Changing the texture of footwear can alter gait patterns

The suppression of lower leg electromyography when walking in textured foot orthoses

Previous research exploring the effects of tactile feedback in standing balance protocols may have generated results that misrepresent the modulatory capabilities of cutaneous afference on generating motor output responses. The neurosensory mechanism of textured foot orthoses to maximize the activation of cutaneous mechanoreceptors is through repetitive foot sole skin indentation. Thus, the purpose of this experimental protocol was to investigate muscular activity amplitude changes during the stance phase of gait, specifically when walking on level ground and when stepping onto a raised wedge, and while wearing textured foot orthoses compared to orthoses without texture. Twenty-one healthy young adults were fit to a standardized neutral running shoe and completed five level and wedged walking trials wearing both orthoses. Kinematic, kinetic and electromyography (EMG) data were recorded from eight lower limb muscles. The results of this study revealed EMG suppression of lower leg musculature during stance when walking in textured foot orthoses, and this was most pronounced when lower leg musculature is typically most active. The addition of texture in foot orthoses design, spanning the entire length of the foot sole, appears to be a clear mechanism to modulate neurosensory feedback with intent to suppress EMG of shank musculature during gait.

Impact of textured surfaces on the orthostatic balance of patients with multiple sclerosis

OBJECTIVE

To perform posturographic measurements with eyes open or closed using floor coverings with different textured surfaces to study postural control in patients with multiple sclerosis (MS).

METHODS

Static posturographic recordings were performed with eyes open and eyes closed on a forceplate with no covering (control condition) or covered by a textured mat with small pimples (height 2 mm) or large pimples (height 7 mm). Several posturographic variables were measured, focusing on displacements of the center of pressure (CoP) including the average velocity (Vav), the total length (L) of all displacements, and the surface (S) of the confidence ellipse. The recordings made with the textured mats were compared to the control condition with eyes open or closed. Then, the differences between the recordings made with large vs. small pimples on the one hand, and with eyes closed vs. open were calculated to assess the impact of pimple height or eye closure on posturographic measurements. Clinical assessment was based on the Expanded Disability Status Scale (EDSS) and its functional system (FS) subscores, the Modified Fatigue Impact Scale (MFIS), the Unipodal Stance test (UST), and the Timed Up-and-Go test (TUG).

RESULTS

Forty-six MS patients (mean EDSS score: 3.6) completed the study. Several posturographic variables, including Vav and L, deteriorated when measured on a textured mat, especially with large pimples and in eyes open condition. In contrast, no difference was found with small pimples and eyes closed, as compared to the control condition (no covering). The deleterious impact of pimple height on posturography correlated positively with the alteration of balance and gait clinically assessed by the UST and the TUG, and also with the MFIS physical and cerebral EDSS-FS subscores, and negatively with the cerebellar and brainstem subscores. On the other hand, the impact of eye closure on posturography was negatively correlated with the visual EDSS-FS subscore.

DISCUSSION

Static posturographic measurements made with different textured surfaces and visual conditions can be considered as a sensitive tool to measure "proprioceptive reserves". Actually, when cerebellar, brainstem, or visual functions are impaired, the resources of the sensory (proprioceptive) system, if preserved, can be recruited at a higher level and compensate for dysfunctions of other postural controls to maintain a satisfactory balance. In addition, this procedure of static posturographic examination can provide objective measurements correlated with clinical testing of balance and gait and could usefully complement EDSS scoring to assess disability affecting postural control and the risk of falling in MS patients.

Capitalizing on skin in orthotics design: the effects of texture on plantar intrinsic foot muscles during locomotion

Foot orthoses (FO) are a commonly prescribed intervention to alter foot function during walking although their effects have been primarily studied in the extrinsic muscles of the foot. Furthermore, enhancing sensory feedback under the foot sole has been recently shown to alter extrinsic muscle activity during gait; however, the effects of FOs with enhanced sensory feedback on plantar intrinsic foot muscles (PIFMs) remain unknown. Thus, the purpose of this study was to investigate the effect of FOs with and without sensory facilitation on PIFM activity during locomotion. Forty healthy adults completed a series of gait trials in non-textured and textured FOs when walking over hard and soft flooring. Outcome measures included bilateral joint kinematics and electromyography (EMG) of four PIFMs. Results of this study highlight the distinct onset and cessations of each PIFM throughout the stance phase of gait. PIFMs remained active during mid-stance when wearing FOs and textured FOs facilitated muscle activity across the stance phase of gait. Increasing cutaneous input from foot sole skin, via the addition of texture under the foot sole, appears to alter motor-neuron pool excitation of PIFMs. Future academics are encouraged to increase our understanding on which pathologies, diseases, and/or medical conditions would best benefit from textured FOs.

The topographical attenuation of cutaneous input is modulated at the ankle joint during gait

The attenuation of sensory inputs via various methods has been demonstrated to impair balance control and alter locomotor behavior during human walking; however, the effects of attenuating foot sole sensation under distinct areas of the foot sole on lower extremity motor output remains poorly understood. Thus, the purpose of this study was to attenuate cutaneous feedback via regional hypothermia under five different areas of the foot sole and investigate the resultant modulation of kinematic and muscle activity during level walking. Electromyography from eight lower leg muscles, kinematics, and location of center of pressure was recorded from 48 healthy young adults completing walking trials with normal and reduced cutaneous sensation from bilateral foot soles. The results of this study highlight the modulatory response of the tibialis anterior in terminal stance (propulsion and toe-off) and medial gastrocnemius muscle throughout the entire stance phase of gait. The topographical organization of foot sole skin in response to the attenuation of cutaneous feedback from different areas of the foot sole significantly modified locomotor activity. Furthermore, the locomotor response to cutaneous attenuation under the same regions that we previously facilitated with tactile feedback do not oppose each other, suggesting different physiological changes to foot sole skin generate unique gait behaviors.

