Effect of low-magnitude, variable-frequency vibration therapy on pain threshold levels and mobility in adults with moderate knee osteoarthritis-randomized controlled trial

BACKGROUND

Osteoarthritis (OA) is one of the most commonly recorded diseases in clinical practice. Vibration therapy has been suggested for the treatment of knee OA. The purpose of the study was to determine the impact of vibrations of variable frequency and low amplitude on pain perception and mobility in patients suffering from knee OA.

METHODS

Thirty-two participants were allocated into two groups - Group 1 (oscillatory cycloidal vibrotherapy-OCV) and Group 2-control (sham therapy). The participants were diagnosed with moderate degenerative changes in the knee (grade II based on the Kellgren-Lawrence (KL) Grading Scale). Subjects received 15 sessions of vibration therapy and sham therapy respectively. Pain, range of motion, and functional disability were assessed through Visual Analog Scale (VAS), Laitinen questionnaire, goniometer (ROM - range of motion), timed up and go test (TUG) and Knee Injury and Osteoarthritis Outcome Score (KOOS). Measurements were taken at baseline, after the last session and four weeks after the last session (follow up). T-test and U-Mann Whitney test compare baseline characteristics. The Wilcoxon and ANOVA tests compared mean VAS, Laitinen, ROM, TUG and KOOS. The significant P-value was less than 0.05.

RESULTS

After 3 weeks (15 sessions) of vibration therapy, reduced the sensation of pain and improved mobility was recorded. There was a more significant improvement in the vibration therapy group than the control group in pain alleviation on VAS scale (p < 0.001), on Laitinen scale (p < 0.001), knee ROMs flexions (p < 0.001) and TUG (p < 0.001) at the last session. KOOS score with pain indicator, symptoms, activities of daily living, function in sport and recreation and knee related quality of life improved more in the vibration therapy group than the control group. Effects maintained up to 4 weeks in vibration group. No adverse events were reported.

CONCLUSIONS

Our data demonstrated that the use of vibrations of variable frequency and low amplitude in patients with the knee OA is a safe and effective therapy. It is recommended to increase the number of treatments performed, primarily in patients with degeneration II° according to the KL classification.

TRIAL REGISTRATION

Prospectively registered on ANZCTR ( ACTRN12619000832178 ). Registered on 11 June 2019.

Vibration and current dataset of three-phase permanent magnet synchronous motors with stator faults

Permanent magnet synchronous motors (PMSM) are widely used in industry applications such as home appliances, manufacturing process, high-speed trains, and electric vehicles. Unexpected faults of PMSM are directly related to the significant losses in the engineered systems. The majority of motor faults are bearing fault (mechanical) and stator fault (electrical). This article reports vibration and driving current dataset of three-phase PMSM with three different motor powers under eight different severities of stator fault. PMSM conditions including normal, inter-coil short circuit fault, and inter-turn short circuit fault in three motors are demonstrated with different powers of 1.0 kW, 1.5 kW and 3.0 kW, respectively. The PMSMs are operated under the same torque load condition and rotating speed. Dataset is acquired using one integrated electronics piezo-electric (IEPE) based accelerometer and three current transformers (CT) with National Instruments (NI) data acquisition (DAQ) board under international organization for standardization standard (ISO 10816-1:1995). Established dataset can be used to verify newly developed state-of-the-art methods for PMSM stator fault diagnosis. Mendeley Data. DOI: 10.17632/rgn5brrgrn.5.

A neuromuscular human body model for lumbar injury risk analysis in a vibration loading environment

BACKGROUND AND OBJECTIVE

Long-term intensive exposure to whole-body vibration substantially increases the risk of low back pain and degenerative diseases in special occupational groups, like motor vehicle drivers, military vehicle occupants, aircraft pilots, etc. This study aims to establish and validate a neuromuscular human body model focusing on improvement of the detailed description of anatomic structures and neural reflex control, for lumbar injury analysis in vibration loading environments.

METHODS

A whole-body musculoskeletal in Opensim codes was first improved by including a detailed anatomic description of spinal ligaments, non-linear intervertebral disc, and lumbar facet joints, and coupling a proprioceptive feedback closed-loop control strategy with GTOs and muscle spindles modeling in Python codes. Then, the established neuromuscular model was multi-levelly validated from sub-segments to the whole model, from regular movements to dynamic responses to vibration loadings. Finally, the neuromuscular model was combined with a dynamic model of an armored vehicle to analyze occupant lumbar injury risk in vibration loadings due to different road conditions and traveling velocities.

RESULT

Based on a series of biomechanical indexes, including lumbar joint rotation angles, the lumbar intervertebral pressures, the displacement of the lumbar segments, and the lumbar muscle activities, the validation results show that the present neuromuscular model is available and feasible in predicting lumbar biomechanical responses in normal daily movement and vibration loading environments. Furthermore, the combined analysis with the armored vehicle model predicted similar lumbar injury risk to the experimental or epidemiologic studies. The preliminary analysis results also showed that road types and travelling velocities have substantial combined effects on lumbar muscle activities, and indicated that intervertebral joint pressure and muscle activity indexes can need to be jointly considered for lumbar injury risk evaluation.

