Textured shoe insoles to improve balance performance in adults with diabetic peripheral neuropathy: study protocol for a randomised controlled trial

The effects of vibrating shoe insoles on standing balance, walking, and ankle-foot muscle activity in adults with diabetic peripheral neuropathy

BACKGROUND

Peripheral neuropathy is one of the most common complications of type 2 diabetes, which can lead to impaired balance and walking. Innovative footwear devices designed to stimulate foot sensory receptors, such as vibrating insoles, could offer a new route to improve motor impairments in people with diabetic peripheral neuropathy (DPN).

RESEARCH QUESTION

Does wearing vibrating insoles for the first time alter measures of balance, walking, and ankle-foot muscle activity, in people with DPN?

METHODS

A randomised cross-over study was conducted with 18 ambulant men and women with a diagnosis of DPN. Participants performed tests of standing balance (Bertec® force platform) under four conditions (foam/firm surface, eyes open/closed) and level-ground walking (GAITRite® instrumented walkway), whilst wearing vibrating and non-vibrating (control) insoles on two separate occasions (one insole/session). Electromyography (EMG) was used to assess soleus, medial gastrocnemius, tibialis anterior, peroneus longus activity during balance tests. Outcomes included centre of pressure (CoP) sway, EMG amplitude, spatiotemporal gait patterns, and Timed Up and Go test. One sample t-tests were used to explore %differences in outcomes between insole conditions.

RESULTS

Wearing vibrating insoles led to a reduction (improvement) in CoP elliptical area, when standing on a foam surface with eyes closed, relative to non-vibrating insoles (P=0.03). Applying perceptible vibrations to the soles of the feet also reduced the EMG amplitude in soleus (P=0.01 and P=0.04) and medial gastrocnemius (P=0.03 and P=0.09) when standing with eyes closed on firm and foam surfaces.

SIGNIFICANCE

Our findings of signs of improved balance and altered muscle activity with suprasensory vibrating insoles provides new insights into how these devices can be used to inform innovative rehabilitation approaches in individuals with DPN. This will be strengthened by further research into possible clinical benefits of these devices - given that the effects we detected were small with uncertain clinical meaning.

The effects of wearing textured versus smooth shoe insoles for 4-weeks in people with diabetic peripheral neuropathy: a randomised controlled trial

PURPOSE

To determine whether short-term wear of textured insoles alters balance, gait, foot sensation, physical activity, or patient-reported outcomes, in people with diabetic neuropathy.

MATERIALS AND METHODS

53 adults with diabetic neuropathy were randomised to wear textured or smooth insoles for 4-weeks. At baseline and post-intervention, balance (foam/firm surface; eyes open/closed) and walking were assessed whilst barefoot, wearing shoes only, and two insoles (textured/smooth). The primary outcome was center of pressure (CoP) total sway velocity. Secondary outcomes included other CoP measures, spatiotemporal gait measures, foot sensation, physical activity, and patient-reported outcomes (foot health, falls efficacy).

RESULTS

Wearing textured insoles led to improvements in CoP measures when standing on foam with eyes open, relative to smooth insoles (p ≤ 0.04). The intervention group demonstrated a 5% reduction in total sway velocity, indicative of greater balance. The intervention group also showed a 9-point improvement in self-perceived vigour (p = 0.03). Adjustments for multiple comparisons were not applied.

CONCLUSIONS

This study provides weak statistical evidence in favour of textured insoles. Wearing textured insoles may alter measures of balance, suggestive of greater stability, in people with diabetic neuropathy. Plantar stimulation, through textured insoles, may have the capacity to modulate the perception of foot pain, leading to improved well-being.IMPLICATIONS FOR REHABILITATIONShort-term wear of textured insoles can lead to improvements in centre of pressure sway measures when standing on a compliant supporting surface.Wearing textured insoles may have the capacity to help relieve foot pain leading to enhanced self-perceived vitality in people with diabetic peripheral neuropathy.

Environmental interventions for preventing falls in older people living in the community

BACKGROUND

Falls and fall-related injuries are common. A third of community-dwelling people aged over 65 years fall each year. Falls can have serious consequences including restricting activity or institutionalisation. This review updates the previous evidence for environmental interventions in fall prevention.