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.

Effects of wearing textured versus smooth shoe insoles for 12 weeks on gait, foot sensation and patient-reported outcomes, in people with multiple sclerosis: a randomised controlled trial

BACKGROUND

Innovative shoe insoles, designed to enhance sensory information on the plantar surface of the feet, could help to improve walking in people with Multiple Sclerosis.

OBJECTIVE

To compare the effects of wearing textured versus smooth insoles, on measures of gait, foot sensation and patient-reported outcomes, in people with Multiple Sclerosis.

METHODS

A prospective, randomised controlled trial was conducted with concealed allocation, assessor blinding and intention-to-treat analysis. Thirty ambulant men and women with multiple sclerosis (MS) (Disease Steps rating 1-4) were randomly allocated to wear textured or smooth insoles for 12 weeks. Self-reported insole wear and falls diaries were completed over the intervention period. Laboratory assessments of spatiotemporal gait patterns, foot sensation and proprioception, and patient-reported outcomes, were performed at Weeks 0 (Baseline 1), 4 (Baseline 2) and 16 (Post-Intervention). The primary outcome was the size of the mediolateral base of support (stride/step width) when walking over even and uneven surfaces. Independent t-tests were performed on change from baseline (average of baseline measures) to post-intervention.

RESULTS

There were no differences in stride width between groups, when walking over the even or uneven surfaces (P ≥ 0.20) at post-intervention. There were no between-group differences for any secondary outcomes including gait (all P values > 0.23), foot sensory function (all P values ≥ 0.08) and patient-reported outcomes (all P values ≥ 0.23).

CONCLUSIONS

In our small trial, prolonged wear of textured insoles did not appear to alter walking or foot sensation in people with MS who have limited foot sensory loss. Further investigation is needed to explore optimal insole design.

CLINICAL TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry (ACTRN12615000421538).

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

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

Acute Effects of a Haptic Anchor System on Postural Sway of Individuals with Parkinson's Disease: A Preliminary Study

Some investigators have demonstrated that an anchor system can improve postural control in elderly persons during balance tasks, but none have reported on the use of this approach in individuals with Parkinson's disease (PD). Therefore, we aimed to evaluate the effect of an anchor system on postural sway in elderly individuals with (n = 13) and without (n = 14) PD. In this cross-sectional study, we measured postural sway with a force platform based on the Clinical Test of Sensory Interaction of Balance (CTSIB). We calculated center of pressure (COP) parameters, as a function of time, based on the ellipse sway area (cm²) and evaluated self-efficacy for postural control based on the degree of difficulty in each task. With the anchor system (i.e., handheld ropes attached to weights on the floor), we observed a significant reduction in the ellipse sway area in the semi-tandem position among individuals with PD (p = .04). For participants without PD, there was no significant difference in sway with or without the anchor system in all positions. Also, for participants with PD, there was an improvement in self-efficacy for postural control associated with the anchor system in several positions while there was only a self-efficacy improvement with the anchor system in the semi-tandem position for those without PD. Acute use of a haptic anchor system reduced postural sway in the semi-tandem position in individuals with PD, and the anchor system generally improved postural control self-efficacy for body sway in individuals with PD.

The effects of foot orthoses and sensory facilitation on lower limb electromyography: A scoping review

Foot orthoses (FO) are used as a treatment for biomechanical abnormalities, overuse injuries, and neuropathologies, but study of their mechanism remains inconclusive. The neuromotor paradigm has proposed that FOs may manipulate sensory input from foot sole skin to reduce muscle activity for movement optimization. This review argues that a FO likely alters the incoming mechanical stimuli transmitted via cutaneous mechanoreceptors and nociceptors as the foot sole interfaces with the surface of the orthotic. Thus, all FOs with or without intentional sensory facilitation, likely changes sensory information from foot sole cutaneous afferents. Additionally, in light of understanding and applying knowledge pertaining to the cutaneous reflex loop circuitry, FO's increasing sensory input to the motorneuron pool can change EMG to either reflex sign (increase or decrease). The purpose of this scoping review was to synthesize FO and sensory augmentation literature and summarize how FO designs can capitalize on foot sole skin to modulate lower limb electromyography (EMG). Six database searches resulted in 30 FO studies and 22 sensory studies that included EMG as an outcome measure. Results revealed task and phase specific responses with some consistencies in EMG outcomes between testing modalities, however many inconsistencies remain. Electrical stimulation reflex research provides support for a likely sensory-to-motor factor contributing to muscle activity modulation when wearing FOs. The discussion divides trends in FO treatment modalities by desired increase or decrease in each compartment musculature. The results of this review provides a benchmark for future academics and clinicians to advance literature in support of a revised neuromotor paradigm while highlighting the importance of foot sole skin in FO design.

