Differences in foot sensitivity and plantar pressure between young adults and elderly

Enhancing lower-limb motor imagery using a paradigm with visual and spatiotemporal tactile synchronized stimulation

Objective.Vibrotactile stimulation (VS) has been widely used as an appropriate motor imagery (MI) guidance strategy to improve MI performance. However, most VS induced by a single vibrator cannot provide spatiotemporal information of tactile sensation associated with the visual guidance of the imagined motion process, not vividly providing MI guidance for subjects.Approach.This paper proposed a paradigm with visual and spatiotemporal tactile synchronized stimulation (VSTSS) to provide vivid MI guidance to help subjects perform lower-limb MI tasks and improve MI-based brain-computer interface (MI-BCI) performance, with a focus on poorly performing subjects. The proposed paradigm provided subjects with the natural spatiotemporal tactile sensation associated with the visual guidance of the foot movement process during MI. Fourteen healthy subjects were recruited to participate in the MI and Rest tasks and divided into good and poor performers. Furthermore, electrophysiological features and classification performance were analyzed to assess motor cortical activation and MI-BCI performance under no VS (NVS), VS, and VSTSS.Main results.The phenomenon of event-related desynchronization (ERD) in the sensorimotor cortex during MI under the VSTSS was more pronounced compared to the NVS and VS. Specifically, the VSTSS could improve the average ERD values in the motor cortex during the task segment by 34.70% and 14.28% than the NVS and VS in the alpha rhythm for poor performers, respectively. Additionally, the VSTSS could significantly enhance the classification accuracy between the MI and Rest tasks by 12.52% and 4.05% compared to NVS and VS for poor performers, respectively.Significance.The proposed paradigm could enhance motor cortical activation during MI and improve classification performance by providing vivid MI guidance for subjects, offering a promise for the application of lower-limb MI-BCI in stroke rehabilitation in the future.

Effect of plantar sensory exercises on balance and fall risk in nursing home elderly

BACKGROUND

Loss of balance and consequent falls are leading causes of mortality and morbidity in the geriatric population. In terms of ease of application, plantar sensory-based exercises seem to be superior to other balance development exercises. Our study's objective is to examine the effects of plantar sensation education-based exercises on balance and falls.

MATERIALS AND METHODS

16 healthy, voluntary nursing home residents with the average age 77.50 ± 5.5. Individuals had plantar sensory exercises 40 min sessions for 3 days/week during eight weeks. The study was planned as a self-controlled prospective study. Functional balance was evaluated using Berg Balance Scale, dynamic balance was evaluated using 30 Second Chair Stand Test, static balance and fall risk were assessed using Biodex Balnce System.

RESULTS

The measurements of static balance and fall tests with the Biodex balance device after 8 weeks of plantar sensation exercises program showed significant improvement compared to the results before the treatment (p < 0.05). The measurements of the Biodex balance device before the treatment were 3.45 ± 2.41, whereas the ones after the treatment showed 2.61 ± 2.18. The result of the fall risk measured by the Biodex balance device was 3.43 ± 3.11 before the treatment, whereas it came out as 2.46 ± 2.02 after the treatment. (p < 0.05) CONCLUSION: Static balance and fall risc play a significant role in the well-being of nursing home residents through exercise programs designed for plantar sensation. According to these outcomes, we believe that exercises intended for plantar sensation will be an effective treatment approach in terms of increasing the static balance and decreasing the fall risk with nursing home residents.

A feasibility study investigating cortical hemodynamic changes during infinity walk with fNIRS

This study seeks to explore the correlation between cortical activation and the Infinity Walk pattern, examining how the influence of foot overpronation and footwear may impact motor control. Functional near-infrared spectroscopy (fNIRS), a portable and user-friendly neuroimaging technique, was used to measure hemodynamical changes in six individuals with non-critical pronation degrees. Participants perform the Infinity Walk under various footwear conditions while wearing an fNIRS portable imaging device. Results indicate a consistent hemodynamic pattern in both hemispheres during the Infinity Walk, with no significant differences observed across subjects and footwear conditions in the prefrontal cortex (PFC), pre-motor area, the supplementary motor cortex (PMA & SMC), the primary motor cortex (PMC), and Wernicke's area (WA). The impact of pronation and footwear on motor control remains inconclusive due to inconsistent hemodynamic patterns. Notably, the activation patterns in Broca's area (BA) and the temporal gyrus (TG) differ significantly from other brain regions. The balanced hemodynamic responses in the bilateral hemispheres may be attributed to the Infinity Walk's inherent walking pattern. These findings indicate a need for further investigation into the Infinity Walk to examine the similarities and distinctions in activation patterns within specific brain regions. Additionally, the impact of pronation necessitates more substantial experimental research to establish a correlation between pronation and cortical hemodynamics.

Enhancing Footwear Safety for Fall Prevention in Older Adults: A Comprehensive Review of Design Features

BACKGROUND

Falls are a global concern affecting people of all ages; however, older adults are particularly vulnerable to age-related factors and foot-related issues. Footwear is critical for preventing falls, as it provides stability and protection against slips, trips, and falls (STFs). However, a significant gap exists in the systematic exploration of the safety aspects of footwear design for fall prevention in older adults.

METHODS

This comprehensive review applied a meticulous search strategy encompassing prominent databases, including Google Scholar, ScienceDirect, SCOPUS, MEDLINE, ResearchGate, and PubMed. This review synthesized and analyzed existing research to bridge knowledge gaps and provide insights into optimal footwear choices for older adults in terms of design features such as fit, fixation, heel height, collar height, slip resistance, and sole/insole hardness.

RESULTS

The results underscore the importance of specific design features for preventing falls among older adults. A proper fit, secure fixation, appropriate heel and collar heights, slip resistance, and sole/insole hardness significantly contributed to fall prevention. These findings offer valuable guidance for optimizing footwear designs to enhance comfort, stability, and safety in the daily lives of older individuals.