OBJECTIVES

To assess the effects (benefits and harms) of environmental interventions (such as fall-hazard reduction, assistive technology, home modifications, and education) for preventing falls in older people living in the community.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, other databases, trial registers, and reference lists of systematic reviews to January 2021. We contacted researchers in the field to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials evaluating the effects of environmental interventions (such as reduction of fall hazards in the home, assistive devices) on falls in community-residing people aged 60 years and over.   DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Our primary outcome was rate of falls.

MAIN RESULTS

We included 22 studies from 10 countries involving 8463 community-residing older people. Participants were on average 78 years old, and 65% were women. For fall outcomes, five studies had high risk of bias and most studies had unclear risk of bias for one or more risk of bias domains. For other outcomes (e.g. fractures), most studies were at high risk of detection bias. We downgraded the certainty of the evidence for high risk of bias, imprecision, and/or inconsistency.  Home fall-hazard reduction (14 studies, 5830 participants) These interventions aim to reduce falls by assessing fall hazards and making environmental safety adaptations (e.g. non-slip strips on steps) or behavioural strategies (e.g. avoiding clutter).  Home fall-hazard interventions probably reduce the overall rate of falls by 26% (rate ratio (RaR) 0.74, 95% confidence interval (CI) 0.61 to 0.91; 12 studies, 5293 participants; moderate-certainty evidence); based on a control group risk of 1319 falls per 1000 people a year, this is 343 (95% CI 118 to 514) fewer falls. However, these interventions were more effective in people who are selected for higher risk of falling, with a reduction of 38% (RaR 0.62, 95% CI 0.56 to 0.70; 9 studies, 1513 participants; 702 (95% CI 554 to 812) fewer falls based on a control risk of 1847 falls per 1000 people; high-certainty evidence). We found no evidence of a reduction in rate of falls when people were not selected for fall risk (RaR 1.05, 95% CI 0.96 to 1.16; 6 studies, 3780 participants; high-certainty evidence). Findings were similar for the number of people experiencing one or more falls. These interventions probably reduce the overall risk by 11% (risk ratio (RR) 0.89, 95% CI 0.82 to 0.97; 12 studies, 5253 participants; moderate-certainty evidence); based on a risk of 519 per 1000 people per year, this is 57 (95% CI 15 to 93) fewer fallers. However, for people at higher risk of falling, we found a 26% decrease in risk (RR 0.74, 95% CI 0.65 to 0.85; 9 studies, 1473 participants), but no decrease for unselected populations (RR 0.99, 95% CI 0.92 to 1.07; 6 studies, 3780 participants) (high-certainty evidence). These interventions probably make little or no important difference to health-related quality of life (HRQoL) (standardised mean difference 0.09, 95% CI -0.10 to 0.27; 5 studies, 1848 participants; moderate-certainty evidence). They may make little or no difference to the risk of fall-related fractures (RR 1.00, 95% 0.98 to 1.02; 2 studies, 1668 participants), fall-related hospitalisations (RR 0.96, 95% CI 0.87 to 1.06; 3 studies, 325 participants), or in the rate of falls requiring medical attention (RaR 0.91, 95% CI 0.58 to 1.43; 3 studies, 946 participants) (low-certainty evidence). The evidence for number of fallers requiring medical attention was unclear (2 studies, 216 participants; very low-certainty evidence). Two studies reported no adverse events. Assistive technology Vision improvement interventions may make little or no difference to the rate of falls (RaR 1.12, 95% CI 0.84 to 1.50; 3 studies, 1489 participants) or people experiencing one or more falls (RR 1.09, 95% CI 0.79 to 1.50) (low-certainty evidence). We are unsure of the evidence for fall-related fractures (2 studies, 976 participants) and falls requiring medical attention (1 study, 276 participants) because the certainty of the evidence is very low. There may be little or no difference in HRQoL (mean difference 0.40, 95% CI -1.12 to 1.92) or adverse events (falls while switching glasses; RR 1.00, 95% CI 0.98 to 1.02) (1 study, 597 participants; low-certainty evidence). Results for other assistive technology - footwear and foot devices, and self-care and assistive devices (5 studies, 651 participants) - were not pooled due to the diversity of interventions and contexts.  Education  We are uncertain whether an education intervention to reduce home fall hazards reduces the rate of falls or the number of people experiencing one or more falls (1 study; very low-certainty evidence). These interventions may make little or no difference to the risk of fall-related fractures (RR 1.02, 95% CI 0.96 to 1.08; 1 study, 110 participants; low-certainty evidence).  Home modifications We found no trials of home modifications that measured falls as an outcome for task enablement and functional independence.

