Increased skin temperature after vibratory stimulation

The Effect of Vibration Massage on Fatigue of the Upper Trapezius Muscle during Different Tasks

Background: Vibratory massage is now widely used to alleviate muscle fatigue. The effects of different vibration massage intensities on left and right upper trapezius (UT) fatigue have not been examined. Therefore, the present study first examined whether a vibration massage intervention had an effect on UT muscles and second compared the effects of 2 different levels (36 Hz and 46 Hz) of vibratory massage on the right and left oblique muscles under 3 different fatigue conditions. Methods: A total of 23 participants (12 female, 11 male; age: 26.5 ± 3.9 year, height: 170.5 ± 1.6 cm, mass: 57.5 ± 1.5 kg, BMI: 24.3 ± 1.6 kg/m2) were randomly divided into intervention and control groups. The 2 groups of subjects completed isometric contraction fatigue tasks of 30 s of fatigue, 60 s of fatigue and 90 s of fatigue in turn. The specific task of isotonic contraction was performed by subjects holding a 1 kg dumbbell in each hand and performing a straight arm weighted lateral supination exercise. After each exercise, the intervention group was randomized to apply a massage device with a vibration intensity of 36 Hz or 46 Hz on the left and right UT muscles for 5 min each. The control group did not receive any treatment. Both groups then repeated the same fatigue task as before. Then, the effects of different vibration massage interventions on UT muscles were derived by analyzing the changes in maximal voluntary contraction percentage (MVC%) of surface electromyography (sEMG) signals before and after the intervention, and the most effective vibration massage program for relieving left and right UT fatigue was summarized. Then, four classification algorithms were used to label and classify the collected sEMG data, and finally a UT muscle fatigue identification and vibration massage model was constructed. Results: After using the vibration massage level 1 (36 Hz) intervention, the MVC% of the right UT muscle showed significant reductions in the 30 s fatigue task, the 60 s fatigue task and the 90 s fatigue task (R1: p = 0.022, R2: p = 0.005, R3: p = 0.049). After using the vibration massage level 3 (46 Hz) intervention, the MVC% of the right UT muscle showed a significant decrease in both the 60 s fatigue task and the 90 s fatigue task (R2: p = 0.033, R3: p = 0.028). Significant decreases in MVC% for the left UT muscle were found only in the 90 s fatigue task (L3: p = 0.040). Then, by comparing the different performances of four commonly used classification algorithms, it was found that the bagging (accuracy = 0.860) algorithm had higher accuracy. Therefore, the bagging algorithm was used for the UT fatigue identification and vibration massage models. Conclusions: This was the first study to show the impacts of different levels of vibration massage on fatigue alleviation in the left and right UT muscles. Furthermore, the bilateral UT fatigue identification and vibration massage model developed in this study can help people to choose the most appropriate massage protocol for quick relief and relaxation of the UT muscles under three different fatigue tasks.

Effect of Vibration Massage and Passive Rest on Recovery of Muscle Strength after Short-Term Exercise

Background: The aim of the study was to compare the effect of vibration massage and passive rest on accelerating the process of muscle recovery after short-term intense exercise. Methods: Eighty-four healthy men aged 20 to 25 years participated in the study. Study participants performed isometric (ISO-M Group) and auxotonic (AUX-M group) contraction exercise in the lower limbs. Vibration massage was administered after exercise in the first recovery period. In the same period, controls rested passively, without the support of vibration massage. To assess the effectiveness of the applied vibration, a 4-fold measurement of the maximum force of the muscles involved in the exercise was performed under conditions of isometric contractions on a leg press machine set at an angle of 45° degrees upwards. Results: Differences in maximum strength during isometric contraction were found compared to baseline in favor of the groups subjected to the experimental vibration massage. Differences were demonstrated in muscle strength between the study groups (p < 0.005). The second period of passive rest in all groups did not bring significant changes in the values of maximal lower limb strength. Conclusions: Properly selected characteristics of the vibration effect can be an effective method in accelerating recovery and regaining lost motor capabilities of muscle groups fatigued by exercise. This offers the potential to shorten rest periods between sets of repetitions in training or between training units.

Effects of whole body vibration with exercise therapy versus exercise therapy alone on flexibility, vertical jump height, agility and pain in athletes with patellofemoral pain: a randomized clinical trial

Background

Patellofemoral pain (PFP) is the most prevalent orthopedic problem in active young adults. Due to its multifactorial etiology, a variety of therapeutic measures have been adopted to treat PFP, including exercise therapy, electrotherapy, and manual therapy. It has also been suggested that whole body vibration (WBV) can improve neuromuscular function in persons with knee problems. The aim of the present study was to evaluate the effects of adding WBV to routine exercise programs on flexibility, vertical jump height, agility and pain in athletes with PFP.