CONCLUSION

In conclusion, the established neuromuscular model is an effective tool to evaluate vibration loading effects on injury risk of the human body and assist vehicle design vibration comfort by directly concerning the human body injury itself.

A mathematical approach to estimate micro-displacement of a dental implant using electromagnetic Frequency Response Analysis

The aim of this paper is to formulate a mathematical model of dental prosthetic using single degree of freedom (SDOF) to assess the micro-displacement under electromagnetic excitation. Using Finite Element Analysis (FEA) and values from literature, stiffness and damping values of the mathematical model were estimated. For ensuring the successful implantation of dental implant system, monitoring of primary stability in terms of micro-displacement is crucial. One of the most popular techniques for the measurement of stability is the Frequency Response Analysis (FRA). This technique assesses the resonant frequency of vibration corresponding to the maximum micro-displacement (micro-mobility) of the implant. Among the different FRA techniques, the most common method is the Electromagnetic FRA. The subsequent displacement of the implant in the bone is estimated by equations of vibration. A comparison has been made to observe the variation in resonance frequency and micro-displacement due to varying input frequency ranges of 1-40 Hz. The micro-displacement and corresponding resonance frequency were plotted using MATLAB and the variation in resonance frequency is found to be negligible. The present mathematical model is a preliminary approach to understand the variation of micro-displacement with reference to electromagnetic excitation force and to obtain the resonance frequency. The present study validated the use of input frequency ranges (1-30 Hz) with negligible variation in micro-displacement and corresponding resonance frequency. However, input frequency ranges beyond 31-40 Hz is not recommended due to large variation in micromotion and corresponding resonance frequency.

Assessment of vibration modulated regional cerebral blood flow with MRI

Human brain experiences vibration of certain magnitude and frequency during various physical activities such as vehicle transportation and machine operation, which may cause traumatic brain injury or other brain diseases. However, the mechanisms of brain pathogenesis due to vibration are not fully elucidated due to the lack of techniques to study brain functions while applying vibration to the brain at a specific magnitude and frequency. Here, this study reported a custom-built head-worn electromagnetic actuator that applied vibration to the brain in vivo at an accurate frequency inside a magnetic resonance imaging scanner while cerebral blood flow (CBF) was acquired. Using this technique, CBF values from 45 healthy volunteers were quantitatively measured immediately following vibration at 20, 30, 40 Hz, respectively. Results showed increasingly reduced CBF with increasing frequency at multiple regions of the brain, while the size of the regions expanded. Importantly, the vibration-induced CBF reduction regions largely fell inside the brain's default mode network (DMN), with about 58 or 46% overlap at 30 or 40 Hz, respectively. These findings demonstrate that vibration as a mechanical stimulus can change strain conditions, which may induce CBF reduction in the brain with regional differences in a frequency-dependent manner. Furthermore, the overlap between vibration-induced CBF reduction regions and DMN suggested a potential relationship between external mechanical stimuli and cognitive functions.

Reduction of vibration and noise pollution from agricultural tractor engine using novel pine oil and soapnut oil methyl ester as fuel

The exhaust emissions from automotive diesel engines are successfully controlled over the years by adopting different combustion strategies and after treatment devices, whereas the combustion induced vibration and noise are the major pollutant in off-road vehicle engines and yet to be optimized. In the present study, a twin cylinder, Simpson's S-217 tractor diesel engine was used to evaluate the performance, combustion, vibration, and noise characteristics, using biofuel blends. For this study, the blends of pine oil - soapnut oil biodiesel (P75SNB25), diesel - soapnut oil biodiesel (SNB20) and diesel were used as fuel. The pine oil used in this research was purchased and used in its neat form. The soapnut oil was extracted from the soapnut seeds by cold pressing method and trans-esterified in two stages by using methanol and catalysts. The experimental results revealed that the performance and combustion characteristics of the blend P75SNB25 was superior to diesel and the blend SNB20 was slightly inferior to diesel. For the blend P75SNB25, the amplitude of acceleration with respect to time was reduced by 19.48% and 11.58% at no load and full load conditions respectively, whereas for the blend SNB20, the amplitude of acceleration showed a reduction of 14.27% and 9.46% at no load and full load conditions respectively in comparison with diesel operation. But both the blends P75SNB25 and SNB20 showed a maximum reduction of noise by 2.34% at different engine loads compared to diesel operation.

