Effect of plantar vibration stimuli on the balance of older women: a randomized controlled trial

What are the temporal and physical characteristics of locally applied vibration that modulate balance in older adults? - A systematic review of the literature

BACKGROUND

Compromised balance is known to contribute to falls, which are associated with increased morbidity and mortality for older adults. Evidence suggests that the application of local vibration to the lower limbs of older adults has the potential to modulate balance.

RESEARCH QUESTION

To identify the temporal and mechanical parameters of vibration applied locally to the lower limbs of older adults that modulate measures of balance, and to define the short- and long-term effects of vibration on balance in this population.

METHODS

The PRISMA 2020 guidelines were used to conduct a systematic search including the PUBMED, EMBASE, and Scopus databases to identify peer-reviewed literature where vibration was applied to the lower limbs of older adults to modulate balance. Data was extracted using a study-specific data extraction form and risk of bias assessed. Where possible, effect sizes were calculated.

RESULTS

Of 7777 records screened, ten randomised controlled trials and 43 prospective laboratory-based studies met the inclusion criteria. Vibration frequencies ranged from 1 to 272 Hz, most studies (n=41) used ≤100 Hz. Amplitude ranged from 0.2 to 3.0 mm, most studies (n=28) used ≤1 mm. Effects of short-term vibration (applied for seconds to hours) were measured during and/or immediately after application. Short-term suprathreshold perceived muscle/tendon vibration had a 'large' destabilising effect size on balance in healthy older adults, but little or no effect on older fallers. Short-term subthreshold vibration to the soles of the feet had a 'small' stabilising effect size. Suprathreshold muscle, tendon or sole vibration applied for 10-30 min over days to weeks improved balance measures, but most (8 of 10) had increased risk of bias.

SIGNIFICANCE

The heterogeneity of methodology, populations, and vibration and balance parameters precluded conclusions about the relative effects of lower limb vibration in older adults. However, these results suggest that the application of local vibration to the lower limbs of older adults can modulate balance in the short- and long-term.

The Effects of Vibratory and Acoustic Stimulations on Postural Control in Healthy People: A Systematic Review

Research on human posture and balance control has grown in recent years, leading to continued advances in their understanding. The ability to maintain balance is attributed to the interplay of the visual, vestibular, and somatosensory systems, although an important role is also played by the auditory system. The lack or deficit in any of these systems leads to a reduced stability that may be counterbalanced by the integration of all the remaining sensory information. Auditory and vibratory stimulation have been found to be useful to enhance balance alongside daily activities either in healthy or pathological subjects; nevertheless, while widely investigated, the literature relating to these approaches is still fragmented. This review aims at addressing this by collecting, organising, and discussing all the literature to date on the effects of the various acoustic and vibratory stimulation techniques available on static upright posture in healthy subjects. In addition, this review intends to provide a solid and comprehensive starting point for all the researchers interested in these research areas. A systematic search of the literature was performed and a total of 33 articles (24 on vibratory stimulation and 9 on acoustic stimulation) were included in our analysis. For all articles, several elements were highlighted including: the study sample, the characteristics of the stimulations, the recording instruments, the experimental protocols, and outcomes. Overall, both stimulations analysed were found to have a positive effect on balance but more research is needed to align those alternative approaches to the traditional ones.

A Standing Low-frequency Vibration Exercise Device for Improving Balance in Community-dwelling Older Adults: A Single-blind Randomized Controlled Trial

OBJECTIVE

This study aimed to compare the effects of the standing low-frequency vibration exercise device (SLVED) and walking training on balance ability on an unstable surface in community-dwelling elderly people.

METHODS

Thirty-eight older adults were randomly allocated to the SLVED sessions: the intervention group (n = 19), and the walking sessions: the control group (n = 19). Each group session lasted 20 min and was performed twice a week for 12 weeks. Standing balance was assessed by the change in center-of-gravity sway of the participant standing on foam rubber with eyes open (EO) and eyes closed (EC). The primary outcome measures were the root mean square (RMS) values of the center of foot pressure in the mediolateral and anteroposterior directions and the RMS area. Secondary outcome measures were the results of the 10-m walking time test (10 MWT), five-times sit-to-stand (5T-STS) test, and timed up-and-go (TUG) test.

