When does mechanical plantar stimulation promote sensory re-weighing: standing on a firm or compliant surface?

Impact of five floor coverings on the orthostatic balance of healthy subjects

Plantar skin sensitivity contributes to the regulation of postural control and, therefore, changing the characteristics of the plantar support surface can modify this control. This study aimed at assessing the impact of five different floor coverings on the orthostatic balance in 48 healthy subjects. Static posturography was performed with eyes open or closed on a platform in a control condition (no covering) and with five different covering surfaces: foam, silicone, ethyl vinyl acetate, and two textured mats with small (height 2 mm) or large pimples (7 mm). The average velocity of center of pressure (CoP) displacement was the primary endpoint measure and ten other posturographic variables were assessed. Comfort and pain produced by the covering were also scored. In eyes open condition, the average velocity of CoP displacement was increased when subjects stood on the foam mat, the silicone mat, and especially the textured mat with large pimples. Several other posturographic variables showed significant changes with different types of floor coverings with eyes open. These changes were not correlated to the comfort or pain scores associated with the different surfaces. In contrast, no difference was observed compared to the control condition (no covering) with eyes closed. This study shows that adding smooth or textured floor covering can alter balance in eyes open condition. In eyes closed condition, although more disturbing for balance, healthy subjects achieved better postural adaptation, probably by mobilizing more of their proprioceptive resources. This posturographic examination procedure could, therefore, be used to assess "proprioceptive reserve" capacities in clinical practice.

Short-Term Effects of Manual Therapy on Balance: A Multicenter, Randomized, Double-Blind Controlled Trial

OBJECTIVE

The purpose of this study was to analyze short-term changes in dynamic and static balance after a manual therapy protocol in healthy participants and analyze any repercussions on mood and perception of change after applying articulatory techniques.

METHODS

A single-blind, randomized, multicenter clinical trial was conducted. Participants were allocated to either a manual therapy group (MTG) (n = 101) or a control group (CG) without intervention (n = 99), and measures were taken before treatment, after the intervention, and 1 week after treatment. Assessments included the Star Excursion Balance Test, Unipedal Stance Test (UPST), Profile of Mood States (POMS), and Patient Global Impression of Change (PGIC) scale.

RESULTS

Two hundred healthy participants completed the study (mean age, 22 [SD = 2.67]). There was a statistically significant interaction between groups and time measurements in the right leg for anterior (P = .003), posteromedial (P < .001), and posterolateral (P = .001) directions in favor of the MTG, as well as in the left leg for anterior (P < .001), posteromedial (P < .001), and posterolateral (P = .012) directions. The analysis failed to show statistically significant interactions between any of the factors for the UPST and POMS (P > .05). The MTG showed a significant improvement compared to the CG after treatment (P = .003) and at 1-week follow-up (P < .001) on the PGIC scale.

CONCLUSION

The results suggest the MT intervention was effective on dynamic balance in post-intervention in healthy participants, and some of the directions maintained the results at 1-week follow-up. Perception of change in post-treatment and 1-week follow-up also significantly improved. The protocol did not seem to produce changes in static balance and mood states. Positive changes after manual therapy were maintained in the short term.

Immediate effect of textured insoles on the balance in patients with diabetic neuropathy

AIMS/INTRODUCTION

Neuropathy is a common complication of diabetes that reduces balance by disrupting vision, and the sensory and vestibular systems. This is important in older adults who are more at risk of falling. Studies show that improving the sensory mechanisms through insoles can improve balance in people with balance disorders. As textured insoles have recently been considered for improving balance disorders, this study aimed to investigate the immediate effect of textured insoles on the balance of patients with diabetic neuropathy.

MATERIALS AND METHODS

A total of 17 patients with diabetic neuropathy participated in this quasi-experimental study. The studied variables were the general balance index, posterior-anterior balance index and medial-lateral balance index, which were measured in three conditions: (i) soft textured insoles; (ii) hard textured insoles; and (iii) without textured insoles. A Biodex balance device was used for this purpose.

RESULTS

In the general balance index, there was a significant difference between all the studied conditions. In the posterior-anterior balance index, there was a significant difference between without textured insole and hard textured insoles, and also soft and hard textured insoles. In the medial-lateral balance index, there was a significant difference between the hard textured insoles and without textured insoles, and also soft and hard textured insoles (P < 0.05).