Effect of work boot shaft stiffness and sole flexibility on boot clearance and shank muscle activity when walking on simulated coal mining surfaces: implications for reducing trip risk

Mining work boot shaft stiffness and sole flexibility variations are likely to affect how a miner moves their foot to clear the ground thus influencing their risk of tripping. Despite the potential negative consequences associated with tripping, limited research has investigated how these boot design features might contribute to a miner's trip risk. Therefore, this study aimed to investigate the effects of systematic variations to boot shaft stiffness and sole flexibility on lower limb alignment and shank muscle activity at toe off and boot clearance during initial swing when 20 males walked across two simulated coal mining surfaces. Although knee and hip alignment remained constant, changes to boot shaft stiffness and sole flexibility significantly interacted to influence the shank muscle activity and ankle alignment displayed at toe off. To reduce the risk of tripping, underground coal miners should avoid a boot with a stiff shaft, regardless of the sole flexibility.

The effect of texture under distinct regions of the foot sole on human locomotion

Sensory feedback from the foot sole plays an important role in shaping human locomotion. While net muscle activity and kinematic changes have been correlated with electrical stimulation to five topographical regions of the foot, it remains unknown if these responses are similar with tactile stimulation. The purpose of this study was to use texture in foot orthosis design, applied to five distinct regions under the foot sole, and measure joint kinematics, location of center of pressure, and muscle activity of eight lower leg muscles during level and incline walking. Fifty-five healthy adults completed 48 walking trials in textured and non-textured foot orthoses. Study results confirm that tactile stimulation is stimulation-site and gait-phase specific in modulating lower leg muscle activity during walking. For example, texture under the lateral forefoot consistently generated a suppression of EMG and texture under the lateral midfoot always generated a facilitation. In early stance, adding texture under the medial midfoot or calcaneus facilitated extensor muscle activity and suppressed flexor muscle activity. Texture under the lateral midfoot or medial forefoot facilitated tibialis posterior activation. These results support the topographical organization of cutaneous mechanoreceptors in foot sole skin while considering how texture can be used in foot orthosis design to target lower leg muscular changes during locomotion.

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

BACKGROUND

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

RESEARCH QUESTION

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

METHODS

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

RESULTS

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

SIGNIFICANCE

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

Racial differences in running and landing measures associated with injury risk vary by sex

It is unknown whether running and landing mechanics differ between racial groups despite injury disparities between African Americans (AA) and white Americans (WA). This study aimed to identify potential racial differences in running and landing mechanics and understand whether anthropometric, strength, and health status factors contribute to these differences. Venous blood samples, anthropometry, lower-extremity strength, and health status assessments were collected (n = 84, 18-30y). Three-dimensional motion capture and force plate data were recorded during 7 running and 7 drop vertical jump trials. Racial effects were determined, and regression models evaluated explanatory factors. AA females ran with longer stance times (p = 0.003) than WA females, while AA males ran with smaller loading rates (p = 0.046) and larger peak vertical ground reaction forces (p = 0.036) than WA males. Frontal plane knee range of motion during landing was greater in AA females (p = 0.033) than WA females; larger waist circumference and weaker knee extension strength accounted for this significance. Although outcome measures were associated with physiologic, anthropometric, and activity measures, their explanatory power for race was ambiguous, except for knee range of motion in females. Modifiable factors explaining racial effects during landing in females are potential intervention targets to reduce racial health disparities in running and landing injuries.

Recreational runners who recovered from COVID-19 show different running kinetics and muscle activities compared with healthy controls

BACKGROUND

Social isolation through quarantine represents an effective means to prevent COVID-19 infection. A negative side-effect of quarantine is low physical activity.

RESEARCH QUESTION

What are the differences of running kinetics and muscle activities of recreational runners with a history of COVID-19 versus healthy controls?

METHODS

Forty men and women aged 20-30 years participated in this study and were divided into two experimental groups. Group 1 (age: 24.1 ± 2.9) consisted of participants with a history of COVID-19 (COVID group) and group 2 (age: 24.2 ± 2.7) of healthy age and sex-matched controls (controls). Both groups were tested for their running kinetics using a force plate and electromyographic activities (i.e., tibialis anterior [TA], gastrocnemius medialis [Gas-M], biceps femoris [BF], semitendinosus [ST], vastus lateralis [VL], vastus medialis [VM], rectus femoris [RF], gluteus medius [Glut-M]).

RESULTS

Results demonstrated higher peak vertical (p = 0.029; d=0.788) and medial (p = 0.004; d=1.119) ground reaction forces (GRFs) during push-off in COVID individuals compared with controls. Moreover, higher peak lateral GRFs were found during heel contact (p = 0.001; d=1.536) in the COVID group. COVID-19 individuals showed a shorter time-to-reach the peak vertical (p = 0.001; d=3.779) and posterior GRFs (p = 0.005; d=1.099) during heel contact. Moreover, the COVID group showed higher Gas-M (p = 0.007; d=1.109) and lower VM activity (p = 0.026; d=0.811) at heel contact.

SIGNIFICANCE

Different running kinetics and muscle activities were found in COVID-19 individuals versus healthy controls. Therefore, practitioners and therapists are advised to implement balance and/or strength training to improve lower limbs alignment and mediolateral control during dynamic movements in runners who recovered from COVID-19.