RESULTS

Analysis of variance showed a significant group × time interaction for the TUG test. Significant improvements were observed in Y-RMS for EO condition; RMS, X-RMS, Y-RMS, and RMS area for EC condition; and 10 MWT, 5T-STS test, and TUG test for the main effect of the time factor.

CONCLUSION

SLVED for intervention in community-dwelling older adults showed a greater improvement than walking training in the TUG test. In addition, SLVED improved the Y-RMS for the EO condition on foam rubber; RMS, X-RMS, Y-RMS, and RMS area for the EC condition on foam rubber in standing balance; and the 10 MWT and 5T-STS test, suggesting that it has similar effects to walking training.

The Effect of Human Settlement Pedestrian Environment on Gait of Older People: An Umbrella Review

Older people are limited by the pedestrian environment in human settlements and are prone to travel difficulties, falls, and stumbles. Furthermore, we still lack systematic knowledge of the pedestrian environment affecting the gait of older people. The purpose of this review is to synthesize current evidence of effective human settlement pedestrian environments interfering with gait in older people. The systematic effects of the human settlement pedestrian environment on gait in older people are discussed. Databases such as Web of Science, Medline (via PubMed), Scopus, and Embase were searched for relevant studies up to June 2022. The literature was screened to extract relevant evidence from the included literature, assess the quality of the evidence, and analyze the systematic effects of the pedestrian environment on gait in older people. From the 4297 studies identified in the initial search, 11 systematic reviews or meta-analysis studies were screened, from which 18 environmental factors and 60 gait changes were extracted. After removing duplicate elements and merging synonymous features, a total of 53 relationships between environmental factors and gait change in older people were extracted: the main human settlement pedestrian environmental factors affecting gait change in older people in existing studies were indoor and outdoor stairs/steps, uneven and irregular ground, obstacles, walking path turns, vibration interventions, mechanical perturbation during gait, and auditory sound cues. Under the influence of these factors, older people may experience changes in the degree of cautiousness and conservatism of gait and stability, and their body posture performance and control, and muscle activation may also be affected. Factors such as ground texture or material, mechanical perturbations during gait, and vibration interventions stimulate older people's understanding and perception of their environment, but there is controversy over the results of specific gait parameters. The results support that human settlements' pedestrian environment affects the gait changes of older people in a positive or negative way. This review may likely contribute evidence-based information to aid communication among practitioners in public health, healthcare, and environmental construction. The above findings are expected to provide useful preference for associated interdisciplinary researchers to understand the interactions among pedestrian environments, human behavior, and physiological characteristics.

The Focal Mechanical Vibration for Balance Improvement in Elderly - A Systematic Review

Background

Aging has been associated with the progressive depletion of lean mass, reductions in muscle strength and the coordination of the lower extremities, accompanied by decreased gait assurance and balance control. Also, less balance control favors falling which is the leading cause of injury among the elderly. The aim of this systematic review is to identify and evaluate existing evidence regarding the use of focused vibration (FV) to improve balance and reduce the risk of falling during the rehabilitation of elderly populations.

Methods

The PICO question is what are the effects of focal/segmental/local vibration training on the assessment of balance and the risk of falls among the elderly population? A thorough literature review was conducted between May 1, 2009, and June 30, 2019, for studies in English, randomized clinical trials, including crossover and prospective design studies with assessing balance and the risk of falls in elderly populations (age > 60 years).

Results

Eight articles (N = 8) satisfied the inclusion criteria and were considered, of which 6 are RTC, one cross-sectional study and one clinical study, for a total of 635 participants. A total of 6 different vibration devices were used, each of which was associated with different FV frequency and amplitude characteristics and different treatment protocols.

Conclusion

In conclusion, FV can be effective in decreasing the risk of falls and improving the assessment of balance, but more evidence is necessary considering the limits of the studies; however, it does look an important promise during rehabilitative treatment.

Immediate Effects of Plantar Vibration on Fall Risk and Postural Stability in Stroke Patients: A Randomized Controlled Trial

BACKGROUND

Local vibration can improve balance problems of individuals with stroke when applied to the plantar region.

AIMS

This study aimed to determine the immediate effect of local vibration applied to the plantar region on fall risk and postural stability in patients with stroke.

STUDY DESIGN

Randomized controlled study.