CONCLUSION

This comprehensive review fills a critical knowledge gap regarding the safety of footwear designs for fall prevention in older adults. The identified design features play a vital role in reducing the risk of falls and offer practical recommendations for the development of safer footwear. Ultimately, this study contributes to the existing knowledge base and supports efforts to prevent STFs in older adults through improved footwear design.

Changes in Foot Biomechanics during Pregnancy and Postpartum: Scoping Review

(1) Background: During pregnancy, changes in foot biomechanics affect structural stability and gait. (2) Objective: To map the available evidence for changes in foot biomechanics during pregnancy and the postpartum period. (3) Methods: Scoping review according to the methodology of the Joanna Briggs Institute through the relevant databases via EBSCO, MEDLINE with full text, BioOne Complete, CINAHL Plus with full text, Academic Search Complete, and SPORT Discus with full text. The search was conducted in SCOPUS and PubMed. (4) Results: Eight studies were included in the scoping review. Two independent reviewers performed data extraction and synthesized data in narrative form. We found that changes in the length and volume of the foot occur during pregnancy and remain in the postpartum period. (5) Conclusions: During pregnancy, anatomical and biomechanical changes occur in the pregnant woman's foot, potentially contributing to the risk of musculoskeletal disorders. However, more research is needed to determine whether these biomechanical changes can lead to the risk of musculoskeletal disorders.

Tai Chi counteracts age-related somatosensation and postural control declines among older adults

Objective

To investigate the effect of a 16-week Tai Chi practice on strength, tactile sensation, kinesthesia, and static postural control among older adults of different age groups.

Methods

This is a quasi-experimental study. Thirteen participants aged 60-69 years (60-69yr), 11 aged 70-79 years (70-79yr), and 13 aged 80-89 years (80-89yr) completed 16 weeks of 24-form Tai Chi practice. Their ankle and hip peak torque, tactile sensation, ankle and knee kinesthesia, and the root mean square of the center of pressure (Cop-RMS) were measured before (week 0) and after (week 17) practice.

Results

80-89yr showed less ankle plantar/dorsiflexion and hip abduction peak torques (p = 0.003, p < 0.001, p = 0.001), and a greater ankle plantar/dorsiflexion kinesthesia (p < 0.001, p = 0.002) than 60-69yr and 70-79yr. Greater ankle plantar/dorsiflexion and hip abduction torques (p = 0.011, p < 0.001, p = 0.045), improved arch and heel tactile sensation (p = 0.040, p = 0.009), and lower knee flexion/extension kinesthesia (p < 0.001, p = 0.044) were observed at week 17. The significant group*practice interaction for the fifth metatarsal head tactile sensation (p = 0.027), ankle plantar/dorsiflexion kinesthesia (p < 0.001, p = 0.004), and the CoP-RMS in the mediolateral direction (p = 0.047) only in 80-89yr revealed greater improvement at week 17.

Conclusion

Tai Chi practice increased strength, tactile sensation, kinesthesia, and static postural control among older adults. Tai Chi practice improved tactile, kinesthesia sensations, and static postural control among older adults over 80, who presented with worse strength and kinesthesia than their younger counterparts. Tai Chi practice offers a safe exercise option for those aged over 80 to encourage improvements in sensorimotor control.

Effects of Proprioceptive Insoles and Specific Core Training on Postural Stability for Preventing Injuries in Tennis

Tennis is a complex sport based on unpredictability that requires adequate physical and psychological preparation to prevent injuries. The aim of this study was to investigate the effects of 8-week specific core stability training on postural stability in competitive adolescent tennis players, aged between 14 and 19 years old. Sixty-one participants were randomly allocated into two groups: experimental (n = 32) and control (n = 29) groups. The first group wore proprioceptive insoles 8 h a day and performed a detailed training 3 times a week for 8 weeks; the second group only received proprioceptive insoles to wear 8 h a day for 8 weeks. The postural stability parameters (center-of-pressure length, center-of-pressure velocity, and 95% confidence ellipse sway area) included three assessment times: baseline (T0), intermediate test (T1), post-test (T2), and retention test (T3). Data analysis showed a significant improvement in the experimental group compared with the control group, indicating a large effect size in center-of-pressure length, ellipse sway area, and center-of-pressure velocity at T2 and T3 (p < 0.05). In conclusion, our results suggest that a specific and detailed core stability training plays a significant role in improving balance and postural stability in young tennis players, especially in terms of preventing the risk of injury.

Postural stability and plantar pressure parameters in healthy subjects: variability, correlation analysis and differences under open and closed eye conditions

Introduction: The "postural control system" acts through biomechanical strategies and functional neuromuscular adaptations to maintain body balance under static and dynamic conditions. Postural stability and body weight distribution can be affected by external sensory inputs, such as different visual stimuli. Little information is available about the influence of visual receptors on stabilometric and plantar pressure parameters. The aim of this study was to analyze variability, correlations, and changes in these parameters under open- (OE) and closed-eye (CE) conditions. Methods: A total of 31 stabilometric and plantar pressure parameters were acquired in 20 young and healthy adults during baropodometric examination performed in bipedal standing under both visual conditions. Variability of parameters was evaluated via the coefficient of variation, correlation analysis via Pearson's R2, and statistical differences via the Wilcoxon test. Results: High intra-subject repeatability was found for all plantar pressure parameters and CoP-speed (CV < 40%) under OE and CE conditions, while CoP-sway area (CoPsa) and length surface function (LSF) showed larger variability (CV > 50%). Mean and peak pressures at midfoot and total foot loads showed the least number of significant correlations with other parameters under both visual conditions, whereas the arch-index and rearfoot loads showed the largest number of significant correlations. The limb side significantly affected most plantar pressure parameters. A trend of larger LSF and lower CoPsa and mean and peak pressures at the right forefoot was found under the CE condition. Discussion: The present study provides a deeper insight into the associations between postural stability and foot load. Interesting postural adaptations, particularly with respect to different visual stimuli, the effect of the dominant side, and the specific role of the midfoot in balance control were highlighted.