CONCLUSIONS

Wearing textured insoles can increase the balance in patients with diabetic neuropathy. This can be due to its effect on the sensory feedback of the soles, improving the proprioception and tactile sensors that are the main sources of balance.

Vertical ground reaction force oscillation during standing on hard and compliant surfaces: The “postural rhythm”

When a person stands upright quietly, the position of the Centre of Mass (CoM), the vertical force acting on the ground and the geometrical configuration of body segments is accurately controlled around to the direction of gravity by multiple feedback mechanisms and by integrative brain centres that coordinate multi-joint movements. This is not always easy and the postural muscles continuously produce appropriate torques, recorded as ground reaction force by a force platform. We studied 23 young adults during a 90 s period, standing at ease on a hard (Solid) and on a compliant support (Foam) with eyes open (EO) and with eyes closed (EC), focusing on the vertical component of the ground reaction force (VGRF). Analysis of VGRF time series gave the amplitude of their rhythmic oscillations (the root mean square, RMS) and of their frequency spectrum. Sway Area and Path Length of the Centre of Pressure (CoP) were also calculated. VGRF RMS (as well as CoP sway measures) increased in the order EO Solid ≈ EC Solid < EO Foam < EC Foam. The VGRF frequency spectra featured prevailing frequencies around 4–5 Hz under all tested conditions, slightly higher on Solid than Foam support. Around that value, the VGRF frequencies varied in a larger range on hard than on compliant support. Sway Area and Path Length were inversely related to the prevailing VGRF frequency. Vision compared to no-vision decreased Sway Area and Path Length and VGRF RMS on Foam support. However, no significant effect of vision was found on VGRF mean frequency for either base of support condition. A description of the VGRF, at the interface between balance control mechanisms and sway of the CoP, can contribute information on how upright balance is maintained. Analysis of the frequency pattern of VGRF oscillations and its role in the maintenance of upright stance should complement the traditional measures of CoP excursions in the horizontal plane.

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.

Contribution of Somatosensory and Parietal Association Areas in Improving Standing Postural Stability Through Standing Plantar Perception Training in Community-Dwelling Older Adults

Although standing plantar perception training (SPPT) may improve standing postural stability, the underlying neural mechanisms remain unclear. The authors investigated the relationship between regional cortical responses to SPPT using a balance pad and training outcomes in 32 older participants (mean ± SD:72.2 ± 6.0, range:60-87). Regional cortical activity was measured in the bilateral supplementary motor area, primary sensorimotor area, and parietal association area using near-infrared spectroscopy. Postural sway changes were compared before and after SPPT. Changes in two-point plantar discrimination and regional cortical activity during SPPT, associated with standing postural stability improvements, were examined using multiple regression and indicated improved standing postural stability after SPPT (p < .0001). Changes in right parietal association area activity were associated with standing postural stability improvements while barefoot. Overall, the results suggest that right parietal association area activation during SPPT plays a crucial role in regulating standing postural stability and may help develop strategies to prevent older adults from falling.

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.

Balance in focus: a simple observational scale to monitor the effect of exercises on static balance in case of childhood flexible flat foot

[Purpose] Childhood flexible flat foot is the most common lower limb deformity. Observational evaluation of the underlying elements of reactive balance during static positions is an accepted tool besides the timed measures. We aim to assess the effects of combined balance training on the foot function and to test the usefulness of our observational static balance score. [Participants and Methods] A total of 19 healthy primary school students with flexible flat foot deformity volunteered for the study. We evaluated the foot’s dynamic properties and static postural stability before and after a 20-week combined balance training. On the basis of the observational findings, the time vs. quality observational static balance score was developed. All data were subjected to Wilcoxon’s test and Friedman’s ANOVA to compare the effects of the training on foot trajectory and observational static balance score. [Results] Better strength and endurance in the foot extensors and improved foot function were noted after the training. Using our observational static balance score, the quality of the balance performance remarkably changed. [Conclusion] The quality domain of our new scale seems to be a useful tool in daily clinical practice and a more sensitive measure in eyes-closed situations.

The immediate effect of plantar stimulation on dynamic and static balance: A randomized controlled trial

OBJECTIVE

To examine the immediate effect on dynamic and static balance of a manual protocol of plantar stimulation in healthy subjects.