METHODS

30 patients (23 male,7 female) with stroke were randomized to either vibration (n = 15; 58.47 ± 8.23 years) or control (n = 15; 58.27 ± 9.50 years) groups. Before and after the intervention, the patients were evaluated using a Biodex Balance System. Local vibration was applied to the plantar region of two feet in the supine position using a vibration device for a total of 15 min to the individuals in the vibration group. While the patients in the placebo group were in the supine position, the device was brought into contact and no vibration was applied to the plantar region of two feet for 15 min.

RESULTS

While significant improvements were observed in the postural stability and fall risk of the vibration group (p < 0.05), no significant change was observed in the placebo group (p > 0.05). Furthermore, significant improvements occurred in the SD values of the postural stability expressing postural oscillation in the vibration group (p < 0.05).

CONCLUSION

As a result of local vibration applied to the plantar region, immediate (within 5 min) significant improvements in postural stability and fall risk values were detected.

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.

Immediate effects of plantar vibration stimuli during static upright posture following total hip arthroplasty in females

PURPOSE

Proprioceptive function of the lower limbs deteriorates in patients following total hip arthroplasty. Patients show poor balance and rely more on visual information than proprioceptive information. Plantar vibration stimuli can mechanically enhance somatosensory input from the plantar cutaneous mechanoreceptors, thereby improving static balance. Plantar vibration stimuli may improve static balance in patients after total hip arthroplasty. This is the first study to investigate whether plantar vibration stimuli affects static balance during the early phase following total hip arthroplasty.

MATERIALS AND METHODS

In this cross-over design study, 16 female patients (aged 65.1 ± 11.0 years) received plantar vibration stimuli for 2 minutes or the sham interventions after total hip arthroplasty in a randomized order on different days. The foot centre of pressure was measured for the total path length, mediolateral path length, and anteroposterior path length directions before and immediately after the interventions in the static standing position both with eyes open and closed. Patients were instructed to minimize body sway when standing.

RESULTS

A significant increase was observed in the centre of pressure parameters in the eyes closed condition than in the eyes open condition. The centre of pressure parameters for the eyes closed condition was significantly decreased after vibration interventions than that before intervention.

CONCLUSIONS

This study supports the view that plantar vibration stimuli can change static balance in patients in the early phase after total hip arthroplasty temporarily by up-weighting sensory information. These stimuli may serve as a treatment option for influencing balance following total hip arthroplasty.

Effect of vibration on postural control and gait of elderly subjects: a systematic review

BACKGROUND AND AIM

Gait and balance disorders are common in the elderly populations, and their prevalence increases with age. This systematic review was performed to summarize the current evidence for subthreshold vibration interventions on postural control and gait in elderly.

METHOD

A review of intervention studies including the following words in the title/abstract: insole, foot and ankle appliances, vibration, noise and elderly related to balance and gait. Databases searched included PubMed, ISI Web of Knowledge, Ovid, Scopus, and Google Scholar. Fifteen articles were selected for final evaluation. The procedure was followed using the preferred reporting items for systematic reviews and meta-analysis method.

RESULTS

There was reduction in center of pressure velocity and displacement especially with eyes closed using vibration in healthy elderly subjects and this effect was greater in elderly faller and patients with more balance deficiency. Vibration programme training increased speed of walking, cadence, step time and length in stroke subjects. The vibratory insoles significantly improved performance on the Timed Up and Go and Functional Reach tests in older people.

CONCLUSION

Vibration was effective on balance improvement in elderly subject especially elderly with more balance deficiency and it can improve gait parameters in patients with greater baseline variability.

A clinical single blind study to investigate the immediate effects of plantar vibration on balance in patients after stroke

Balance disorder is a very common cause of disability in patients after a stroke. Vibration therapy is one of the physiotherapeutic modalities used to improve balance.

OBJECTIVE

To investigate the immediate effects of plantar vibration on balance in patients with stroke.

METHODS

In this single blind comparative study, 22 patients with stroke (8 females, 14 males; age 55.82 ± 11.87 years old) participated. Patients underwent treatment, first with the placebo vibration and 1 week later with active vibration (frequency 100 HZ, 5 min). Mini-BESTest score, Modified Modified Ashworth Scale for plantar flexor spasticity, and ankle dorsiflexion passive range of motion (PROM) were evaluated before and immediately after the placebo or active vibration.