Effect of textured foot orthoses on walking plantar pressure variables in children with autism spectrum disorders

The aim of this study was to evaluate the effect of textured foot orthoses on plantar pressure variables in children with autism spectrum disorders (ASDs). Thirty boys were divided into two groups based on their health status, namely: autism spectrum disorder and healthy matched controls. Plantar pressure data were captured during stance phases of shod walking with and without textured foot orthoses. Remarkably larger peak force under the toe1 and metatarsal1 and peak pressure under the toe1 and toe2-5 regions were observed in the autism group comparing with the healthy group, while lower peak force under the toe1, metatarsal1 and metatarsal2 were seen during walking with textured foot orthoses comparing with the cases of walking without them. The results showed higher values of peak pressure under metatarsal3, metatarsal4 and metatarsal5 for the textured foot orthoses walking against the cases without them. Also, analysis depicted huge reductions from pre-to-posttest for the peak pressure under toe2-5 only cases within the autism group. The reason of observing higher peak values of forces and pressures within their forefoot can potentially be their tendency to walk on their toes comparing against the healthy control children. This causes lower pressure values within all toes and the first metatarsal regions during normal walking with textured foot orthoses than walking without them. The findings revealed that the use of textured foot orthoses reduced peak pressure under toe2-5 only in the autism group. This suggests that the use of such interventions can help boys with ASDs move more safely.

Effect of osteopathic manipulation on gait asymmetry

CONTEXT

Movement and loading asymmetry are associated with an increased risk of musculoskeletal injury, disease progression, and suboptimal recovery. Osteopathic structural screening can be utilized to determine areas of somatic dysfunction that could contribute to movement and loading asymmetry. Osteopathic manipulation treatments (OMTs) targeting identified somatic dysfunctions can correct structural asymmetries and malalignment, restoring the ability for proper compensation of stresses throughout the body. Little is currently known about the ability for OMTs to reduce gait asymmetries, thereby reducing the risk of injury, accelerated disease progression, and suboptimal recovery.

OBJECTIVES

To demonstrate whether osteopathic screening and treatment could alter movement and loading asymmetry during treadmill walking.

METHODS

Forty-two healthy adults (20 males, 22 females) between the ages of 18 and 35 were recruited for this prospective intervention. Standardized osteopathic screening exams were completed by a single physician for each participant, and osteopathic manipulation was performed targeting somatic dysfunctions identified in the screening exam. Three-dimensional (3-D) biomechanical assessments, including the collection of motion capture and force plate data, were performed prior to and following osteopathic manipulation to quantify gait mechanics. Motion capture and loading data were processed utilizing Qualisys Track Manager and Visual 3D software, respectively. Asymmetry in the following temporal, kinetic, and kinematic measures was quantified utilizing a limb symmetry index (LSI): peak vertical ground reaction force, the impulse of the vertical ground reaction force, peak knee flexion angle, step length, stride length, and stance time. A 2-way repeated-measures analysis of variance model was utilized to evaluate the effects of time (pre/post manipulation) and sex (male/female) on each measure of gait asymmetry.

RESULTS

Gait asymmetry in the peak vertical ground reaction force (-0.6%, p=0.025) and the impulse of the vertical ground reaction force (-0.3%, p=0.026) was reduced in males following osteopathic manipulation. There was no difference in gait asymmetry between time points in females. Osteopathic manipulation did not impact asymmetry in peak knee flexion angle, step length, stride length, or stance time. Among the participants, 59.5% (25) followed the common compensatory pattern, whereas 40.5% (17) followed the uncommon compensatory pattern. One third (33.3%, 14) of the participants showed decompensation at the occipitoatlantal (OA) junction, whereas 26.2% (11), one third (33.3%, 14), and 26.2% (11) showed decompensation at the cervicothoracic (CT), thoracolumbar (TL), and lumbosacral (LS) junctions, respectively. Somatic dysfunction at the sacrum, L5, right innominate, and left innominate occurred in 88.1% (37), 69.0% (29), 97.6% (41), and 97.6% (41) of the participants, respectively.

CONCLUSIONS

Correcting somatic dysfunction can influence gait asymmetry in males; the sex-specificity of the observed effects of osteopathic manipulation on gait asymmetry is worthy of further investigation. Osteopathic structural examinations and treatment of somatic dysfunctions may improve gait symmetry even in asymptomatic individuals. These findings encourage larger-scale investigations on the use of OMT to optimize gait, prevent injury and the progression of disease, and aid in recovery after surgery.

A shoe-insole to improve ankle joint mechanics for injury prevention among older adults

Technologies to assist senior individuals with active walking are important. This experiment aimed to investigate whether a customised insole geometry would reduce the risk of falls and locomotive injuries. The tested insole incorporated a built-in inclination to assist ankle dorsiflexion (2.2°) and eversion (4.5°). Twenty-six older adults and 30 younger counterparts undertook gait assessment with and without the experimental insole while 3 D motion capture and force plates recorded gait. The insole increased swing foot-ground clearance, with.43 cm for the older adults' dominant foot. The insole also prevented excessive lateral centre of pressure movement. The main insole effects on foot contact mechanics were (i) prolonged time to foot-flat (.015 s) and (ii) improved energy efficiency (2%). Reduced knee adduction moment (>15%) was observed in the older group. Shoe insoles to provide dorsiflexion and eversion support may have the potential to reduce the risk of falls and locomotion-related injuries for older adults.Practitioner Summary: Using 3 D gait assessment techniques this research investigated shoe-insoles incorporating ankle dorsiflexion and eversion support features. It was shown that falls risk and locomotive injuries could be reduced by the application of orthotics to support ankle dorsiflexion and eversion. Shoe-orthotics may provide practical low-cost solutions to correcting gait impairments.Abbreviations: MFC: minimum foot clearance; CoP: centre of pressure; OA: osteoarthritis; GRF: ground reaction forces; IREDS: infra-red light emitting diodes; PE: potential energy; KE: kinetic energy; IQR: interquartile range; ANOVA: analysis of variance.