Methods

Twenty-four male athletes with PFP were randomized into two groups of WBV + exercise (n = 12) or exercise only (n = 12). Participants received their interventions during 4 consecutive weeks (12 sessions). Pain intensity, flexibility and agility were assessed respectively as score on a numerical rating scale, the sit-and-reach test, and a modified T-test, and vertical jump height was measured to the nearest centimeter. The tests were done before and after the interventions, and the results were compared between the two groups. Independent t-tests and paired t-tests were used for between- and within-group comparisons, respectively.

Results

After the interventions, all variables for vertical jump height, flexibility, agility and pain intensity improved significantly in both groups (p < 0.05). The flexibility test showed significantly greater improvement in the WBV + exercise group (p<0.001), whereas for vertical jump height, agility and pain intensity, there were no statistically significant differences between groups (p>0.05).

Conclusions

The present findings showed that exercise therapy with and without WBV can significantly decrease pain and increase agility, vertical jump height and flexibility in athletes with PFP. Adding WBV to routine exercise therapy, however, can augment the effects of the latter on flexibility.

Trial registration

IRCT, IRCT20090831002391N39. Registered 7 February 2018, https://en.irct.ir/search/result?query=IRCT20090831002391N39.

Both ipsilateral and contralateral localized vibratory stimulations modulated pain-related sensory thresholds on the foot in mice and humans

Purpose

This study was aimed to investigate the effect of localized vibration on sensory thresholds in mice and humans using a novel quantitative method.

Participants and methods

The sensory thresholds of 7-week-old male C57BL/6J mice were measured with four sine-wave electrostimulation frequencies (5, 50, 250, and 2,000 Hz) before and after applying 2-minute vibration to the plantar side of the foot in mice. In human participants (16 males and 16 females; mean age, 21.0±0.8 years), the sensory threshold was measured at 50 Hz before and after applying 2-minute and 5-minute vibrations to the dorsal side of the foot.

Results

Application of a 2-minute vibration at either the ipsilateral or contralateral side modulated the sensory thresholds elicited by a 5- or 50-Hz right electrostimulation in mice. In human participants, application of a 5-minute vibration at either the ipsilateral or contralateral side modulated the sensory threshold elicited by 50-Hz right electrostimulation, but had no effect on local skin temperature. These results suggest that the right side of pain-related Aδ fibers (50 Hz) or C fibers (5 Hz) was modulated by the localized ipsilateral or contralateral side of vibratory stimuli, respectively, in mice and humans.

Conclusion

The ability of contralateral vibration to modify the right sensory thresholds suggests possible involvement of the central nervous system in vibratory modulation.

Effects of whole body vibration therapy in pain, function and depression of the patients with fibromyalgia

AIM

Aim of the study is to search the effects of whole body vibration (WBV) in fibromyalgia patients.

MATERIALS AND METHODS

In this single blind study 20 fibromyalgia patients were diagnosed according to 2010 American College of Rheumatology criteria whom participated in the study with the mean age of 57 ± 7 (years). Participants were randomized into 2 equal groups. In the intervention group (n = 10), 6 different types of exercises were combined with 30 hz frequency, 2 mm amplitude WBV for 4 weeks, The control group (n = 10) performed the same exercises on the same platform without vibration. The patients were assessed at baseline, at the 3rd and 6th months by Visual Analogue Scale (VAS), Fibromyalgia Impact Questionnaire (FIQ) and Beck Depression Inventory (BDI).

RESULTS

Only FIQ score was significantly better in the treatment group at the 6th month evaluation (p = 0.043).

CONCLUSION

WBV is found to be effective in reducing symptoms of fibromyalgia.

Acute Effect of Whole-Body Vibration Warm-up on Footspeed Quickness

Donahue, RB, Vingren, JL, Duplanty, AA, Levitt, DE, Luk, H-Y, and Kraemer, WJ. Acute effect of whole-body vibration warm-up on footspeed quickness. J Strength Cond Res 30(8): 2286-2291, 2016-The warm-up routine preceding a training or athletic event can affect the performance during that event. Whole-body vibration (WBV) can increase muscle performance, and thus the inclusion of WBV to the warm-up routine might provide additional performance improvements. The purpose of this investigation was to examine the acute effect of a WBV warm-up, using a vertical oscillating platform and a more traditional warm-up protocol on feet quickness in physically active men. Twenty healthy and physically active men (18-25 years, 22 ± 3 years, 176.8 ± 6.4 cm, 84.4 ± 11.5 kg, 10.8 ± 1.4% body fat) volunteered for this study. A 2 × 2 factorial design was used to examine the effect of 4 warm-up scenarios (no warm-up, traditional warm-up only, WBV warm-up only, and combined traditional and WBV warm-up) on subsequent 3-second Quick feet count test (QFT) performance. The traditional warm-up consisted of static and dynamic exercises and stretches. The WBV warm-up consisted of 60 seconds of vertical sinusoidal vibration at a frequency of 35 Hz and amplitude of 4 mm on a vibration platform. The WBV protocol significantly (p ≤ 0.0005, η = 0.581) augmented QFT performance (WBV: 37.1 ± 3.4 touches; no-WBV: 35.7 ± 3.4 touches). The results demonstrate that WBV can enhance the performance score on the QFT. The findings of this study suggest that WBV warm-up should be included in warm-up routines preceding training and athletic events which include very fast foot movements.