Complexity of spatio-temporal plantar pressure patterns during everyday behaviours

The human foot sole is the primary interface with the external world during balance and walking, and also provides important tactile information on the state of contact. However, prior studies on plantar pressure have focused mostly on summary metrics such as overall force or centre of pressure under limited conditions. Here, we recorded spatio-temporal plantar pressure patterns with high spatial resolution while participants completed a wide range of daily activities, including balancing, locomotion and jumping tasks. Contact area differed across task categories, but was only moderately correlated with the overall force experienced by the foot sole. The centre of pressure was often located outside the contact area or in locations experiencing relatively low pressure, and therefore a result of disparate contact regions spread widely across the foot. Non-negative matrix factorization revealed low-dimensional spatial complexity that increased during interaction with unstable surfaces. Additionally, pressure patterns at the heel and metatarsals decomposed into separately located and robustly identifiable components, jointly capturing most variance in the signal. These results suggest optimal sensor placements to capture task-relevant spatial information and provide insight into how pressure varies spatially on the foot sole during a wide variety of natural behaviours.

Evaluation of functional parameters of the foot and ankle in elderly with sarcopenia

OBJECTIVE

With population aging, the prevalence of sarcopenia has increased. It is a pathology often neglected, with the potential to cause great damage if not diagnosed and treated. The objective of this study was to identify sarcopenic elderly people through the SARC-F score and palm grip test and to evaluate foot and ankle functionality parameters: gait speed, plantar sensitivity, and baropodometry.

METHODS

This is a descriptive and cross-sectional study. The sample consisted of 20 sarcopenic elderly diagnosed through the SARC-F score and the handgrip strength test, from which demographic data were obtained, and the three functional tests related to the foot and ankle were performed.

RESULTS

No individual was aware of the term sarcopenia. Regarding gait speed, 20 (100%) presented values compatible with sarcopenia (average of 0.52 m/s). Regarding plantar sensitivity, five (25%) of the patients showed changes in the exam with the detection of insensitivity. Regarding baropodometry, higher pressure values were observed in the right foot (average of 52.9±7.01%) compared to the left (average of 47.10±7.01%) and in the hindfoot (average of 55.85±16.21%) compared to the forefoot (mean 44.15±15.35%). When correlating the analyzed variables with the SARC-F scores, the only association that showed statistical significance (p<0.05) was the dynamometry on the right.

CONCLUSION

The SARC-F score and the handgrip strength test are easy to apply in the screening of sarcopenia, and the functional parameters of the foot and ankle were shown to be altered in the studied group.

Brain Connectivity Analysis in Distinct Footwear Conditions during Infinity Walk Using fNIRS

Gait and balance are an intricate interplay between the brain, nervous system, sensory organs, and musculoskeletal system. They are greatly influenced by the type of footwear, walking patterns, and surface. This exploratory study examines the effects of the Infinity Walk, pronation, and footwear conditions on brain effective connectivity patterns. A continuous-wave functional near-infrared spectroscopy device collected data from five healthy participants. A highly computationally efficient connectivity model based on the Grange causal relationship between the channels was applied to data to find the effective relationship between inter- and intra-hemispheric brain connectivity. Brain regions of interest (ROI) were less connected during the barefoot condition than during other complex walks. Conversely, the highest interconnectedness between ROI was observed while wearing flat insoles and medially wedged sandals, which is a relatively difficult type of footwear to walk in. No statistically significant (p-value <0.05) effect on connectivity patterns was observed during the corrected pronated posture. The regions designated as motoric, sensorimotor, and temporal became increasingly connected with difficult walking patterns and footwear conditions. The Infinity Walk causes effective bidirectional connections between ROI across all conditions and both hemispheres. Due to its repetitive pattern, the Infinity Walk is a good test method, particularly for neuro-rehabilitation and motoric learning experiments.

Short-term foot warming impacts foot sensitivity and body sway differently in older adults

BACKGROUND

Aging is accompanied by loss of foot skin sensitivity and reduced postural control. Increasing foot temperature can improve both skin sensitivity and postural control in adults. However, it remains unclear whether similar effects can be observed in older adults.

RESEARCH QUESTION

Can foot warming improve postural control in older adults, similar to observations in younger adults?

METHODS

Two foot warming protocols were conducted in 18 older adults (14 women, 4 men) to increase foot temperature by using infrared radiation to (1) warm the plantar aspect and (2) the skin of the entire foot and ankle area. We assessed the foot skin sensitivity before and after warming, considering tactile stimulation and center of pressure (CoP) displacement during 30-s standing with eyes open and closed.

RESULTS AND SIGNIFICANCE

Both foot warming protocols led to similar increases in skin temperature (∼6 °C) compared to the basal condition, but only warming the entire foot and ankle area increased foot sensitivity for the different regions assessed. No main effects or interactions were found for CoP variables in response to the two warming protocols. The short-term effects identified after warming the entire foot and ankle region suggest that this might be a strategy to improve skin sensitivity in older adults as observed in younger adults, but this was not the case for CoP. Future research should clarify whether the magnitude and long-lasting effects of warming could be determinant of CoP results.

The relationships of postural stability with muscle strength and proprioception are different among older adults over and under 75 years of age

Purpose

The relationships of postural stability with its three potential contributing factors, namely, muscle strength, tactile sensation, and proprioception, have not been clarified at different ages among older adults. Differences in the relationships may explain the increased incidence of falls among older adults 75 and older. This study compared the postural stability and its three factors between the older adults younger or older than 75 and investigated their age-specific relationships.

Methods

A total of 152 participants were recruited and divided into younger-old (65–74 years, n = 83) or older-old adults (≥75 years, n = 69) groups. Their Berg Balance Scale (BBS) and the Timed Up and Go (TUG) performance, muscle strength, tactile sensation, and proprioception were tested. The group differences and age-specific relationships of the performance with the three factors were examined.

Results

Compared to the younger-older adults, the older-old adults had lower BBS and higher TUG scores, weaker muscle strength, and worse proprioception. Muscle strength and proprioception were correlated with BBS and TUG among the younger-older adults. Only muscle strength but not proprioception among the older-old adults was correlated with BBS and TUG.