The effects of vibration on the neuronal activity of lateral vestibular nuclei in unilaterally labyrinthectomized rats

Unilateral labyrinthectomy causes distinct oculomotor and postural disorder syndromes that gradually deteriorate. Simultaneously, compensatory mechanisms for the suppression of pathological disorders were activated. The current study aimed to investigate the characteristics of impulse activity in the ipsilateral and contralateral neurons of the lateral vestibular nucleus of unilaterally labyrinthectomized rats during various periods of vibration exposure. A program analysis of the background impulse activity of the neurons in the right- and left-lateral vestibular nuclei of rats under normal condition and after right-sided labyrinthectomy was performed. The animals were subjected to different periods of vibration exposure 2 days after surgery (5-, 10-, and 15-day periods). A comparison of the characteristics of the background impulse activity of neurons in both nuclei of intact rats revealed an initial asymmetry in the values of the mean impulse frequency and coefficient of variation of interimpulse intervals. After 5 days of vibration exposure, the values of the mean impulse frequency of neurons in both Deiters' nuclei were almost equal in labyrinthectomized rats. The mean impulse frequency of neurons on the uninjured side was higher than that on the injured side on the days following vibration exposure. The characteristics and functional significance of the findings are discussed.

[Evaluation of the results and feasibility of vibration, diuresis and inversion therapy in the treatment of upper urinary tract stones]

OBJECTIVES

To evaluate the feasibility, efficiency, and predictive factors of therapeutic success of Vibration, Diuresis and Inversion (VDI) therapy for the removal of upper urinary tract stones.

METHODS

It is a retrospective, single-center study at the CHU - La Conception, Marseille, France including all patients treated with VDI from 2013 to 2018. VDI was indicated for stones <6mm in first-line treatment or for residual fragments <6mm after ureteroscopy, PCNL, microPCNL. The protocol included 4 sessions in outpatient care from 2013 to 2015 then 6 sessions from 2015 to 2018 and a final radiological evaluation.

RESULTS

In total, 109 patients or 489 sessions are reported: median age was 55 years [14-84], median BMI 25kg/m² [15-37], average cumulative size of kidney stones 3mm ±4. VDI was performed after flexible ureteroscopy (62%), SWL (20%), percutaneous treatment (9%) or as a first-line treatment (9%). Compliance was 87 %. The median VAS during the session was 0[0-8]. The incidence of post-session renal colic was 4% (all Clavien I). The postoperative fragment-free and microfragment rates were respectively 39% and 21%, i.e. an overall success of 60% for kidney stones, and 43% and 21%, i.e. an overall success of 64% for lower pole kidney stones.

CONCLUSION

VDI is a simple, non invasive and well tolerated technique for the elimination of small renal lithiasis after SWL, ureteroscopy, PCNL or as a first-line treatment.

Vibration motor stimulation device in smart leggings that promotes motor performance in older people

Globally, accelerated aging is taking place alongside increased life expectancy of the population. This poses a challenge to maintaining autonomy and independence as people age but preventing falls and disabilities. Currently, there are few specific technologies on the market that are focused on the rehabilitation and promotion of autonomy in older adults. This study presents the development of a prototype (Myoviber®) of a low-cost, wearable everyday garment, designed to stimulate the lower limbs by the application of focal muscle vibration and incorporating technical textile qualities. The presented approach is proactive and preventive, maintaining functionality for the elderly while integrating electronic technology into an everyday garment. For this, a comprehensive study was carried out that included the design of the leggings through anthropometric analyses, the development of vibration devices at a stable frequency located in the knee extensor muscle and a smart belt with wireless connection, and the optimization of the battery autonomy. The development of the prototype was carried out through the construction of a vibratory device, which was validated with biomechanical evaluations. The results show an increase in the functional capacity of the lower limbs, in relation to motor tasks such as postural balance and gait in older people.

Change of Phonation in Canines Without Vocal Fold Paralysis After Vocal Processes Resection

The effects of the vocal processes resection on phonation in an animal without vocal fold paralysis have not been clarified. The present study used an in vivo animal model with vocal processes resection and excised larynges phonation model to investigate the effects of the vocal processes resection on phonation. Six months after resection of bilateral vocal fold processes, glottal airflow, subglottal air pressure, acoustic signals, and ultra-high-speed video images were recorded in the excised larynges phonation model of canine. Glottal aerodynamic parameters were estimated by calculation of subglottal pressure and glottal flow. Histological analyses of the scarred were assessed for wound healing completion. In the vocal processes resection group, fundamental frequency(F0) and vocal intensity decreased, and the Jitter and Shimmer increased significantly. The phonation threshold power(PTW) of the vocal processes resection was significantly higher than controls. The vibratory amplitude of the vocal fold posterior and visual vocal fold vibration length increased. Expression of collagen I-III in scarred tissue samples in vocal process resection was similar to controlling soft tissue specimens around vocal process cartilage, and collagen fiber formed matured thick bundles. The results suggest that the F0, voice quality, and vocal intensity significantly decreased after complete wound healing of vocal processes resection in canines without vocal folds paralysis. The higher PTW and posterior scarred vocal vibration may be the dynamic reasons.

