0.01) higher for graduated compression stockings than CONT and local vibration, respectively. Graduated compression stockings + local vibration presented 64.1 ± 58.0% (p < 0.001), 38.4 ± 52.4% (p < 0.001) and 15.0 ± 31.6% (p < 0.05) greater values than CONT, local vibration and graduated compression stockings, respectively. CONCLUSIONS: This study demonstrated an increase in popliteal venous blood velocity after graduated compression stockings and local vibration application. Their combination provided the greatest effects.

Preliminary study of Novafon local vibration voice therapy for dysphonia treatment.

Background: The objective of this study was to explore the effectiveness of a five-week Novafon local vibration voice therapy (NLVVT) program for dysphonia treatment.Methods: Eleven dysphonic subjects participated in this specific program.Results: Treatment effects were assessed during (i.e. weekly) and after NLVVT. Large and significant treatment effects were revealed in acoustics (i.e. spectrography), and multiparametric indices (i.e. Acoustic Voice Quality Index (AVQI), and Dysphonia Severity Index (DSI)) during and after NLVVT (all p values < .01). Additionally, self-evaluation (i.e. Voice Handicap Index (VHI)) showed a significant improvement after NLVVT (p < .01). Gender independent voice range profile parameters (i.e. acoustics) only showed significant effects after treatment (p ≤ .01), but not during the treatment. Finally, aerodynamic measurement (i.e. phonation quotient) showed low treatment effects after NLVVT, which were not significant (p > .05).Conclusions: The preliminary results showed that NLVVT might be successful in voice treatment. Large treatment effects might be expected in AVQI, DSI, spectrography and VHI after using NLVVT. Other voice characteristics showed smaller treatment effects (i.e. voice range profile parameters) or no meaningful treatment effects (i.e. phonation quotient).