Conclusion

The older-old adults over 75 years have poorer postural stability, muscle strength, and proprioception compared to the younger-old adults aged 65–74 years. Proprioception provides information on postural stability among younger-old adults but not among older-old adults. Keeping proprioception from deteriorating with age could be a key to reducing falls in older-old adults.

Integration of reginal shear measurements at the foot-ground interface during routine balance assessment of the elderly population

BACKGROUND

Force-plate posturography offers a convenient way for quantitative assessment of postural stability in the elderly. However, studies focusing on routine balance assessment have usually not taken reginal shear distributions (i.e., arising from horizontal forces) into consideration.

RESEARCH QUESTION

(1) Does plantar shear distribution differ between young and elderly subjects during upright standing? (2) How do the maximum plantar shear forces vary at different regions of the foot?

METHODS

The new reginal shear measurement (RSM) method can simultaneously capture the three-dimensional force distributions at regional plantar sites while subjects maintaining standing balance. The feasibility of the proposed method in characterizing the magnitude and distribution of plantar shear forces was tested in thirty-two normal young and nineteen elderly subjects. Statistical analysis was performed using the independent samples t-test for both the continuous and ordinal variables.

RESULTS

For regional AP shear forces, statistically significant differences were found between the two groups for the toe region of the right foot and the midfoot of both feet. For ML shear distributions, statistically significant differences were found at nearly all plantar sites expect for the hallux and lateral metatarsal. The maximum increase in ML shear forces occurred in the toe region of the right foot, where the peak shear values were 113.16% higher than those of the young subjects. The peak ML shear occurred in the midfoot were averagely 83.19% and 70.57% higher in the elderly's left and right feet, respectively.

SIGNIFICANCE

The RSM method may offer unique solutions to identify functional decline in postural control of the elderly. The plantar shear pattern has potential to become an important parameter in evaluating one's balance performance during upright standing.

Effects of increasing temperature in different foot regions on foot sensitivity and postural control in young adults

Despite controversial evidence, foot sensitivity may influence postural control. Since skin temperature changes may induce changes in skin sensitivity, it remains unclear whether this also affects postural control. Here we examined the effects of increasing foot temperature on foot sensitivity and postural control responses. It is hypothesized that increases in foot temperature would improve foot sensitivity and enhance postural control. Furthermore, it was investigated whether warming a larger foot area provides additional benefits. Our hypothesis was tested by warming the foot plantar and the whole foot and ankle area (including foot plantar and instep) using infrared radiation and evaluated the center of pressure (CoP, bilateral, in two conditions: eyes open and eyes closed) and foot tactile sensitivity (Semmes-Weinstein Monofilaments) in 22 young participants. Both warming protocols significantly increased foot temperature by ∼5-6 °C and improved sensitivity, whereas more considerable improvements happened after warming the whole foot and ankle. CoP mediolateral oscillation and velocity with eyes open, and CoP area and velocity with eyes closed reduced after both warming protocols. Foot sensitivity seems to depend on the foot area warmed, whereas postural control improved equally regardless of the warmed regions. These results may support interventions based on the manipulation of foot temperatures to improve postural control with potential clinical applications in populations with impaired foot sensitivity and balance.

Plantar sensation, plantar pressure, and postural stability alterations and effects of visual status in older adults

PURPOSE

Ageing leads to plantar sensation and pressure alterations and poor postural control. The aim of this study was to compare the plantar sensation and static plantar pressure distribution between young and older adults. A secondary aim was to investigate the effect of ageing and visual status on postural stability.

MATERIALS AND METHODS

Forty older subjects and 43 young adult individuals participated in the study. Plantar light touch sensation was evaluated using Semmes-Weinstein monofilaments. Static plantar pressure and postural stability were assessed with the WinTrack^® Pedobarography device.

RESULTS

Plantar sensation thresholds of the older individuals were higher compared to the young in all plantar regions (p < 0.001). The plantar contact area was greater in older individuals (p < 0.001). Maximum plantar pressure of midfoot was higher and maximum plantar pressure of the rearfoot and whole foot was less in older individuals during quiet stance (p < 0.05). The main effects of group and visual condition were significant for mean latero-lateral and antero-posterior sway speed with large effect sizes (p < 0.05).

CONCLUSIONS

The sensation of all plantar regions reduced, the rearfoot plantar pressure decreased, and the midfoot plantar pressure increased in older individuals compared to young. Postural stability was reduced in the older individuals, and their postural control was more affected by the eliminated visual information compared to the young. Increased plantar contact area and midfoot plantar pressure may be related to decreased MLA height in older individuals. Older individuals may need visual information more to maintain postural control because of reduced plantar sensation.

The immediate effects of hallux valgus orthoses: A comparison of orthosis designs

BACKGROUND

Hallux valgus orthoses are available in a wide range of designs and materials, but the effects of their design on functional performance have not been fully investigated.

RESEARCH QUESTION

This present study aims to comprehensively analyze the immediate effects of soft and semi-rigid hallux valgus orthoses on balance, plantar pressure, hallux valgus angle, and subjective sensations.

METHODS

Sixteen female subjects have participated in the study, including 10 subjects with healthy feet and 6 with hallux valgus. Three conditions are tested, including in the barefoot and using two types of commercially available hallux valgus orthoses. The subjects participate in static and dynamic (walking) tests with the use of the Novel Pedar® system. The peak pressure values in the hallux, lateral toes, first metatarsophalangeal joint, 2-4th metatarsal heads, 5th metatarsal head, medial midfoot, lateral midfoot and rearfoot in the various foot conditions are examined and compared. The hallux valgus angle of each subject is measured based on their footprint. Their subjective feelings towards the orthoses are also evaluated. A repeated-measures analysis of variance, and independent-sample t-test are performed.

RESULTS

The correction of the hallux valgus angle is statistically significant when the subjects with hallux valgus use the orthoses. In comparing the two types of orthoses, the use of the orthosis made of soft materials results in correction in the hallux valgus angle and higher wear comfort, and lower plantar pressure in hallux area.

SIGNIFICANCE

The results provide insights into the design of hallux valgus orthoses, thus offering practical reference for the selection of hallux valgus orthosis with compromise between functional performance and wear comfort.