The effects of whole-body vibration and head supported mass on performance and muscular demand

For military rotary-wing aircrew, little is known about the interactive effects of vibration exposure and the addition of head supported mass (HSM) on target acquisition performance, head kinematics, and muscular demand. Sixteen healthy male participants wore an aviator helmet with replica night vision goggles and completed rapid aiming head movements to acquire visual targets in axial and off-axis movement trajectories while secured in a Bell-412 helicopter seat mounted to a human-rated shaker platform. HSM configuration (with or without a counterweight (CW)) and vertical whole-body vibration (WBV) conditions (vibration or no vibration exposure) were manipulated as independent variables. WBV exposure degraded target acquisition performance and lengthened time to peak velocity of head movements. For yaw peak velocity in the axial movement trajectory, peak velocity was 9.9%, 11.6%, and 8.4% higher in the noCW + WBV condition compared to the CW + WBV, CW + noWBV, and noCW + noWBV conditions, respectively.Practitioner summary: The majority of military helicopter aircrew use a counterweight to counteract the anteriorly displaced load of night vision googles. This study was undertaken to better understand how helicopter vibration and counterweight use interactively affect performance and health-related measures during rapid scanning head movements.

Shoulder vibratory exercises improves shoulder external rotation muscle strength and shoulder function: Randomized comparison trial

BACKGROUND

Based on electromyography measurements, shoulder vibratory exercises efficiently stimulate shoulder muscles activity. Yet very few studies have supported that shoulder vibratory exercises increased shoulder muscles strength and function, and the noninferiority compared with conventional elastic resistance exercises remains unknown.

OBJECTIVE

This study investigated the effect of vibratory exercises versus conventional elastic resistance exercises with elastic bands on shoulder external rotation muscles strength and functional performance in young adults.

METHODS

26 young adults (7 males and 19 females, with age 23.89 ± 3.02) were recruited and randomly allocated to shoulder vibratory exercises with FLEXI-BAR (FLEXI-BAR group) or conventional resistance exercises with elastic band (TheraBand group) for 3 times/week, 4 weeks totally. Shoulder external rotator muscles strength test and Underkofler softball distance throw test (USDTT) were performed before and after the training period.

RESULTS

After 4 weeks training, shoulder external rotator muscles strength increased 22.25 ± 15.06 N (P= 0.004, effect size = 1.48) within FLEXI-BAR group and 22.81 ± 14.94 N (P= 0.007, effect size = 1.53) within TheraBand group. There were no statistically significant differences between groups in the three muscle strength tests (P> 0.65). Regarding shoulder function, FLEXI-BAR exercises increased the throw distance 0.81 ± 0.92 meters in USDTT (P= 0.041, effect size = 0.88) while TheraBand exercise did not (P= 0.284), yet there was no statistically significant between group effects (P= 0.608).

CONCLUSIONS

These findings suggest that shoulder vibratory exercises can improve shoulder muscles strength in young adults and can be a useful alternative to the conventional elastic resistance exercises to improve the shoulder muscles strength and function. This provides therapists with more options in terms of choosing training equipment for rehabilitation programs.

Association between physical risk factors and sleep disturbance among workers in Korea: The 5th Korean Working Conditions Survey

OBJECTIVE

Sleep disturbance is associated with negative effects to workers' health and productivity; hence, it is important to find which population of workers are associated with sleep disturbance. This study aimed to investigate the association between physical risk factors (vibration, noise, high, and low temperatures) and sleep disturbance in the Korean working population.

METHODS

We analyzed data on 29,213 paid workers from the 5th Korean Working Conditions Survey. Individual and occupational characteristics, physical risk factors exposure, and sleep disturbance were collected using self-reported questionnaires. To assess the association between physical risk factors and sleep disturbance, the chi-square test and multivariable logistic regression models were conducted. All statistical analyses were performed in sex-based subgroups.

RESULTS

We observed that all physical risk factors are associated with sleep disturbance. The adjusted odds ratios (95% confidence interval [CI]) of severe exposure to vibration, noise, high and low temperature were 1.69 (CI:1.47-1.94), 2.52 (CI:2.17-2.92), 3.09 (CI:2.69-3.56), and 1.96 (CI:1.68-2.28) in male workers and 2.27 (CI:1.89-2.72), 3.52 (CI:2.92-4.24), 3.30 (CI:2.81-3.87), and 2.87 (CI:2.44-3.38) in female workers, respectively. The prevalence of sleep disturbance increased with increased exposure to physical risk factors, indicating a dose-response relationship.

CONCLUSIONS

Physical risk factors exposure in the workplace was associated with sleep disturbance of workers, indicating a dose-response relationship. Given the impact of sleep disturbance on workers' health and efficiency, it may be important to control exposure to physical risk factors in the working environment with regards to sleep conditions.

Vibratory and plantar pressure stimulation: Steps to improve freezing of gait in Parkinson's disease

INTRODUCTION

Freezing of gait (FOG) is a devastating symptom that develops in patients with advanced Parkinson's disease (PD) and is often unresponsive to pharmacological treatment. Recent research suggests that FOG may result from dysfunctional plantar peripheral sensory systems. The impact of combined plantar pressure and vibratory stimulation over vibratory or pressure alone on FOG remains unexplored.