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.

The effect of a textured insole on anticipatory postural adjustments

PURPOSE

To obtain preliminary data on the effect of a textured insole on postural control.

METHODS

Nine healthy subjects were exposed to external perturbations applied to their shoulders while standing with or without a single textured insole. Body weight distribution and bilateral electromyographic activity (EMG) of trunk and leg muscles were recorded. Onsets of EMG activity of muscles were calculated and analyzed within the interval typical for anticipatory postural adjustments.

RESULTS

When a textured insole was provided under one foot, subjects shifted their body weight towards the contralateral foot. With no insole, the anticipatory onsets of EMG activity of the left and right muscles were symmetrical; when a textured insole was used, the EMG onsets of the muscles on the contralateral side of the body were seen earlier as compared to the insole side. This early activation was more pronounced in the trunk muscles (p < 0.05).

CONCLUSIONS

Using a single textured insole under one-foot induced asymmetry of anticipatory onsets of EMG activity in healthy subjects. The outcome highlights the importance of investigating the role of a single textured insole in control of vertical posture and provides a foundation for future studies focussed on improvement of postural control in individuals with body asymmetry due to unilateral weakness.

The effect of age, sex and a firm-textured surface on postural control

In previous studies, the influence of plantar sensation has been examined using various textured surfaces with different stiffness materials to assess static balance. This study investigated the effects of a Firm Textured Surface (FTS) along with age and sex-related influences on postural control under different visual conditions. Forty subjects (20 elderly, 10 males, mean age 68.30, 10 females, mean age 68.00, and 20 young people, 10 males, mean age 25.45, 10 females, mean age 27.30) participated in this study maintained a quiet standing on FTS, foam and firm surfaces with eyes open and closed. The center of pressure displacement (CoP_DISP), CoP velocity (CoP_VEL), and sway velocity of the CoP in anteroposterior (AP) and mediolateral (ML) direction (V_A/P and V_M/L) were measured. FTS was associated with lower postural sway measures in both the groups with eyes open and closed. However, the foam surface showed the worst results in all postural parameters under all experimental conditions. Separate four-way ANOVAs were applied to each dependent variable. The main effects of surface (p < 0.0001), vision (p < 0.0001) and age (p < 0.0001 for CoP_DISP, CoP_VEL and V_A/P; p = 0.0003 for V_M/L) were significant in each of the four fitted models. Sex was never significant, either as a main effect or an interaction with other experimental factors. Eyes open were able to reduce the negative effects of the foam surfaces but without vision the proprioceptive sensory system cues of the body state become more important for maintaining balance. A good stimulation with rigid texture should be considered as relief to reduce the physiological-related decline of afferent information with age.

Physical performance and perception of foot discomfort during a soccer-specific match simulation. A comparison of football boots

Football boots are marketed with emphasis on a single key performance characteristic (e.g. speed). Little is known on how design parameters impact players' performance. This study investigated the impact of boot design on performance maintenance and perceived foot comfort during a 90-minute match simulation drill. Eleven male university football players tested two commercially available "sprint boots" known to generate significantly different plantar pressures (high=Boot H and low=Boot L) . Players completed a modified Soccer-specific Aerobic Field Test on a 3G pitch. Heart rate, rated perceived exertion and perceived foot discomfort were assessed for each 15-min interval. Power generation was assessed pre- and post-match simulation. A significantly higher mean heart rate was seen for Boot L in the 60th-75th and 75th-90th minute intervals (P = 0.017, P = 0.012 respectively). Perceived exertion did not differ between boots (P ≥ 0.302). Power generation significantly decreased in Boot H between pre- and post-match (P = 0.042). Both boots increased discomfort with significantly more plantar discomfort felt in the last 30 min in Boot H (75th min: P = 0.037; 90th min: P = 0.048). The results imply that a comfortable boot design may improve maintenance of performance during match-play.

The role of enhanced plantar-surface sensory feedback on lower limb EMG during planned gait termination

Purpose/aim of the study: Generation of smooth movement relies on the central nervous system (CNS) having information from the visual, vestibular and somatosensory systems to effectively execute motor behaviour. Recently, cutaneous afferent inputs have been linked to lower leg motorneuron pools, resulting in a growing interest of adding texture to the plantar foot sole interface as a novel method to facilitate cutaneous feedback. The aim of this study was to characterize the changes in magnitude and temporal organization of muscle activity, and to investigate motor output changes from enhanced tactile feedback during perturbed gait termination.Materials and methods: Thirty young adults experienced an unpredictable platform perturbation when completing planned gait termination. The study manipulated two experimental variables: 1) direction of platform tilt (anterior, posterior, medial, lateral), and 2) foot sensory facilitation (non-facilitated, facilitated). Upper and lower leg EMG onset, cessation time and integrated EMG (iEMG) were measured in addition to common gait parameters (walking velocity, step length, step width).Results: Gait termination over a textured surface resulted in significantly earlier upper leg EMG onset times and modified iEMG of rectus femoris, vastus medialis and biceps femoris muscles.Conclusions: Results of this study suggest that the addition of cutaneous feedback under the plantar-surface of the foot increases the ability to generate an earlier muscle response, consequently improving response ability to an unexpected perturbation. Secondly, enhanced tactile feedback appears to inform the CNS of the magnitude of the threat to the balance control system, providing additional insight into how the CNS uses enhanced tactile feedback during a gait termination task.