Are foot deformity and plantar sensitivity impairment associated with physical function of community-dwelling older adults?

BACKGROUND

Foot deformities are highly prevalent in older adults and negatively impact their mobility and quality of life. However, the association between foot problems and physical function is still unclear.

OBJECTIVE

To investigate whether structural foot deformities and plantar tactile sensitivity are associated with lower extremity physical function impairment in community-dwelling older adults.

METHODS

We included 200 men and women aged 60 years and older from a community-based program. The foot assessment included toe deformities and calluses inspection and evaluation of plantar tactile sensitivity using monofilaments. The Short Physical Performance Battery (SPPB) was used to assess lower extremity physical function. We conducted a multivariate logistic regression analysis to investigate the association between foot problems and lower extremity physical function.

RESULTS

Hallux valgus was the most prevalent deformity among older adults. Those participants with reduced plantar tactile sensitivity (OR= 2.77; 95% CI: 1.38, 5.55) and a hallux valgus (OR= 2.23; 95% CI: 1.10, 4.52) were more likely to present poor lower extremity physical function.

CONCLUSION

Hallux valgus and impaired plantar sensitivity were associated with reduced lower extremity physical function in older adults. Further studies are necessary to identify this causality and to what extent management of these foot problems can improve general mobility and quality of life of older adults.

Immediate effect of insoles on balance in older adults

BACKGROUND

In recent years, fall prevention in older adults has received considerable attention in healthcare. Among many interventions, insoles are considered cost-effective and easily adopted tools to improve balance in older people. Numerous studies have verified the immediate effects of insoles on balance in older adults. However, there is still lack of consensus regarding the immediate benefits of using insoles on balance improvement.

RESEARCH QUESTION

Given this, a meta-analysis was conducted to provide more conclusive evidence about the immediate effect of insoles on balance in older adults and answer the question: "Do insoles influence balance in older people?"

METHODS

PubMed, NDSL, Medline, Google Scholar, and Web of Science were searched from March to August 2018. The key terms were "insole", "elderly", "gait", "balance", "shoe", "foot", and "postural". Finally, seven primary studies were selected for this meta-analysis. The balance related outcomes were coded to compute effect sizes and the overall effect size of the standardized mean differences was analyzed. Moderating variables included kinematic variables of balance, static and dynamic balance, and type of insole.

RESULTS

The overall effect size of insoles was medium (d = 0.618), which suggests that insoles are beneficial for older adults for improving balance. More specifically, this study revealed that textured and vibration insoles were the most effective types of insoles.

SIGNIFICANCE

This finding supports the idea that augmented tactile and mechanical sensory input from insoles can enhance the postural control mechanisms in older adults with age-related deterioration of sensory mechanisms. The use of insoles may lead to a reduction in the rate of falls which are related to decreased quality of life in older adults.

Influence of age, gender and obesity on pressure discomfort threshold of the foot: A cross-sectional study

BACKGROUND

Foot pain is a highly prevalent health problem for which measures such as a pattern of Pressure Discomfort Threshold of the foot plantar surface can provide valuable information for orthosis design. This study aimed to describe such pattern as a tool for the assessment of painful conditions of the feet and to analyse how it modifies according to age, gender and obesity.

METHODS

A cross-sectional study was performed with participants allocated in: Group 1 people aged 20 to 35 years, Group 2 aged 50 to 65 years and Group 3 aged over 65. Pressure Discomfort Threshold on twelve points of the foot plantar surface was measured with an adapted manual dynamometer. Inferential analyses of the data were performed using one-way analysis of variance (ANOVA) considering foot areas, age group, gender and obesity.

FINDINGS

36 participants were analysed. The pattern of Pressure Discomfort Threshold for all individuals showed a significantly higher threshold on the heel and external foot (P < 0.001, η² = 0.124) and was statistical significantly influenced by age (P < 0.001, η² = 0.17), especially in participants aged over 65; by gender, with women having higher values (P < 0.001, η² = 0.13), and by obesity (P < 0.001, η² = 0.19).

INTERPRETATION

A Pressure Discomfort Threshold pattern exists in the foot plantar surface. The characteristics of the discomfort pattern of the foot and its association with aging, gender and obesity may have considerable implications for orthosis and footwear design.

Cutaneous and muscular afferents from the foot and sensory fusion processing: Physiology and pathology in neuropathies

The foot-sole cutaneous receptors (section 2), their function in stance control (sway minimisation, exploratory role) (2.1), and the modulation of their effects by gait pattern and intended behaviour (2.2) are reviewed. Experimental manipulations (anaesthesia, temperature) (2.3 and 2.4) have shown that information from foot sole has widespread influence on balance. Foot-sole stimulation (2.5) appears to be a promising approach for rehabilitation. Proprioceptive information (3) has a pre-eminent role in balance and gait. Reflex responses to balance perturbations are produced by both leg and foot muscle stretch (3.1) and show complex interactions with skin input at both spinal and supra-spinal levels (3.2), where sensory feedback is modulated by posture, locomotion and vision. Other muscles, notably of neck and trunk, contribute to kinaesthesia and sense of orientation in space (3.3). The effects of age-related decline of afferent input are variable under different foot-contact and visual conditions (3.4). Muscle force diminishes with age and sarcopenia, affecting intrinsic foot muscles relaying relevant feedback (3.5). In neuropathy (4), reduction in cutaneous sensation accompanies the diminished density of viable receptors (4.1). Loss of foot-sole input goes along with large-fibre dysfunction in intrinsic foot muscles. Diabetic patients have an elevated risk of falling, and vision and vestibular compensation strategies may be inadequate (4.2). From Charcot-Marie-Tooth 1A disease (4.3) we have become aware of the role of spindle group II fibres and of the anatomical feet conditions in balance control. Lastly (5) we touch on the effects of nerve stimulation onto cortical and spinal excitability, which may participate in plasticity processes, and on exercise interventions to reduce the impact of neuropathy.