METHODS

PD patients with FOG were randomised into four groups and treated with combined vibratory and pressure stimulation, vibratory stimulation alone, pressure stimulation alone, or controls (no stimulation). Vibratory stimulation targeted both Achilles' tendons. Simultaneous bilateral pressure stimulation was applied to the first hallux, first metatarsal bone, and the sole. The primary outcome included normalized percent changes in percent FOG measured both pre- and immediately post-stimulation. Other outcomes including clinical rating scale, response to questionnaires, number and duration of freezing episodes, and spatiotemporal gait parameters at pre- and freezing episodes were also explored.

RESULTS

Sixty PD patients participated in the study. Patients who were treated with combined vibratory and pressure stimulation responded with significant decreases in normalized percent changes of percent FOG (62.75 ± 25.54%, p < 0.001) compared with those treated with vibration alone (11.38 ± 8.29%, p < 0.001), pressure alone (15.15 ± 16.18%, p < 0.001), or controls (8.59 ± 16.85%, p < 0.001).

CONCLUSION

Our study demonstrated the benefit of combined vibratory and pressure stimulation on FOG suggesting that this strategy might be developed as a novel treatment modality for PD patients with FOG.

Vibration Measurements of the Gerbil Eardrum Under Quasi-static Pressure Sweeps

Tympanometry provides an objective measurement of the status of the middle ear. During tympanometry, the ear-canal pressure is varied, while the response of the ear to sound pressure is measured. The effects of the pressure on the mechanics of the middle ear are not well understood. This study is a continuation of our previous work in which the vibration response of the gerbil eardrum was measured in vivo under quasi-static pressure steps. In this study, we delivered a continuous pressure sweep to the middle ear and measured the vibration response at four locations for six gerbils. Vibrations were recorded using a single-point laser Doppler vibrometer and glass-coated reflective beads (diameter ~ 40 µm) at the umbo and on the mid-manubrium, posterior pars tensa and anterior pars tensa.The vibration magnitudes were similar to those in the previous step-wise pressurization experiments. Most gerbils showed repeatability within less than 10 dB for consecutive cycles. As described in the previous study, as the frequency was increased at ambient pressure, the vibration magnitude on the manubrium increased slightly to a broad peak (referred to as R1) and then decreased until a small peak appeared (referred to as R2), followed by multiple peaks and troughs as the magnitude decreased further. The low-frequency vibration magnitude (at 1 kHz) decreased monotonically as the pressure became more negative except for a dip (about 500 Pa wide) that occurred between - 700 and - 1800 Pa. The lowest overall magnitude was recorded in the dip at mid-manubrium. The vibration magnitudes also decreased as the middle-ear pressure was made more positive and were larger than those at negative pressures. R1 was only visible at negative and small positive middle-ear pressures, while R2 was visible for both positive and negative pressures. R2 split into multiple branches after the middle-ear pressure became slightly positive. No magnitude dip was visible for positive middle-ear pressures.The low-frequency vibration magnitudes at negative middle-ear pressures on the pars tensa were higher than those on the manubrium. R1 was not visible for large negative middle-ear pressures on the pars tensa. R2 appeared as a multi-peak feature on the pars tensa as well, and a higher-frequency branch on the posterior pars tensa appeared as a trough on the anterior pars tensa. The magnitude dip was not present on the pars tensa. The largest overall magnitude was recorded at the R2 peak on the posterior pars tensa.The results of this study expand on the findings of the step-wise pressurization experiments and provide further insight into the evolution of the vibration response of the eardrum under quasi-static pressures.

Focal vibration of the plantarflexor and dorsiflexor muscles improves poststroke spasticity: a randomized single-blind controlled trial

BACKGROUND

Post-stroke spasticity is a cause of gait dysfunction and disability. Focal vibration (FV) of agonist-antagonist upper limb muscle pairs reduces flexor spasticity; however, its effects on ankle plantarflexor spasticity are uncertain.

OBJECTIVE

To assess the effects of focal vibration administered by a trained operator to the ankle plantarflexor and dorsiflexor muscles on post-stroke lower limb spasticity.

METHODS

A randomized, single-blind controlled trial of 64 participants with stroke and plantarflexor spasticity assigned to 3 groups by centralized, computer-generated randomization (1:1:1): 1) physiotherapy alone (CON), 2) physiotherapy+gastrocnemius vibration (FV_GM) and 3) physiotherapy+tibialis anterior vibration (FV_TA). Physiotherapists and assessors were blinded to group assignment. The experimental groups underwent 15, 20-min vibration sessions at 40 Hz. We performed evaluations at baseline and after the final treatment: Modified Ashworth Scale (MAS), Clonus scale, Functional Ambulation Categories (FAC), Fugl-Meyer Assessment - Lower Extremity (FMA_LE), Modified Barthel Index (MBI), and electromyography and ultrasound elastography. Primary outcome was remission rate (number and proportion of participants) of the MAS.