Effects of corrective insole on leg muscle activation and lower extremity alignment in rice farmers with pronated foot: a preliminary report

BACKGROUND

Execution of strenuous activities in conjunction with slippery and viscous muddy working terrain in rice cultivation leads to a high prevalence of farmer musculoskeletal disorders and malalignments. Recommended intervention strategies originally designed for congenitally disabled individuals may also be applicable to farmers, including simple corrective wedges to reduce foot eversion. The objective of the present study was to conduct a preliminary investigation of the effects of corrective wedges on lower extremity muscle activity and alignment when subjects stood on flat rigid ground or muddy terrain, simulating typical work conditions encountered by the unique but populous Thai rice farming workforce.

METHODS

Nine healthy farmers with pronated feet were recruited to participate and wedges were custom fabricated for each farmer based on physical therapy assessment and use of rapid prototyping techniques. Participants were asked to stand barefoot or with wedges on the two surface types.

RESULTS

Results revealed foot pronation and knee valgus to improve (ranging, on average between 5.5 and 16.1 degrees) when participants were equipped with corrective wedges. The muscle activity of the peroneus longus and the tibialis anterior increased for muddy terrain, as compared with the rigid surface. In general, the wedges induced less tibialis anterior activity and greater peroneus longus activity, compared to when participants were standing barefoot. An elevation in evertor muscle activity may reflect stretching of the shortened muscle as a result of the reduced degree of foot pronation.

CONCLUSIONS

Findings demonstrate potential benefits of corrective insole usage for farmers with pronated feet, including improved lower extremity alignment and invertor muscle activity reduction for both rigid and muddy terrains.

Biomechanical analysis of single-leg stance using a textured balance board compared to a smooth balance board and the floor: A cross-sectional study

BACKGROUND

Previous research showed that standing on textured surfaces can improve postural control by adapting somatosensory inputs from the plantar foot. The additional stimulation of plantar cutaneous mechanoreceptors by a textured surface during single-leg stance on a balance board may increase afferent information to the central nervous system to accelerate muscular responses and to enhance their accuracy. The additional impact of textured surface during single-leg stance on a balance board on postural control and muscle activity is unknown.

RESEARCH QUESTION

To investigate the differences of a) postural control during single-leg stance on a textured balance board compared to a smooth balance board and b) activity of lower extremity muscles during single-leg stance on a textured balance board compared to a smooth balance board and the floor.

METHODS

Twenty-six healthy adults (12 females, 14 males; mean age = 25.4 years) were asked to balance on their randomly assigned left or right leg on a force plate (floor; stable condition), a textured balance board and a smooth balance board (unstable conditions). Center of pressure (CoP) displacements (force plate, Bertec, 1000 Hz) and electromyographic activity (EMG) of eight leg muscles were measured and compared between conditions, respectively.

RESULTS

Neither CoP-displacements, nor EMG activities differed significantly between the textured and the smooth balance board (p > 0.05). Significantly higher muscle activities (p < 0.05) were observed using the balance boards compared to the floor.

SIGNIFICANCE

Single-leg stance using a textured balance board seems not to lead to reduced CoP-displacements compared to a smooth balance board. Muscle activation is significantly increased in both balance board conditions compared to the floor, however, it is not different when both balance board surfaces are compared. It could not be recommended to use a textured balance board for altering muscle activity and improving postural control during single-leg stance in favor of a smooth textured balance board.

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.

Racial differences in gait mechanics

The effect of race has rarely been investigated in biomechanics studies despite racial health disparities in the incidence of musculoskeletal injuries and disease, hindering both treatment and assessment of rehabilitation. The purpose of this study was to test the hypothesis that racial differences in gait mechanics exist between African Americans (AA) and white Americans (WA). Ninety-two participants (18-30 years old) were recruited with equal numbers in each racial group and sex. Self-selected walking speed was measured for each participant. 3D motion capture and force plate data were recorded during 7 walking trials at regular and fast set speeds. Step length, step width, peak vertical ground reaction force, peak hip extension, peak knee flexion, and peak ankle plantarflexion were computed for all trials at both set speeds. Multivariate and post-hoc univariate ANOVA models were fit to determine main and interaction effects of sex and race (SPSS V26, α = 0.05). Self-selected walking speed was slower in AA (p = 0.004, ƞ_p² = 0.088). No significant interactions between race and sex were identified. Males took longer steps (regular: p < 0.001, ƞ_p² = 0.288, fast: p < 0.001, ƞ_p² = 0.193) and had larger peak knee flexion (regular: p = 0.007, ƞ_p² = 0.081, fast: p < 0.001, ƞ_p² = 0.188) and ankle plantarflexion angles (regular: p = 0.050, ƞ_p² = 0.044, fast: p = 0.049, ƞ_p² = 0.044). Peak ankle plantarflexion angle (regular: p = 0.012, ƞ_p² = 0.071, fast: p < 0.001, ƞ_p² = 0.137) and peak hip extension angle during fast walking (p = 0.007, ƞ_p² = 0.083) were smaller in AA. Equivalency in gait measures between racial groups should not be assumed. Racially diverse study samples should be prioritized in the development of future research and individualized treatment protocols.