Localised application of vibration improves passive knee extension in women with apparent reduced hamstring extensibility: a randomised trial

QUESTION

Does the localised application of vibration over the hamstrings improve hamstring extensibility?

DESIGN

Randomised controlled trial with concealed allocation, intention-to-treat analysis, and assessor blinding.

PARTICIPANTS

30 non-athletic females (aged 18-22 yrs) with limited hamstring extensibility bilaterally.

INTERVENTION

The experimental group received 3 sessions of localised application of vibration per week for 8 weeks. At each session, 3 sets of vibration were applied over the left and right hamstring muscles. The control group continued their usual daily activities. Both groups were asked to perform no specific exercises during the 8-week intervention period.

OUTCOME MEASURES

Hamstring muscle extensibility was measured bilaterally at baseline and at the end of the 8-week intervention period by measuring passive knee extension in supine with 90 deg of hip flexion.

RESULTS

At baseline, the mean lack of knee extension was 27 deg (SD 9) in the experimental group and 24 deg (SD 8) in the control group. At 8 weeks, this had changed to 13 deg (SD 5) in the experimental group and 23 deg (SD 9) in the control group. This was a significant treatment effect: mean between-group difference of 13 deg (95% CI 11 to 16).

CONCLUSION

An 8-week regimen of localised application of vibration over the hamstring muscles significantly reduces knee extension lack in women with reduced range on the passive knee extension test.

Comparing muscle temperature during static and dynamic squatting with and without whole-body vibration

The aim of this study was to investigate the influence of shallow dynamic squatting (DS) versus static squatting (SS) with or without concurrent side-to-side alternating whole-body vibration (WBV) on vastus lateralis temperature and cardiovascular stress as indicated by heart rate (HR). Ten participants (five men, five women) participated in four interventions [DS with WBV (DS+), DS without WBV (DS-), SS with WBV (SS+), SS without WBV (SS-)] 48 h apart, in a randomized order. The interventions were preceded by a approximately 20-min rest period, consisted of 10 mins with or without WBV (26 or 0 Hz) with SS (40 degrees of knee flexion) or DS (55 degrees of knee flexion, at a cadence of 50 bpm) where SS+ and DS- were metabolically matched. Muscle (T(m)), core (T(c)), skin temperature (T(sk)), HR and VO(2) were recorded during each intervention. For T(m), there was a time (P<0.01) and WBV (P<0.01) effect but no squat effect was evident, and there was time xWBV interaction effect (P<0.01). In all four interventions, the work load was too low to cause cardiovascular stress. Instead normal, moderate physiological effects of exercise on autonomic control were observed as indicated by HR; there were no significant increases in T(sk) or T(c). There appears to be no benefit in performing an unloaded, shallow DS+ at a tempo of 50 bpm as T(m,) HR, VO(2) are likely to be increased by the same amount and rate without WBV. However, combining SS with WBV could be advantageous to rapidly increasing soft tissue temperature prior to performing rehabilitation exercises when dynamic exercise cannot be performed.

Vibration as an exercise modality: how it may work, and what its potential might be

Whilst exposure to vibration is traditionally regarded as perilous, recent research has focussed on potential benefits. Here, the physical principles of forced oscillations are discussed in relation to vibration as an exercise modality. Acute physiological responses to isolated tendon and muscle vibration and to whole body vibration exercise are reviewed, as well as the training effects upon the musculature, bone mineral density and posture. Possible applications in sports and medicine are discussed. Evidence suggests that acute vibration exercise seems to elicit a specific warm-up effect, and that vibration training seems to improve muscle power, although the potential benefits over traditional forms of resistive exercise are still unclear. Vibration training also seems to improve balance in sub-populations prone to fall, such as frail elderly people. Moreover, literature suggests that vibration is beneficial to reduce chronic lower back pain and other types of pain. Other future indications are perceivable.

The effects of a whole-body vibration program on muscle performance and flexibility in female athletes

OBJECTIVE

This randomized controlled study was designed to investigate the short-term effects of an 8-wk whole-body vibration protocol on muscle performance and flexibility in female competitive athletes.