MATERIALS AND METHOD

Of the 144 healthy and physically active volunteers recruited, 98 subjects participated. Subjects were randomly assigned and allocated to the experimental group (EG) (n= 50), in which a 10-min manual protocol of plantar stimulation was applied on the right foot, or to the control group (CG) (n= 48). The change scores of the modified Star Excursion Balance Test (mSEBT) and the Unipedal Stance Test (UPST) were used to assess the immediate effect of the protocol on dynamic and static balance, respectively.

RESULTS

In the dynamic balance, a group effect was found in the anterior direction, posteromedial direction and composite scores of the mSEBT when groups were compared by limb. Changes in the posteromedial direction of both limbs (right limb: p= 0.002, left limb: p= 0.05) and composite score of the right limb (p= 0.009) were significantly greater in the EG versus the CG. Non-significant results were found in the static balance (UPST time).

CONCLUSIONS

The application of a 10-minute manual stimulation protocol without joint mobilization, addressed to stimulate the plantar cutaneous mechanoreceptors, could elicit benefits on dynamic balance. This improvement was observed bilaterally even though only one plantar surface was stimulated. As balance deficits may impair functional movements and regular training in sports, this intervention aims to ameliorate dynamic balancing ability could improve the functional recovery of sport gestures.

The Effects of Textured Insoles on Cortical Activity and Quiet Bipedal Standing With and Without Vision: An EEG Study

Wearing textured insoles (TIs) can reduce static postural sway, but the neurophysiological mechanisms by which these changes occur are not well understood. To address this issue, cortical activity was investigated in this study using electroencephalography (EEG) recordings from 19 scalp locations, in 15 healthy young adults (5 females; mean age = 27 ± 4.09 years) during quiet bipedal standing, under different insole conditions (textured versus smooth), with and without vision. Compared to smooth insoles (SIs), TIs significantly reduced postural sway in two measures; anterior-posterior range and standard deviation. In the EEG data, whole-head analyses showed cortical activity in the upper alpha power band was significantly reduced for textured compared to SIs. Exploratory analyses revealed this effect was significant both with and without vision, and was more pronounced over the parietal, compared to central regions, and over central compared to frontal regions. This trend was observed in low alpha and theta bands, but the effect of insole type was not significant. Textured insoles thus appear to affect not only balance outcomes but also cortical activity. The cortical activity adaptation may represent greater information becoming readily available at the cortical level, enhancing the representation of the body in space.

The effects of textured materials on static balance in healthy young and older adults: A systematic review with meta-analysis

BACKGROUND

Standing on textured materials can improve static balance, potentially by modulating somatosensory inputs from the soles of the feet.

RESEARCH QUESTION

To synthesise and quantify the immediate effects of textured materials on static balance in healthy young and older adults.

METHODS

Primary outcomes were the centre of pressure (COP) displacement and velocity, during eyes open and eyes closed conditions. Ten crossover studies (n = 318, 58% female) met the inclusion criteria. A random effects meta-analysis model derived pooled standardised mean differences (SMD; Hedges g) to quantify the effects of textured materials. Heterogeneity was quantified with the tau-statistic (τ). A 95% prediction interval quantified the likely range of true effects on COP outcomes in similar future studies.

RESULTS

There was a small to moderate beneficial effect for textured materials vs control conditions in: COP displacement during both eyes open (SMD: 0.29; 95% CI -0.06 to 0.64; τ = 0.32) and eyes closed (SMD: 0.75; 95% CI 0.18 to 1.33; τ = 0.55). A trivial to small beneficial effect was observed in COP velocity during eyes open (SMD: 0.14; 95% CI -0.14 to 0.43; τ = 0.18) and eyes closed (SMD: 0.20; 95% CI 0.01 to 0.40; τ = 0.18) for textured materials. The 95% prediction intervals showed texture may not consistently provide beneficial results across studies for all outcomes: COP displacement EC (-0.61 to 2.12), EO (-0.54 to 1.12), COP velocity EC (-0.27 to 0.68) and EO (-0.44 to 0.73).

SIGNIFICANCE

Overall, textured materials improved balance, but these effects were heterogeneous. This research may therefore inform applied investigations into balance improvements for healthy populations, for example, in functional movements and sports.