RESULTS

MAS remission rate was higher in FV_GM and FV_TA than CON groups (CON vs. FV_GM: p=0.009, odds ratio 0.15 [95% confidence interval 0.03-0.67]; CON vs. FV_TA: p=0.002, 0.12 [0.03-0.51]). Remission rate was higher in the experimental than CON groups for the Clonus scale (CON vs. FV_GM: p<0.001, OR 0.07 [95% CI 0.01-0.31]; CON vs. FV_TA: p=0.006, 0.14 [95% CI 0.03-0.61]). FAC remission rate was higher in the FV_TA than the CON (p=0.009, 0.18 [0.05-0.68]) and FV_GM (p=0.014, 0.27 [0.07-0.99]) groups. Ultrasound variables of the paretic medial gastrocnemius decreased more in FV_GM than CON and FV_TA groups (shear modulus: p=0.006; shear wave velocity: p=0.008).

CONCLUSIONS

Focal vibration reduced post-stroke spasticity of the plantarflexor muscles. Vibration of the tibialis anterior improved ambulation more than vibration of the gastrocnemius or physiotherapy alone. Gastrocnemius vibration may reduce spasticity by changing muscle stiffness.

Superimposed vibration on suspended push-ups

Background

Superimposition of vibration has been proposed in sports training using several devices and methods to enhance muscle activation and strength adaptations. Due to the popularity of suspension training, vibration systems have recently been developed to increase the effects of this training method. The present cross-sectional study aims to examine the effects of superimposing vibration on one of the most popular exercises in strength and conditioning programs: push-ups.

Methods

Twenty-eight physically active men and women executed push-ups in three suspended conditions (non-vibration, vibration at 25 Hz, and vibration at 40 Hz). OMNI-Res scale was registered, and surface electromyographic signals were measured for the activity of the right and left external oblique, anterior deltoid, triceps brachii, sternal, and clavicular heads of the pectoralis major.

Results

A linear mixed model indicated a significant fixed effect for vibration at 25 Hz and 40 Hz on muscle activity. Suspended push-ups with superimposed vibration (25 Hz and 40 Hz) showed a significant higher activity on left (25 Hz: p = 0.036, d = 0.34; 40 Hz: p = 0.003, d = 0.48) and right external oblique (25 Hz: p = 0.004, d = 0.36; 40 Hz: p = 0.000, d = 0.59), anterior deltoid (25 Hz: p = 0.032, d = 0.44; 40 Hz: p = 0.003, d = 0.64), and global activity (25 Hz: p = 0.000, d = 0.55; 40 Hz: p = 0.000, d = 0.83) compared to non-vibration condition. Moreover, OMNI-Res significant differences were found at 25 Hz (6.04 ± 0.32, p = 0.000 d = 4.03 CI = 3.27, 4.79) and 40 Hz (6.21 ± 0.36 p = 0.00 d = 4.29 CI = 3.49, 5.08) compared to the non-vibration condition (4.75 ± 0.32).

Conclusion

Superimposing vibration is a feasible strategy to enhance the muscle activity of suspended push-ups.

Effects of whole body vibration exercise combined with weighted vest in older adults: a randomized controlled trial

BACKGROUND

To evaluate the training effects of whole body vibration (WBV) combined with weighted vest (WV) in older adults.

METHODS

This randomized controlled trial study was conducted in healthy older adults living in the community. Fifty-one participants were randomly allocated into 3 groups: group 1 (n = 17), WBV alone, training on WBV at a frequency 30 Hz, amplitude 2 mm, 10 sets of 1 min squats, with 60 s rest, group 2 (n = 15), WV alone, squat exercise, 10 sets of 1 min, with 60 s rest, while WV loaded with 10% body weight and group 3 (n = 19), WBV + WV, combining WBV exercise with the addition of a WV. All groups completed training 3 times per week for 8 weeks. The outcomes were total muscle mass, muscle thickness, maximal isometric strength, single-leg-stance and timed-up-and-go evaluated at baseline and after training.

RESULTS

As a result of training all groups improved their isometric muscle strength with little difference between groups. The single-leg-stance significantly improved only in WBV + WV group 25.1 ± 10.8 s (mean ± 95% CI, p < 0.01). The timed-up-and-go improved in all groups, but the improvement was significantly greater in the WBV + WV group (17.5 ± 6.9%) compared to the WV (8.5 ± 3.2%) and WBV groups (9.2 ± 5.4%, p = 0.043, 0.023 respectively). Rectus femoris muscle thickness and total muscle mass were significantly increased in all groups equally with little difference between groups.

CONCLUSION

The combined WBV + WV had a greater effect on the single-leg-stance and the timed-up-and-go compared to WV or WBV alone.

TRIAL REGISTRATION

TCTR20190306001. Thai Clinical Trials Registry ( www.thaiclinicaltrials.org ). Date of registration: 6 March 2019.