Effect of visual condition and physical activity on the plantar pressure distribution in adult and older women

Abstract The aging process causes changes in the physical and functional conditions, as well as in the foot structure and function. This study aimed to analyze the plantar pressure variation with respect to visual information and physical activity in adult and older women. This was a cross-sectional study that included 142 women (mean age of 67.8 years). Participants responded the anamnesis questionnaire, Mini Mental State Examination, and International Physical Activity Questionnaire. Plantar pressure was assessed using computerized baropodometry. Weight distribution was observed in semitandem positions for the right foot forward and then the left foot forward . Data analysis showed that foot type had no correlation with age (p = 0.37 right foot; p = 0.93 left foot) or level of physical activity (p = 0.28 right foot; p = 0.96 left foot). Moreover, plantar pressure variation showed no significant relationship with age (R2 = 0.2; p = 0.6). In conclusion, plantar pressure variation is not associated with the morphological foot type in women analyzed, as the visual condition did not generate plantar pressure variations when compared to its effect on the classification of plantar arches. Furthermore, level of physical activity was not associated with plantar pressure variation .

Immersive Virtual Tasks With Motor and Cognitive Components: A Feasibility Study With Young and Older Adults

OBJECTIVE

To analyze the feasibility, safety, and acceptability of immersive virtual tasks.

METHODS

The authors recruited 11 young adults and 10 older adults. The participants performed three virtual reaching tasks while walking on a virtual path. The descriptive analysis and comparison between participants were performed using the Mann-Whitney U test and chi-square test for nonparametric and nominal variables, respectively. The authors also used analysis of variance for a between-groups comparison for normal variables.

RESULTS

Twenty percent of older adults and 81.8% of young adults completed all three tasks (chi-square test; p = .005). Both groups reported minor symptoms, with no significant differences. The older adults were more motivated to practice the tasks (Mann-Whitney U test; p = .015) and would be more likely to suggest them to others (chi-square test; p = .034).

CONCLUSION

All three tasks were feasible for young adults. All participants, except for one, had cybersickness. The symptoms were mostly mild and subsided once the interaction was complete.

The influence of age and overweight or obesity on foot sensitivity and postural control: A systematic review

OBJECTIVE

To perform a systematic review on the influence of age and overweight-or obesity-on foot sensitivity, as well as its relationship with balance and postural control.

METHODS

Publications in the following databases were searched up to December 2018: Cochrane Library, PubMed, Scopus, SPORTDiscus and Web of Science. Both randomised controlled and non-randomised trials, plus cross-sectional studies that evaluated foot sensitivity and balance in adults and/or older people, were investigated.

RESULTS

A total of 152 studies were found, 14 studies were included and 506 people of both sexes were involved in the included studies.

CONCLUSIONS

Increased age represented a detrimental effect on foot sensitivity. Most studies showed that decreased foot sensitivity was related to worse balance and/or postural stability. Overweight or obesity was associated with plantar sensitivity, with lower sensitivity and decreased postural stability observed in obese people.

Parâmetros da pressão plantar, tipo e sensibilidade do pé em recrutas: um estudo prospectivo

RESUMO Este estudo teve como objetivo avaliar as características da pressão plantar, tipo e sensibilidade do pé em recrutas durante o período do serviço militar obrigatório. Sessenta indivíduos que prestaram o serviço militar obrigatório foram avaliados para pressão plantar (baropodômetro EPS LoranEngineering, Bolonha, Itália) e sensibilidade plantar ao toque superficial (estesiômetro de Semmes-Weinsten) em três momentos distintos: março (linha de base), junho (após 16 semanas de treinamento) e setembro (após 36 semanas de treinamento militar). Foram avaliadas a descarga de peso ântero-posterior e latero-lateral, pressão média, pressão máxima, área de contato do pé, tipologia de pé e sensibilidade plantar. Os dados foram analisados pelo teste do Qui-quadrado, anova de medidas repetidas e pelo teste de Friedman com pos hoc de Bonferroni (p<0,05). Houve aumento na área de contato (p=0,001) e na pressão média de ambos os pés (p<0,001). Quanto a tipologia, aproximadamente 60% dos indivíduos possuíam o pé direito do tipo normal, enquanto o pé esquerdo era do tipo cavo (50,3%); ou seja, mesmos sujeitos apresentaram diferentes tipologias do pé. Em relação a sensibilidade plantar, houve diferença na região do médio pé ao longo do treinamento (p=0,001 no pé dominante e p=0,009 no pé não dominante). Esses resultados demonstram que houve aumento da pressão média e área total de contato do pé, bem como alterações na sensibilidade plantar da região do médio pé ao longo do serviço militar obrigatório.

Differentiating Sitting, Standing, and Walking Through Regional Plantar Pressure Characteristics

Prolonged static weight bearing (WBR) is thought to aggravate plantar heel pain and is common in the workplace, which may put employees at greater risk of developing plantar heel pain. However, objective measures of physical activity and sedentary behaviors in the workplace are lacking, making it difficult to establish or refute the connection between work exposure and plantar heel pain. Characterizing loading patterns during common workplace postures will enhance the understanding of foot function and inform the development of new measurement tools. Plantar pressure data during periods of sitting, standing, and walking were measured in ten healthy participants using the F-Scan in-shoe measurement system (Tekscan Inc, Boston, MA). Peak and average pressure, peak and average contact area, and average pressure differential were analyzed in ten different regions of the foot. A two-way repeated measures analysis of variance (ANOVA) assessed the posture by foot region interaction for each measurement parameter; significant effects of posture by foot region were identified for all five measurement parameters. Ten foot region by measurement parameter combinations were found to significantly differentiate all three postures simultaneously; seven used pressure measures to differentiate while three used area measures. The heel, lateral midfoot (LM), and medial and central forefoot (CFF) encompassed nine of ten areas capable of differentiating all postures simultaneously. This work demonstrates that plantar pressure is a viable means to characterize and differentiate three common workplace postures. The results of this study can inform the development of measurement tools for quantifying posture duration at work.