Plantar cutaneous afferents influence the perception of Subjective Visual Vertical in quiet stance

The estimation of Subjective Visual Vertical (SVV) involves the allocentric, gravitational and egocentric references, which are built by visual, vestibular and somatosensory afferents. Our goals were to assess the influence of plantar cutaneous afferents on the perception of SVV, and to see if there is a difference according to the efficiency of plantar cutaneous afferents. We recruited 48 young and healthy subjects and assessed their SVV and postural performances in quiet stance with a force platform, at 40 or 200 cm, in four ground conditions: on firm ground, on foam, with a bilateral, or with a unilateral 3 mm arch support. We also assessed the efficiency of our subjects' plantar afferents with the plantar quotient method and divided them in two groups: subjects with a normal use of plantar afferents and subjects with Plantar Exteroceptive Inefficiency (PEI). The results showed significant decreases in the counter clockwise SVV deviation only with the unilateral arch support, at near distance, and among the typically behaving subjects. We conclude that asymmetric foot cutaneous afferents are able to bias the egocentric vertical reference and hence influence the perception of SVV. This influence disappears among subjects with PEI, probably because of a distortion of the plantar signal.

Perceptual Aspects of Postural Control: Does Pure Proprioceptive Training Exist?

As proprioceptive training is popular for injury prevention and rehabilitation, we evaluated its effect on balance parameters and assessed the frequency spectra of postural sway linked with the various sensory channels. We recorded the Center of Mass displacement of 30 healthy student research participants (mean age = 21.63; SD = 1.29 years) with a single force plate under eyes open (EO) and eyes closed (EC) positions while standing on either a firm or foam surface, both before and after an 8-week balance training intervention on a foam surface with EC. We subjected the data to frequency power spectral analysis to find any differences between the frequency bands, linked with various sensory data. On the foam surface in the EC condition, the sway path decreased significantly after proprioceptive training, but, on the firm surface in the EC condition, there was no change. On the foam surface in the EC condition, there was also a significant decrease in frequency power postproprioceptive training in the medium-to-low frequency band. While our data indicate better posttraining balance skills, improvements were task specific to the trained condition, with no transfer of the acquired skill, even to a similar, easier condition. As training improved the middle-low frequency band, linked with vestibular signals, this intervention is better described as balance than "proprioceptive" training.

Manipulation of the body schema - Unilateral manual stimulation of lower extremity influences weight distribution in standing position

Clinical experience advocates sensory stimulation to increase the body sensation and adjust the body schema, which may be disturbed in some patients. Unilateral massage may affect the body midline orientation, but little evidence is available to support the effect of this practice. Twenty-one healthy young people participated in this experimental study. Two force plates measured weight distribution between the legs in standing position before and after unilateral manual stimulation of the lower extremities. Stimulation of the leg with initial least weight-bearing increased the load on this leg significantly from 48.2% to 49.0% and a similar but reverse effect was seen when stimulating the contra-lateral leg. When analysing the data with respect to stimulation of the non-dominant leg, the stimulation increased the weight-bearing on this leg from 49.6% to 51.3%. These findings indicate that external afferent stimuli may enhance the body perception and influence the body schema and midline orientation.

Plantar Exteroceptive Inefficiency causes an asynergic use of plantar and visual afferents for postural control: Best means of remediation

INTRODUCTION

Some subjects have difficulty to integrate both visual and plantar inputs, showing at the same time a "postural blindness" and a Plantar Exteroceptive Inefficiency (PEI). The former corresponds to a better stability eyes closed (EC) than eyes open (EO), while the latter is defined as a better stability on foam than on firm ground. Clinical studies reported that a manipulation of either plantar or visual input could affect the weight of both cues in postural control, suggesting interdependence in their use. The purpose of the experiment is to characterize the PEI phenomenon better and see if such synergy can be objectified.

METHODS

We recruited 48 subjects (25 ± 3.3 years) and assessed their balance with a force platform, EO, EC, at 40 or 200 cm, on firm ground, Dépron^® foam, Dynachoc^® foam, or on a 3 mm-thick Anterior Bar AB^®. We assessed their sensorial preferences through their PQ and RQ.

RESULTS

The main results are that there normally exists a synergy in the use of plantar and visual afferents, but only at 40 cm and in the absence of PEI.

CONCLUSIONS

Plantar Exteroceptive Inefficiency interferes with the role of vision in postural control, its effects are distance specific, are better revealed by Dépron^® foam and the AB^® improves posture but does not solve visual-podal asynergy. These results also have clinical interests as they indicate the best way in terms of distance and choice of foam to diagnostic PEI. Finally, they suggest restricting the use of the AB^®, commonly employed. These findings can be useful for clinicians concerned with foot, eye, and posture.