A Computational Internal Model to Quantify the Effect of Sensorimotor Augmentation on Motor Output

The aging process, as well as neurological disorders, causes a decline in sensorimotor functions, which can often bring degraded motor output. As a means of compensation for such sensorimotor deficiencies, sensorimotor augmentation has been actively investigated. Consequently, exoskeleton devices or functional electrical stimulation could augment the muscle activity, while textured surfaces or electrical nerve stimulations could augment the sensory feedback. However, it is not easy to precisely anticipate the effects of specific augmentation because sensory feedback and motor output interact with each other as a closed-loop operation via the central and peripheral nervous systems. A computational internal model can play a crucial role in anticipating such an effect of augmentation therapy on the motor outcome. Still, no existing internal sensorimotor loop model has been represented in a complete computational form facilitating the anticipation. This paper presents such a computational internal model, including numerical values representing the effect of sensorimotor augmentation. With the existing experimental results, the model performance was evaluated indirectly. The change of sensory gain affects motor output inversely, while the change of motor gain did not change or minimally affects the motor output.Clinical Relevance- The presented computational internal model will provide a simple and easy tool for clinicians to design therapeutic intervention using sensorimotor augmentation.

Effects of Metatarsal Work Boots on Gait During Level and Inclined Walking

Footwear plays an important role in worker safety. Work boots with safety toes are often utilized at mine sites to protect workers from hazards. Increasingly, mining operations require metatarsal guards in addition to safety toe protection in boots. While these guards provide additional protection, the impact of metatarsal guards on gait are unknown. This study aimed to measure the effects of 4 safety work boots, steel toe, and steel toe with metatarsal protection in wader- and hiker-style boots, on level and inclined walking gait characteristics, during ascent and descent. A total of 10 participants completed this study. A motion capture system measured kinematics that allowed for the calculation of key gait parameters. Results indicated that gait parameters changed due to incline, similar to previous literature. Wader-style work boots reduced ankle range of motion when ascending an incline. Hip, knee, and ankle ranges of motion were also reduced during descent for this style of boot. Wader-style boots with metatarsal guards led to the smallest ankle range of motion when descending an inclined walkway. From these results, it is likely that boot style affects gait parameters and may impact a miner's risk for slips, trips, or falls.

Effects of Artificial Texture Insoles and Foot Arches on Improving Arch Collapse in Flat Feet

The arches of the foot play a vital role in cushioning the impact and pressure generated from ground reaction forces due to body weight. Owing to a lack of normal human arch structure, people diagnosed as having flat feet often have discomfort in the soles of their feet. The results may not only cause inappropriate foot pressure distribution on the sole but also further cause foot injuries. This study heavily relies on a homemade foot pressure sensing device equipped with textured insoles of different heights and artificial arches. This was to explore the extent to which the pressure distribution of the foot in people with flat feet could be improved. A further comparison was made of the effects of using the textured insoles with different heights on two different groups of people diagnosed with flat and normal feet respectively. Sixty-five undergraduate and postgraduate volunteers were invited to receive the ink footprint test for measuring their degrees of arch index. Nine of these 65 had 2 flat feet, 3 had a left flat foot, 5 had a right flat foot, and 48 had 2 normal feet. To ensure the same number of subjects in both the control and the experimental groups, 9 of the 48 subjects who had normal feet were randomly selected. In total, 26 subjects (Male: 25, Female: 1; Age: 22 ± 1 years; height: 173.6 ± 2.5 cm; body mass: 68.3 ± 5.4 kg; BMI: 22.6 ± 1.2) were invited to participate in this foot pressure sensing insoles study. The experimental results showed that the use of textured insoles designed with different heights could not effectively improve the plantar pressure distribution and body stability in subjects with flat feet. Conversely, the use of an artificial arch effectively improved the excessive peak in pressure and poor body stability, and alleviated the problem of plantar collapse for patients with flat feet, especially in the inner part of their hallux and forefoot.

Obesity, but not overweight, is associated with plantar light touch sensation in children aged 8 to 16 years: A cross-sectional study

OBJECTIVE

Increased foot-ground contact loading engenders adaptive glabrous skin thickening and can decrease mechanoreceptor acuity and alter plantar cutaneous sensation. There has not been any research on whether overweight and obesity are similarly associated with normal plantar cutaneous sensation scores in children. This study investigated the associations between normal plantar cutaneous sensation scores and weight status (i.e., healthy weight, overweight, and obesity) in a sample of youth.

METHODS

Plantar sensation was tested among 122 participants aged 8 to 16 years (10.3 ± 1.8 years; 140.0 ± 11.2 cm; 44.2 ± 16.0 kg) across the forefoot, midfoot, and rearfoot using Semmes-Weinstein pressure aesthesiometry (0.07 g and 0.4 g monofilaments). Weight status was determined using the Centers for Disease Control and Prevention growth charts. Age- and sex-adjusted models were used to explore the relationships between normal plantar sensation scores and weight status. Significant two-tailed tests were set at p < .05.