The bone-muscle connection in breast cancer: implications and therapeutic strategies to preserve musculoskeletal health

Breast cancer and its therapies frequently result in significant musculoskeletal morbidity. Skeletal complications include bone metastases, pain, bone loss, osteoporosis, and fracture. In addition, muscle loss or weakness occurring in both the metastatic and curative setting is becoming increasingly recognized as systemic complications of disease and treatment, impacting quality of life, responsiveness to therapy, and survival. While the anatomical relationship between bone and muscle is well established, emerging research has led to new insights into the biochemical and molecular crosstalk between the skeletal and muscular systems. Here, we review the importance of both skeletal and muscular health in breast cancer, the significance of crosstalk between bone and muscle, and the influence of mechanical signals on this relationship. Therapeutic exploitation of signaling between bone and muscle has great potential to prevent the full spectrum of musculoskeletal complications across the continuum of breast cancer.

Label-free detection of leukemic myeloblasts in hyaluronic acid

Chronic myeloid leukemia is generally required bone marrow biopsy for diagnosis. Although examining peripheral blood is less invasive, it has not been fully validated as a routine diagnostic test due to suboptimal sensitivity. To overcome this limitation, a number of methodologies based on microfluidics have been developed for sorting circulating tumor cells from peripheral blood of patients with leukemia.

In order to develop a more convenient method, we designed an analysis protocol using motion microscopy that amplifies cellular micro motions in a captured video by re-rendering pixels to generate extreme magnified visuals. Intriguingly, no fluctuations around leukemic myeloblasts were observed with a motion microscope at any wavelength of 0–10 Hz. However, use of 0.05% hyaluronic acid, one type of non-newtonian fluid, demonstrated fluctuations around leukemic myeloblasts under conditions of 25 μm/s and 0.5–1.5 Hz with a motion microscope.

Thus, the non-invasive detection of leukemic myeloblasts can offer a valuable supplementary diagnostic tool for assessment of drug efficacy for monitoring patients with chronic myeloid leukemia.

Effect of Whole-Body Vibration Exercise on Hamstrings-to-Quadriceps Ratio, Walking Performance, and Postural Control in Children With Hemiparetic Cerebral Palsy: A Randomized Controlled Trial

OBJECTIVE

The purpose of this study was to investigate the effect of whole-body vibration (WBV) exercises combined with traditional physiotherapy on the hamstrings-to-quadriceps (H:Q) ratio, walking ability, and control of posture in children with hemiparetic cerebral palsy (CP).

METHODS

A total of 34 children with spastic hemiparetic CP (boys and girls) participated in this 2-arm, parallel, randomized controlled trial. The inclusion criteria were spasticity ranging from 1 to 1+, gross level skills (I and II), at least 1 meter tall, standing alone, and walking forward and backward. They were randomly allocated to the control group (traditional physiotherapy) and study group and were treated by the same physiotherapy program combined with WBV training (3 times per week for 2 successive months). Quadriceps and hamstring muscle strength, walking performance, and postural control were evaluated before and after intervention by a blinded assessor.

RESULTS

The post-intervention values of the hamstring and quadriceps muscle force, gross motor function, and stability indices of the 2 groups were higher than the pre-values (P < .05). In addition, the post-values of the study group were higher than those of the control group (P < .05). Regarding the H:Q ratio, there was no significant difference between pre-values or the post-values of both groups (P = .948 and P = .397, respectively). There were no significant differences between the pre- and post-values of each group (P = .500 and P = .195, respectively).

CONCLUSION

Eight weeks of WBV training combined with traditional physiotherapy was more effective than traditional physiotherapy alone in improving walking ability and postural control. Furthermore, the combined intervention strengthened the quadriceps and hamstring muscles, with no change in the H:Q ratio in children with hemiparetic CP.

Quasi-static cyclic behavior of wire rope isolators: comprehensive experimental study and improved mathematical modeling

Wire rope isolators (WRI) effectively isolate shocks and vibrations, making them an ideal choice for many industries, including military and aerospace. A sizeable experimental program was conducted to investigate the cyclic hysteretic behavior of WRIs in all possible loading directions. The test matrix included several isolators subjected to different load-displacement amplitudes at varying rates and other geometries and sizes of the WRIs themselves. This study evaluates the effective stiffness and damping characteristics of WRIs in both the tension/compression (or vertical) and shear/roll (or lateral) directions through laboratory tests and mathematical modeling. It was found that the wire rope diameter significantly influences the stiffness of the WRI more than the other geometric characteristics. Additionally, the damping characteristics of the WRI were found to be correlated to the height-to-width ratio for a given wire rope diameter. The cyclic loading tests showed that, unlike in the lateral directions, in the vertical direction, the load-displacement hysteresis loops are asymmetric. Therefore, the original Bouc-Wen model of hysteresis was used for the lateral direction. A modified version of the same model was developed to simulate the observed asymmetric hysteretic behavior in the vertical direction.