RESULTS

A significant clinical improvement in balance, ankle plantar flexor spasticity, and the ankle dorsiflexion PROM was observed following either placebo or active vibration. The improvements after active vibration were significantly greater for all outcome measures compared with placebo vibration. There was a large effect size (Cohen's d = 0.85) for balance after active vibration.

CONCLUSION

The vibration applied to the sole of the affected foot of patients after stroke was effective for improving balance, reducing ankle plantar flexor spasticity, and increasing ankle dorsiflexion PROM.

A study on the immediate effects of plantar vibration on balance dysfunction in patients with stroke

The aim of this study was to estimate the immediate effects of plantar vibration, applied to the more affected foot, on balance impairment in patients post-stroke. This pretest-posttest clinical study included 18 patients (13 men) poststroke; mean age 56.0±8.9 years (range, 41-71 years). One session of 5-min vibratory stimuli (frequency, 100 Hz) was applied to the plantar region of the more affected foot of all participants. The plantar vibration significantly improved the Timed UP and Go test (P=0.03, Cohen d=0.15), ankle plantar flexor muscle spasticity (P=0.008), and ankle passive range of motion (P<0.001, Cohen d=0.74). The posturography measures and Functional Reach Test did not improve significantly (P>0.05). Vibration stimuli applied to the plantar region of the more affected foot had significant effects on spasticity, ankle passive range of motion and dynamic balance as evaluated by the Timed Up and Go test in patients poststroke. There was no effect on static balance performance. Based on the results, the focal vibratory stimuli applied directly to the plantar region of the more affected foot may be recommended to improve the functional mobility and dynamic balance in patients with stroke.

A systematic review of the effect of foot orthoses and shoe characteristics on balance in healthy older subjects

BACKGROUND

Foot orthoses are used to optimize lower extremity function and can improve postural stability by enhancing the afferent somatosensory feedback available to the central nervous system.

OBJECTIVE

The aim of this review was to evaluate the effect of foot orthoses on balance control in older subjects.

STUDY DESIGN

Systematic review.

METHODS

The search strategy was based on the Population Intervention Comparison Outcome method. A search was performed in PubMed, Science Direct, Google Scholar, and ISI Web of Knowledge databases by using selected keywords. A total of 22 articles were selected for final evaluation.

RESULTS

The results demonstrated that older people should be advised to wear thin, hard-soled footwear with high collars to reduce the risk of falling. The findings for insoles demonstrated an increase in balance control via vibratory or magnetic insoles, but textured insoles do not appear to be beneficial for balance improvement.

CONCLUSION

Foot orthoses improve postural stability via a somatosensory or biomechanical effect. Use of footwear with the proper features can be an appropriate intervention in order to increase the balance in the older population and reduce falls.

CLINICAL RELEVANCE

Loss of balance is an important factor in increasing the risk of falling in older subjects. Foot orthoses can improve functional measures of stability in older adults. In this review, results from studies suggest a number of recommendations regarding the optimal footwear for older people to reduce the risk of falling.

Effects of vibratory training on plantar impression in patients affected by stroke

Aim:

The aim of this study was to investigate the effect of vibration training on plantar impression and motor function in patients affected by stroke.

Methods:

The sample consisted of 28 individuals with hemiparesis after stroke who were randomly assigned to the intervention group (n=18) and the control group (n=10). The instruments used for evaluation were the mini-mental state examination, photopodoscopy and the 6-minute walk test. For treatment, whole body vibration training was used three times a week for 8 weeks. The treatment was carried out in two phases. The first phase, which lasted for 4 weeks, consisted of four sets of exercises with 60 seconds of vibration. In the first exercise, the participants were in a static standing position, feet apart with knees flexed at 30°. In the second exercise, the same position was implemented, with knees flexed at 90°. In the third exercise, a standing position with one-leg support on the affected limb with flexed knee at 30°. The fourth exercise was a repetition of the first exercise. The second phase also lasted for 4 weeks. It consisted of the same exercises but the amount of sets of exercises was doubled.

Results:

Data were analysed by independent t-test and repeated measures ANOVA with two factors. There was no intergroup nor intragroup statistical difference (P=0.05) in the plantar impression area on the affected and unaffected side; there was only intragroup statistical differences in the 6-minute walk test (P=0.03).