Effect of Tai Chi Training on Plantar Loads during Walking in Individuals with Knee Osteoarthritis

Tai Chi is an available method for the treatment of knee osteoarthritis (KOA). The impacts of Tai Chi on plantar loads of individuals with KOA are not fully understood. 46 participants with knee osteoarthritis were randomly assigned into the Tai Chi group (n = 23) or the control group (n = 23). The Tai Chi group attended a 6-month Tai Chi program, and the control group participated in a wellness education program. Novel Pedar-X system was used to collect the peak pressure (PP) and maximum force (MF) during walking before and 6 months after the intervention. Significant higher peak pressure and maximum force were observed in the 4th and 5th metatarsophalangeal joints in the Tai Chi group. However, there were significant declines in the peak pressure of the whole foot and the 2nd and 3rd metatarsophalangeal joints and maximum force of the heel in the control group. These results suggested that individuals with KOA might change the pattern of plantar loads during walking through Tai Chi, and plantar loads would be useful as a parameter to assess the effect of Tai Chi on knee osteoarthritis. This trial is registered with Clinical Trials: CHiCTR-TRC-13003264.

Influence of Textured Indoor Footwear on Posture Stability of Older Women Based on Center-of-Pressure Measurements

OBJECTIVE

The objective of this study is to evaluate the efficacy of indoor footwear with a textured surface to improve control of balance and reduce excessive plantar pressure in older women.

BACKGROUND

Balance instability is a common condition in older people. Textured insoles with protrusions on the entire insole have been examined for enhancing somatosensory feedback in the elderly to improve control over balance. However, these insoles have significant challenges in distributing the plantar pressure. Textured insoles with tailored protrusions should be therefore investigated for the same purpose but provide better plantar pressure distribution.

METHOD

A total of 24 older women have undergone both static standing and walking tests with the use of the in-shoe Pedar® system.

RESULTS

The results indicate that wearing textured indoor footwear provides a significant reduction in postural sway, particularly in the medial-lateral direction during walking. As compared to walking barefoot, the center-of-pressure trajectory when wearing the textured indoor footwear remains supported with less variance among the steps, which is statistically significant in the medial-lateral direction. A significant reduction in the peak pressure is found in the forefoot and rearfoot regions as the plantar pressure is redistributed to the midfoot regions.

CONCLUSION

The textured surface of the insole improves balance control of older women and effectively reduces foot pressure at high pressure areas.

APPLICATION

The findings enhance current understanding on textured footwear as a form of intervention associated with changes in functional impairments, therefore providing basis for footwear design in balance control.

Comfortably numb? Experiences of people with stroke and lower limb sensation deficits: impact and solutions

PURPOSE

To explore personal experiences of loss of foot sensation following stroke in order to inform the focus of clinical assessments and development of a vibrotactile insole.

METHODS

Qualitative design with an interpretive phenomenological approach to data collection and analysis. Eight community dwelling adults with stroke (>6 months) and sensory impairment in the feet participated. Data was collected via conversational style interviews which were transcribed and analyzed using a thematic framework. Themes were verified with co-researchers and a lay advisory group.

RESULTS

Data formed four themes: Sensory deficits are prevalent and constant, but individual and variable; Sensory deficits have a direct impact on balance, gait, mobility and falls; Sensory deficits have consequences for peoples' lives; Footwear is the link between function, the environment and identity. They embraced the concept of discrete vibrotactile insoles, their potential benefits and demonstrated a willingness to try it.

CONCLUSIONS

Sensory deficit contributes to effects upon physical function, mobility and activity. Clinical outcome measures need to capture the emotional, psychological and social impacts of sensory deficit. Participants demonstrated a resilience and resourcefulness through adaption in daily living and self-management of footwear. The participants focus on footwear provides the opportunity to develop discrete and non-burdensome vibrotactile insoles for this patient group.IMPLICATIONS FOR REHABILITATIONSensory deficits are wide ranging and varied and are not distinct from motor deficits though contribute to the overall effect on physical function, mobility and activity.The physical effects impact on participants' lives emotionally, psychologically and socially. Measurement of outcomes need to capture specific activities that are valued by patients.The participants have revealed resilience and resourcefulness to create a "new normal" for their lives through adaption and self-management with a focus being on footwear as a solution.The participants have revealed the need for insole interventions to be discreet and non-burdensome, welcoming insole technology and contributing to the design and features of such insoles.

Sensitivity of the foot in the flat and toe off positions

The purpose of this study is to examine the differences in pressure sensitivity for areas of the foot in a toe-off position and with the feet on the ground. This data could provide a base for adapting the softness of different areas while designing footwear. 21 healthy subjects are asked to participate in a test where a researcher applies pressure with an advanced force gauge in 20 locations on the foot until the subject starts experiencing discomfort. Rigid shells of three sizes have been designed and 3D printed based on 3D foot scans. The test is performed in two positions: standing with load on the plantar surface and toe-off loading only the forefoot. The outcome is a pressure discomfort threshold map of the foot. Interestingly, in 16 locations the sensitivity was similar in both conditions (toe-off and complete foot on the ground). Especially, stretched areas showed increased sensitivity.

Proprioceptive activities to postural balance of the elderly - systematic review

Abstract Introduction: Proprioceptive activities are commonly described for control of the postural balance of the elderly in order to avoid falls. But, there is no consensus on which ones can significantly improve balance or on intervention and assessment protocols. Objective: To investigate which proprioceptive activities are specific to static and dynamic postural balance of the elderly through a systematic review. Method: This is a systematic review based on PRISMA recommendation, by surveying PubMed, Medline, LILACS, Scielo and EBSCO databases. The period considered for the search was from 2006 to 2016, using the following descriptors - aged, proprioception, exercise therapy, and postural balance for articles in English, Portuguese or Spanish. Randomized and non-randomized clinical trials were included using the PEDro scale to analyze the methodological quality of the studies. Results: Eight articles were included with different protocols, without standardization of evaluation and intervention, but, which demonstrated improvement of functional abilities. Different kinds of walk, muscular strengthening exercises, stretching, postural oscillations and Yoga patterns for the improvement of functional abilities. Conclusion: The association of static and dynamic activities can contribute to the improvement of functional abilities, but it cannot be affirmed that they are specific for postural control, given the lack of standardization of exercise protocols and evaluation tools.