Effects of different lower-limb sensory stimulation strategies on postural regulation-A systematic review and meta-analysis

Systematic reviews of balance control have tended to only focus on the effects of single lower-limb stimulation strategies, and a current limitation is the lack of comparison between different relevant stimulation strategies. The aim of this systematic review and meta-analysis was to examine evidence of effects of different lower-limb sensory stimulation strategies on postural regulation and stability. Moderate- to high- pooled effect sizes (Unbiased (Hedges’ g) standardized mean differences (SMD) = 0.31–0.66) were observed with the addition of noise in a Stochastic Resonance Stimulation Strategy (SRSS), in three populations (i.e., healthy young adults, older adults, and individuals with lower-limb injuries), and under different task constraints (i.e., unipedal, bipedal, and eyes open). A Textured Material Stimulation Strategy (TMSS) enhanced postural control in the most challenging condition—eyes-closed on a stable surface (SMD = 0.61), and in older adults (SMD = 0.30). The Wearable Garments Stimulation Strategy (WGSS) showed no or adverse effects (SMD = -0.68–0.05) under all task constraints and in all populations, except in individuals with lower-limb injuries (SMD = 0.20). Results of our systematic review and meta-analysis revealed that future research could consider combining two or more stimulation strategies in intervention treatments for postural regulation and balance problems, depending on individual needs.

The short-term effects of trigger point therapy, stretching and medicine ball exercises on accuracy and back swing hip turn in elite, male golfers - A randomised controlled trial

OBJECTIVES

This study aimed to compare the effect of myofascial trigger point therapy (MTPT) and stretching, MTPT and medicine ball exercises, and no intervention, on hip flexor length (HFL), golf swing biomechanics and performance in elite, male golfers.

DESIGN

Single blind, randomised controlled trial with two experimental groups (stretch group: MTPT and stretching; and the ball group: MTPT, a single stretch and medicine ball exercises) and one control group (no intervention).

SETTING

Professional golf academy.

PARTICIPANTS

One hundred, elite, male golfers aged 16-25 years.

MAIN OUTCOME MEASURES

HFL, 3D biomechanical analysis of the golf swing, club head speed (CHS), smash ratio, accuracy and distance at baseline and after the interventions.

RESULTS

Backswing hip turn (BSHT) improved in the ball group relative to the control group (p = 0.0248). Accuracy in the ball group and the stretch group improved relative to the control group (Fisher's exact = 0.016).

CONCLUSIONS

Other performance parameters such as: smash ratio, distance and CHS were not compromised by either intervention. This study advocates the use of MTPT combined with medicine ball exercises over MTPT combined with stretching in the treatment of golfers with shortened hip flexors - even immediately preceding a tournament.

Postural control in degenerative diseases of the hip joint

BACKGROUND

Few studies investigated the postural control in patients with hip joint impairments; in some cases, balance impairments have been found, while other researchers have seen no significant changes. The goal of this study was to characterize postural stability in patients suffering from unilateral osteoarthritis or rheumatoid arthritis in different balance tasks and to reveal potential differences between the two diseases in this respect.

METHODS

Ten patients with hip osteoarthritis (mean age: 62.3years), 10 patients with rheumatoid arthritis (mean age: 55.4years) and 10 healthy control subjects (mean age: 54.3years) took part in the study. Displacement of centre of pressure was measured with a force plate in mediolateral and anteroposterior directions during two-leg standing on firm and compliant surfaces with eyes opened and closed.

FINDINGS

Standing on a firm surface sway path increased significantly in the anteroposterior direction in both patient groups and in the mediolateral direction in all groups with eyes closed as compared to eyes opened condition. Standing on a compliant surface, sway paths increased significantly in both directions in all groups with eyes closed as compared to eyes opened condition; furthermore, sway paths were significantly longer with eyes closed in patients with rheumatoid arthritis in comparison with control and osteoarthritis groups.

INTERPRETATION

Our data revealed that the manipulation of both visual and somatosensory information can reveal subtle impairments in balance control. Thus, this paradigm can unmask the effects of decreased proprioception due to joint capsule lesion in patients with rheumatoid arthritis.