Conclusions:

Whole-body vibration training did not influence the increase of the plantar impression area and motor function in stroke patients.

Changes in postural sway according to footwear types of hemiparetic stroke patients

[Purpose] The purpose of the current study was to investigate the influence of footwear type on postural sway of hemiparetic stroke patients. [Subjects] Thirty-two stroke patients who were undergoing a rehabilitation program were recruited on a voluntary basis from local rehabilitation unit. [Methods] This study had a single-group repeated-measures design. The Good Balance system was used to measure the postural sway velocity (anteroposterior and mediolateral) and velocity moment of the subjects under the eyes open and eyes closed conditions in the standing posture. Postural sway of the subjects in four types of footwear was measured, including barefoot, high heel-collar shoes, flat shoes, or slippers. [Results] The postural sway when wearing the flat shoes or slippers was significantly higher than that when barefoot or wearing high heel-collar shoes. In addition, postural sway velocity and velocity moment of all the footwear types were significantly higher under the eyes closed condition than under the eyes open condition. [Conclusion] Our results reveal that when the subjects wore flat shoes or slippers they had more difficulty than when they wore the high heel-collar shoes in postural control when maintaining standing balance. We believe that this result provides basic information for improvements in postural control and may be useful in balance training to prevent falls after stroke.

Decreased skin temperature of the foot increases gait variability in healthy young adults

We investigated the effects of reduction in plantar skin temperature on gait. Thirty-four healthy subjects (20 men and 14 women; mean age 22.2±2.5 years; mean height 166.8±8.3cm) walked 16m under two different conditions - normal conditions (NC) with the skin at a basal temperature, and cold conditions (CC) after cooling of the plantar skin to about 15°C. Wireless motion-recording sensor units were placed on the back at the level of L3 and on both heels to measure acceleration and angular velocity. Gait velocity and mean stride, stance and swing times were calculated. The variability of lower limb movement was represented by the coefficients of variation (CVs) of stride, stance and swing times, and that of trunk movement was represented by autocorrelation coefficients (ACs) in three directions (vertical: VT; mediolateral: ML; and anteroposterior: AP). Gait velocity was significantly lower under CC conditions than under NC (p<0.0001). None of the temporal parameters were changed by plantar cooling. However, all parameters of gait variability were significantly worse under CC, and AC-VT, AC-ML, and AC-AP were significantly lower under CC than under NC, even after adjusting for gait velocity (p=0.0005, 0.0071, and 0.0126, respectively). Our results suggest that reducing plantar skin temperature induces gait variability among healthy young adults. Further studies are now needed to explore the relationship between plantar skin temperature and gait in the elderly.

Effect of a local vibration stimulus training programme on postural sway and gait in chronic stroke patients: a randomized controlled trial

Objective:

To investigate the effect of a local vibration stimulus training programme on postural sway and gait in stroke patients.

Design:

A randomized controlled trial with two groups: a local vibration stimulus training programme group and a sham group.

Setting:

Inpatient rehabilitation centre.

Subjects:

Thirty-one chronic stroke patients.

Interventions:

Both groups underwent a standard rehabilitation programme. The local vibration stimulus training programme group ( n = 16) participated in the local vibration stimulus training programme for 30 minutes a day, five times a week, for six weeks. The sham group ( n = 15) participated in a sham local vibration stimulus training programme for 30 minutes a day, five times a week, for six weeks.

Main measures:

A forceplate was used to measure postural sway under two conditions: standing with eyes open and eyes closed. Gait ability was measured using the GAITRite system.

Results:

In postural sway, greater improvements in the postural sway distance with eyes-open (–11.91 vs. 0.80) and eyes-closed (–20.67 vs. –0.34) conditions and postural sway velocity with eyes-open (–0.40 vs. 0.03) and eyes-closed (–0.69 vs. –0.01) conditions were observed in the local vibration stimulus training programme group, compared with the sham group ( P < 0.05). In gait ability, greater improvement in gait speed (15.06 vs. 2.85), cadence (8.46 vs. 1.55), step length (7.90 vs. 3.64), and single limb support time (0.12 vs. 0.01) were observed in the local vibration stimulus training programme group, compared with the sham group ( P < 0.05).

Conclusions:

These findings suggest that local vibration stimulus training programme is an effective method for improvement of the postural sway and gait ability of chronic stroke patients.