Within and between-days repeatability and variability of plantar pressure measurement during walking in children, adults and older adults

BACKGROUND

Previous studies discussed the repeatability and variability in plantar pressure measurement, but a few considered different age groups. Here we determine within and between-days repeatability and variability of plantar pressure measurement during gait in participants from different age groups.

METHOD

Plantar pressure was recorded in children, young adults and older adults walking at preferred speed in four non-consecutive days within one week. Data from 10 steps from each foot in each day were analyzed considering the different regions of the foot. Mean and peak plantar pressure and data variability were compared between the steps, foot regions and days.

RESULTS

To describe mean and peak pressure during gait in children and adults a single measurement can be enough, but elderly will requires more attention especially concerning peak values. Variability in mean pressure did not differ between age groups, but peak pressure variability differed across foot regions and age groups.

CONCLUSION

One single observation can be used to describe plantar pressure during gait in children and adults. When the interest concerns older people, it might be pertinent to consider more than one day of assessment, especially when looking at peak pressure.

The effects of plantar perception training on balance and falls efficacy of the elderly with a history of falls: A single-blind, randomized controlled trial

PURPOSE

The purpose of this study was to identify the effects of plantar perception training using a hardness discrimination task on balance and falls efficacy of the elderly who have experienced a fall.

MATERIALS AND METHODS

Sixty-two elderly persons 65 years of age or older were randomly allocated to the experimental group (n = 31) or the control group (n = 31). The experimental group performed a hardness discrimination task using five different levels of hardness of sponge mats, while the control group performed the same task except that they were not asked to discriminate hardness levels of sponge mats. All subjects performed 10 sessions for two weeks. Outcome measures were conducted using center of pressure (CoP) sway in the standing position, the Timed Up and Go (TUG) test, and falls efficacy scale (FES) to measure balance and falls efficacy.

RESULTS

There were no significant differences in general characteristics between both groups (p > .05). After 10 sessions, plantar perception was significantly improved in the experimental group (F = 101.18, p < .001). Additionally, changes in CoP sway with eye closed and TUG test were significantly different (p < .05) between the experimental group (CoP sway with eye closed, -208.32 ± 74.89; TUG test, -1.91 ± 0.72) and the control group (CoP sway with eye closed, -14.55 ± 35.44; TUG test, -1.31 ± 0.75).

CONCLUSIONS

These results showed that plantar perception training might be beneficial to improve falls efficacy as well as balance of the elderly.

Changes in the pressure distribution by wrist angle and hand position in a wrist splint

The study was conducted to provide basic data to develop a system that distributes pressure over a broader area by measuring and analyzing pressures in various wrist angles and hand positions while wearing a wrist splint. With 0, 15, 30, and 45 degrees of wrist extension, full-finger extension and finger flexion, pressure distribution changes were measured three times. Average peak pressure was analyzed and mean value picture (MVP) in zones 3-5 was calculated. A one-way Anova was conducted to identify changes in pressure distribution by wrist angle and hand position. Mean peak pressure values (kPa) in zones 3-5 changed depending on the wrist angle. Peak pressures (kPa) changed significantly in 15, 30, and 45 degrees wrist extension, depending on the hand position. Since pressure distributions differ depending the wrist angle and hand position (finger flexion), it is necessary to consider how pressure varies in each wrist position and to provide information on postures that should be avoided during tasks and occupational activities based on various wrist angles or hand positions.

A wearable vibrotactile biofeedback system improves balance control of healthy young adults following perturbations from quiet stance

Maintaining postural equilibrium requires fast reactions and constant adjustments of the center of mass (CoM) position to prevent falls, especially when there is a sudden perturbation of the support surface. During this study, a newly developed wearable feedback system provided immediate vibrotactile clues to users based on plantar force measurement, in an attempt to reduce reaction time and CoM displacement in response to a perturbation of the floor. Ten healthy young adults participated in this study. They stood on a support surface, which suddenly moved in one of four horizontal directions (forward, backward, left and right), with the biofeedback system turned on or off. The testing sequence of the four perturbation directions and the two system conditions (turned on or off) was randomized. The resulting reaction time and CoM displacement were analysed. Results showed that the vibrotactile feedback system significantly improved balance control during translational perturbations. The positive results of this preliminary study highlight the potential of a plantar force measurement based biofeedback system in improving balance under perturbations of the support surface. Future system optimizations could facilitate its application in fall prevention in real life conditions, such as standing in buses or trains that suddenly decelerate or accelerate.

Ankle muscle co-contractions during quiet standing are associated with decreased postural steadiness in the elderly

It has been reported that the elderly use co-contraction of the tibialis anterior (TA) and plantarflexor muscles for longer duration during quiet standing than the young. However, the particular role of ankle muscle co-contractions in the elderly during quiet standing remains unclear. Therefore, the objective of this study was to investigate the association between ankle muscle co-contractions and postural steadiness during standing in the elderly. Twenty-seven young (27.2±4.5yrs) and twenty-three elderly (66.2±5.0yrs) subjects were asked to stand quietly on a force plate for five trials. The center of pressure (COP) trajectory and its velocity (COPv) as well as the center of mass (COM) trajectory and its velocity (COMv) and acceleration (ACC) were calculated using the force plate outputs. Electromyograms were obtained from the right TA, soleus (SOL), and medial gastrocnemius (MG) muscles. Periods of TA activity (TAon) and inactivity (TAoff) were determined using an EMG threshold based on TA resting level. Our results indicate that, in the elderly, the COPv, COMv, and ACC variability were significantly larger during TAon periods compared to TAoff periods. However, in the young, no significant association between respective variability and TA activity was found. We conclude that ankle muscle co-contractions in the elderly are not associated with an increase, but a decrease in postural steadiness. Future studies are needed to clarify the causal relationship between (1) ankle muscle co-contractions and (2) joint stiffness and multi-segmental actions during standing as well as their changes with aging.