DESIGN

Twenty-six young volunteer female athletes (ages 21-27 yrs) were randomized to either the vibration group or control group. The vibration intervention consisted of an 8-wk whole-body vibration 3 times a week employed by standing on a vertical vibration platform. As outcome measures, three performance tests (counter-movement jump, extension strength of lower extremities with an isokinetic horizontal leg press, and a sit-and-reach test for flexibility) were performed initially and after 8 wks.

RESULTS

A total of 24 athletes completed the study properly. In the vibration group (n = 13) whole-body vibration induced significant improvement of bilateral knee extensor strength (P < 0.001), counter-movements jump (P < 0.001), and flexibility (P < 0.001) after 8 wks of training. No significant changes were found for all the outcome measures for the control group (n = 11).

CONCLUSIONS

Whole-body vibration is a suitable training method to improve knee extension maximal strength, counter-movement jump, and flexibility in a young female athlete if it is properly designed. Not only do the optimal frequency, amplitude, and g-forces need to be identified but also the level of muscle activation that would benefit more from vibration stimulation. The improvement of flexibility is important not only for performance but also for the prevention of muscle-tendon injury.

A portable vibrator for muscle performance enhancement by means of direct muscle tendon stimulation

Combining vibration stimulation with conventional resistance training has gained in popularity. However, no portable vibrator capable of directly stimulating muscle tendon appears to feature in the literature. The aim of this study was the development of such a unit. The unit developed makes use of a rotating eccentric mass system to produce desired amplitude and frequency range capable of investigating the diverse vibration characteristics used in previous research studies. The effects of strapping force, joint angle and day-to-day repeatability on these vibration characteristics were investigated. In addition, muscle electromyography (EMG) activity was subsequently used to identify the optimum vibration amplitude and frequency. Finally, the repeatability of these EMG responses and effect of joint angle were examined. The unit was able to produce desired vibration characteristics (amplitude: 0.2-2 mm; frequency: 30-200 Hz). Test day, strapping force and joint angle had no significant effect on these characteristics (p>0.05). Both amplitudes (0.5 and 1.2 mm) and all three frequencies (30, 65 and 100 Hz) tested, significantly enhanced EMG activity (p<0.05), with 1.2 mm and both 65 and 100 Hz resulting in significantly greater enhancements (p<0.05). Joint angle had no significant effect on these EMG results (p>0.05). The day-to-day repeatability of EMG response was shown to be high (r=0.76-0.90).

Acute and residual effects of vibratory stimulation on explosive strength in elite and amateur athletes

Fourteen elite and 14 amateur athletes were subjected to vibratory stimulation during bilateral biceps curl exercises of explosive strength exertion. The athletes performed two separate series of three sets of exercises in random order. The second set of one series was administered with superimposed vibration of 44 Hz and an acceleration of about 30 m x s(-2) transmitted through the two-arms handle to the arm muscles. The mechanical power of each repetition was measured by the 'Power Teach' instrument. The maximal and mean power values for each set were automatically recorded and shown on the screen. The acute effect was evaluated as the difference between the mean and peak power output in the second (with vibratory stimulation) and first (without vibratory stimulation) sets. Similarly, the residual effect was taken to be the difference between the power values of the third (after vibratory stimulation) and the first (before vibratory stimulation) sets. The results were subjected to a repeated-measures analysis of variance with group as a between-participants factor. The results showed that exercise mode (with vs without vibratory stimulation) resulted in a significant immediate effect for mean power and for maximal power. The factor group (elite vs amateurs) resulted in a significant effect for maximal power only. The increase in explosive strength exertion attributed to vibratory stimulation was 30.1 and 29.8 W (10.4% and 10.2%) for maximal and mean power respectively in the elite group, and 20.0 and 25.9 W (7.9% and 10.7%) respectively in the amateur athletes. Vibratory stimulation resulted in an insignificant residual effect.

The physioacoustic method and the creative process

This study investigated the physioacoustic chair's, i.e., an application of low-frequency sound waves, possible psychological effects with respect to deductive thinking and creativity as well as its possible effect on heart rate. Subjects, 21 men and 21 women, were randomly assigned in equal numbers to three groups: a control group, a placebo group, i.e., a group who believed that they underwent a physioacoustic treatment program which they however did not undergo, and a physioacoustic treatment group. After manipulation, subjects were required to take three psychological tests (measuring fluency and originality, preconscious thinking, and deductive thinking) in random order. During the entire experiment, subjects' heart rates were registered every minute. Analysis showed no significant differences among the groups with respect to psychological effects or to heart rate. The results were interpreted to mean that the physioacoustic chair provides a form of relaxation which does not produce effects on the creative process.