Comparisons of the effects of a foam pad, mung bean bag, and plastic bead bag on postural stability disturbance in healthy young adults

[Purpose] The aim of the present study was to compare the effects of unstable support surfaces, i.e. foam pad, mung bean bag, and plastic bead bag, on postural stability disturbance. [Subjects and Methods] Twenty-two healthy young adults (11 male and 11 female; aged 21.09 ± 1.44 years; BMI 20.40 ± 1.40 kg/m²) participated in the study. The Balance Master™ was used to evaluate the limit of stability and the unilateral stance performance. Each participant was assessed while standing on the following surfaces: 1) a firm surface, 2) a foam pad, 3) a mung bean bag, and 4) a plastic bead bag. The order of surfaces was randomly assigned. [Results] The mung bean bag and plastic bead bag showed greater disturbances in limit of stability and unilateral stance than the foam pad. There was no significant difference in postural stability disturbance between the mung bean bag and plastic bead bag. [Conclusion] These results suggested that both the mung bean bag and plastic bead bag could be used as a low-cost tool for balance assessment instead of a foam pad in healthy young adults.

Reliability of modified sensory interaction test as measured with force platform

The test-retest reliability of the modified sensory interaction test on a force platform was performed in a group of 26 young and 15 elderly females for four sensory conditions: standing on firm and compliant surface with eyes open and closed. The test-retest reliability was good to excellent in both groups, with higher level of test-retest reliability in more demanding conditions. The most reliable time-domain variables for standing on firm surface with eyes open were: sway area from principal components (ICC = 0.77) for young and mean velocity, medio-lateral and total path lengths (ICC = 0.91) for elderly. For eyes closed, the most reliable variables were antero-posterior path length and sway area calculated by Fourier coefficients (ICC = 0.85) for young and medio-lateral path length (ICC = 0.93) for elderly. For compliant surface with open eyes, the most reliable variable was medio-lateral variability (ICC = 0.83) for young and total path length and mean velocity (ICC = 0.92) for elderly participants, whereas for eyes closed the most reliable variables were mean velocity, total and medio-lateral path lengths for young, and mean velocity for elderly group, all with ICC = 0.90. Modified sensory interaction test is therefore a reliable measure for balance and could be recommended as an outcome measure for balance retraining programmes.

The role of textured material in supporting perceptual-motor functions

Simple deformation of the skin surface with textured materials can improve human perceptual-motor performance. The implications of these findings are inexpensive, adaptable and easily integrated clothing, equipment and tools for improving perceptual-motor functionality. However, some clarification is needed because mixed results have been reported in the literature, highlighting positive, absent and/or negative effects of added texture on measures of perceptual-motor performance. Therefore the aim of this study was to evaluate the efficacy of textured materials for enhancing perceptual-motor functionality. The systematic review uncovered two variables suitable for sub-group analysis within and between studies: participant age (groupings were 18–51 years and 64.7–79.4 years) and experimental task (upright balance and walking). Evaluation of studies that observed texture effects during upright balance tasks, uncovered two additional candidate sub-groups for future work: vision (eyes open and eyes closed) and stability (stable and unstable). Meta-analysis (random effects) revealed that young participants improve performance by a small to moderate amount in upright balance tasks with added texture (SMD = 0.28, 95%CI = 0.46–0.09, Z = 2.99, P = 0.001; Tau² = 0.02; Chi² = 9.87, df = 6, P = 0.13; I² = 39.22). Significant heterogeneity was found in, the overall effect of texture: Tau² = 0.13; Chi² = 130.71, df = 26, P<0.0001; I² = 85.98%, pooled samples in upright balance tasks: Tau² = 0.09; Chi² = 101.57, df = 13, P<0.001; I² = 72.67%, and in elderly in upright balance tasks: Tau² = 0.16; Chi² = 39.42, df = 5, P<0.001; I² = 83.05%. No effect was shown for walking tasks: Tau² = 0.00; Chi² = 3.45, df = 4, P = 0.27, I² = 22.99%. Data provides unequivocal support for utilizing textured materials in young healthy populations for improving perceptual-motor performance. Future research is needed in young healthy populations under conditions where visual and proprioceptive information is challenged, as in high-speed movements, or where use of equipment mediates the performer-environment interaction or where dysfunctional information sources ‘compete’ for attention. In elderly and ailing populations data suggests further research is required to better understand contexts where texture can facilitate improved perceptual-motor performance.