Effect of Mechanical Micro-Vibrations on The Efficiency of Leopard Inter-Species Somatic Cell Nuclear Transfer

OBJECTIVE

Scarcity of oocytes for assisted reproduction in endangered species can be bypassed by interspecies somatic cell nuclear transfer (iSCNT). In Felids, domestic cat (Felis catus) oocytes can serve as recipients for the nucleus of the endangered Persian leopard (Panthera pardus saxicolor). However, in vitro oocyte maturation is still suboptimal in cats, whereas it has been reported to benefit from micro-vibration in non-felid species. Therefore, the present study is aimed to determine whether micro-vibration, applied during in vitro maturation (IVM), improves the embryogenic potential of cat oocytes transplanted with fibroblast nuclei of the Persian leopard.

MATERIALS AND METHODS

In the experimental study, cat cumulus-oocyte complexes (COCs) were randomly assigned to the treatment group (micro-vibration) or control group (static culture). Resultant metaphase II (MII) oocytes were enucleated and reconstructed with nucleus transplants from leopard fibroblasts, followed by artificial oocyte activation and embryo culture under the same condition (static) for 7 days.

RESULTS

While cumulus cell expansion and oocyte maturation profited from micro-vibration (P<0.05), the quantity and quality of blastocysts were significantly lower in micro-vibration than in the control group (P<0.05). The total number of blastocyst cells tended to be lower in the micro-vibration than in the control group (P=0.075). Nevertheless, the proportion of ICM and TE cells did not differ between the micro-vibration and control groups (P>0.05).

CONCLUSION

The present study indicated that micro-vibration at a frequency of 44 Hz for 5 secs per hour enhanced nuclear maturation and cumulus cell expansion of cat oocytes. However, exposure to micro-vibration during IVM impaired the survival rate of reconstructed oocytes during the iSCNT process and their developmental competence toward the blastocyst stage.

3E enhancement of freshwater productivity of solar still with heater, vibration, and cover cooling

This study focused on experimentally increasing the productivity of freshwater from solar stills. The performance of a single solar still system could be augmented with the combination of an electric heater, vibration motion, and thermoelectric cooling. The study investigated the effects of combining two of these components and finally combining all of them on freshwater productivity. The electric heater and vibration motion are used to enrich the evaporation rate, while thermoelectric coolers are used to enhance the condensation rate, leading to high freshwater productivity. The proposal, construction, and testing of two identical solar stills were performed under the local climate conditions of the city of Alexandria in northwestern Egypt during the summer and winter times. The two solar stills had a 1-m² base area. An electric heater of 450 W was placed inside the modified solar still. The modified solar still was fixed on four coiled springs. A 1-hp power DC motor, an inverter, a control unit, and two 330-W photovoltaic solar panels were attached to the modified solar still. Eccentric masses were mounted on the rotating disk attached to the DC motor to generate the vibration. Under the same climate conditions, the daily output of freshwater was measured experimentally for the modified case and the conventional solar. The daily rates of freshwater productivity in summer were investigated for four cases and the conventional one. Results showed that the peak daily freshwater productivity achieved with the solar heater, thermoelectric coolers, and vibration motion was 12.82 kg/day, with a maximum estimated cost of 0.01786 $/L/m².The exergoeconomic of the modified solar still with heater, vibration, and thermoelectric cooler was greater than that of conventional ones. The highest CO₂ mitigation of the case (5) and that of the conventional solar desalination were about 160 tons and 28 tons, respectively.

Mechanical-based therapies may reduce pain and disability in some patients with knee osteoarthritis: A systematic review with meta-analysis

BACKGROUND

Mechanical-based therapies are not yet recommended to manage osteoarthritis (OA). This systematic review and meta-analysis aim to assess the effects of passive mechanical-based therapies (isolated or combined with other therapies) on patients with knee OA compared to placebo, other isolated or combined interventions.

METHODS

Pubmed, Cochrane, Web of Science and EMBASE were searched up to December 2020. We included randomized and non-randomized trials using therapeutic ultrasound, phonophoresis, extracorporeal shockwave therapy (ESWT) and vibration (single or combined with other therapies) compared to placebo, and/or other physical therapies groups. Biochemical, patient-reported, physical and imaging outcome measures were retrieved. We judged risk of bias using the RoB2 tool for randomized studies, the ROBINS-I tool for non-randomized studies, and the GRADE to interpret certainty of results.

RESULTS

We included 77 clinical studies. Ultrasound and ESWT statistically improved pain and disability comparing to placebo (combined or not with other therapies), and when added to other therapies versus other therapies alone. Ultrasound was statistically inferior to phonophoresis (combined or not with other therapies) in reducing pain and disability for specific therapeutic gels and/or combined therapies. Vibration plus exercise statistically improved pain relief and function versus exercise alone. All meta-analyses showed very-low certainty of evidence, with 15 of 42 (38%) pooled comparisons being statistically significant (weak to large effect).

CONCLUSIONS

Despite the inconsistent evidence with very-low certainty, the potential benefits of passive mechanical-based therapies should not be disregard and cautiously recommended that clinicians might use them in some patients with knee OA.