AUTHORS' CONCLUSIONS

We found high-certainty evidence that home fall-hazard interventions are effective in reducing the rate of falls and the number of fallers when targeted to people at higher risk of falling, such as having had a fall in the past year and recently hospitalised or needing support with daily activities. There was evidence of no effect when interventions were targeted to people not selected for risk of falling. Further research is needed to examine the impact of intervention components, the effect of awareness raising, and participant-interventionist engagement on decision-making and adherence.  Vision improvement interventions may or may not impact the rate of falls. Further research is needed to answer clinical questions such as whether people should be given advice or take additional precautions when changing eye prescriptions, or whether the intervention is more effective when targeting people at higher risk of falls. There was insufficient evidence to determine whether education interventions impact falls.

Neuromuscular response to the stimulation of plantar cutaneous during walking at different speeds

BACKGROUND

A lot of authors have been studied the consequence of postural control strategies through investigating the effects of foot-surface contact. In this context an important variable of textured surfaces or insoles could be related to material stiffness. We apply a particular textured insoles to evaluate neuromuscular response of plantar stimulation during walking.

RESEARCH QUESTION

Could textured insoles alter the human locomotion during walking at different speeds?

METHODS

Ten adults (age: 27 ± 5 years) completed three trials on the multifunction treadmill at 0.42 ms^-1, 0.89 ms^-1, and 1.5 ms^-1 walking speed. Temporal-spatial parameters, gait line, and kinetic parameters were analyzed. The Co-Contraction Index (CCI) and electromyography (EMG) of the right leg muscles were assessed during four phases of gait: first half stance (FHS), half stance (HS), second half stance (SHS), swing phase (SP). Textured insole and soft control insole were worn while walking.

RESULTS

Plantar stimulation improved cadence, stride time, stride length and gait line parameters with increasing speed. First force peaks and maximum force forefoot were always significant. The maximum force midfoot was significant at 0.42 and 0.89 ms^-1. The maximum force heel only was significant in lower velocity. The maximum pressure showed different significant values except for the heel. Significant differences in the CCI were always found in the FHS and SHS for the plantar muscles, and in the FHS and HS for the knee muscles. The differences in gait analysis in biomechanical and in electromyographic parameters were more significant in the higher speed tested.

SIGNIFICANCE

The perception of shape and texture through its linear response to skin deformation over a wide range of deformations could be the reason why the significant differences increase in the higher speed. In conclusion, sensory interventions fallowing appropriate insoles can influence significantly gait. Walking strategy positively adjusts locomotion with high efficiency.

The Influence of Walking Height and Width on the Gait

Walking stability is an important factor that is related to working accidents at height. The understanding of the relationship between walking stability and walking conditions remains an unmet need. Therefore, this study aimed to investigate the effect of path height, width, and asymmetric conditions on the pressure and time information of the foot-ground interaction during walking. 12 subjects were required to walk at two height, three width, and asymmetric conditions. Plantar pressures during walking were measured with the F-scan insole sensors. The total pressures were normalized with body weight, and the temporal parameters were normalized with stance time. When the walking height increased, the plantar pressure at the "heel strike" phase did not change significantly, while that at "heel rise" and "toe off" phases significantly increased, and the "heel rise" occurred earlier, indicating a greater foot-ground interaction at the forefoot part of the sole. As the path width increased from 0.6 m to 1.2 m, the foot-ground interaction as well as the asymmetric effect approached to that of overground walking. The findings could help improve the risk assessment and footwear design.

Can Insoles Be Used to Improve Static and Dynamic Balance of Community-Dwelling Older Adults? A Systematic Review on Recent Advances and Future Perspectives

This systematic review investigated the effects of orthopedic, vibrating, and textured insoles on the postural balance of community-dwelling older adults. Articles published in English from 1999 to 2019 investigating the effects of (a) orthopedic, (b) vibrating, and (c) textured insoles on static and dynamic balance in community-dwelling older adults were considered. Twenty-four trials with a total of 634 older adults were identified. The information gathered generally supported the balance-improving effects of orthopedic, vibrating, and textured insoles in both static and dynamic conditions among community-dwelling older adults. Further examination found that rigidity, texture patterns, vibration thresholds, and components like arch supports and heel cups are important factors in determining whether insoles can improve balance. This review highlights the potential of insoles for improving the static and dynamic balance of community-dwelling older adults. Good knowledge in insole designs and an understanding of medical conditions of older adults are required when attempts are made to improve postural balance using insoles.