RESULTS

Only obesity was inversely associated with normal plantar sensation scores on the left (β = -.241; p = .009) and right (β = -.222; p = .018) forefeet, left (β = -.322; p = .001) and right (β = -.253; p = .007) midfeet, and left (β = -.286; p = .002) and right (β = -.228; p = .014) wholefeet (relative to healthy weight) when using the 0.07 g monofilament. There was no association between obesity and plantar sensation when using the 0.4 g monofilament.

CONCLUSIONS

Obesity is associated with diminished light touch plantar sensation. Considering previously reported higher mechanical loading and the fact that Merkel cells and the Aβfibers that innervate them are superficial to the hypodermis, adaptive glabrous skin thickening (rather than fat pad thickness) may underlie this association. Contrary to previous suggestions, overweight is not associated with decreased plantar cutaneous sensation.

Effect of work boot shaft stiffness and sole flexibility on lower limb muscle activity and ankle alignment at initial foot-ground contact when walking on simulated coal mining surfaces: Implications for reducing slip risk

Design features of safety work boots have the potential to influence how underground coal miners' feet interact with the challenging surfaces they walk on and, in turn, their risk of slipping. Despite the importance of work boot design in reducing the risk of miners slipping, limited research has investigated how boot design features, such as shaft stiffness and sole flexibility, affect the way miners walk. Therefore, this study aimed to investigate the effects of systematic variations to boot shaft stiffness and sole flexibility on lower limb muscle activity and ankle motion in preparation for initial foot-ground contact when 20 males walked across two simulated coal mining surfaces under four mining boot conditions. It was concluded that a boot which has different flexibility and stiffness between the shaft and sole is a better design option to reduce underground coal miners' slip risk than a boot that has a stiff shaft and stiff sole or flexible shaft and flexible sole.

Can texture change joint position sense at the knee joint in those with poor joint position accuracy?

Purpose: Skin contributes to joint position sense (JPS) at multiple joints. Altered cutaneous input at the foot can modulate gait and balance and kinesiology tape can enhance proprioception at the knee, but its effect may be dependent on existing capacity. The effect of texture at the knee, particularly in those with poor proprioception, is unknown. The aim of this study was to determine the effect of textured panels on JPS about the knee. Materials and methods: Eighteen healthy females were seated in an adjustable chair. Their left leg (target limb) moved passively from 65° to a target of flexion (115° or 90°) or extension (40°). Their right leg (matching limb) was passively moved towards this target angle and participants indicated when their limbs felt aligned. We tested three textured panels over the knee of the matching limb and two control conditions. The target limb maintained a control panel. Directional error, absolute error and variable error in matching between limbs were calculated. Results: On average textured panels over the knee increased JPS error compared to control pants for participants with poor JPS. These participants undershot the target at 90° of flexion significantly more with textured panels (-11° ± 3°) versus control (-7° ± 3°, p = 0.04). Conclusions: For participants with poor JPS accuracy, increased JPS error at 90° with a textured panel suggests these individuals utilised altered cutaneous information to adjust joint position. We propose increased error results from enhanced skin input at the knee leading to the perception of increased flexion.

Footwear Alters Lower Extremity Coordination Variability

Footwear has been shown to have a significant effect on numerous kinematic and kinetic variables during walking and running. While footwear mass is an indisputably important influence on gait patterns, we suspected that the amount of outsole material on most footwear would likely diminish or delay the integration of tactile feedback in motor control strategies during gait. Thus, we designed this study to investigate the influence of footwear and augmented tactile feedback on lower extremity coordination patterns during walking. A secondary purpose of the study was to examine gender differences in response to altered footwear conditions. Forty-eight participants (24 male and 24 females) walked during four standardized footwear conditions (barefoot, shod, barefoot with augmented tactile feedback, and shod with augmented tactile feedback), and we collected three-dimensional kinematic data and calculated continuous relative phase values for two adjacent lower extremity joints to determine interjoint coordination patterns. We used deviation phase and the mean of the continuous relative phase to compare motor coordination patterns across conditions. We found significant footwear and gender effects for spatiotemporal variables but only significant footwear effects for motor coordination patterns. Females displayed a significantly higher cadence and shorter height-normalized stride length as compared to males. Participants displayed significantly greater thigh-shank coordination variability in the shod, as compared to the unshod, conditions. Thus, footwear results in a diminished or delayed tactile feedback that alters neuromuscular control strategies during walking.

Learning effect of dynamic postural stability evaluation system

BACKGROUND

Repeated exposure to a given perturbation of the postural control system has been shown to cause learning of more efficient postural strategies for maintaining balance both within a session and over time. It is important to show whether outcomes from treatment strategies are related to the effectiveness of training or are the result of the learning of the test process.

OBJECTIVE

To investigate the learning effect of the dynamic postural stability evaluation system.

METHODS

We studied 20 healthy young subjects (13 females and 7 males), with a mean age of 22.3 ± 1.9 years. Limits of stability and postural sway were assessed. All participants completed the standardized dynamic postural stability evaluation test (Bertec, Bertec Corporation, Columbus, OH, USA) seven times. The test was performed in both eyes open and eyes closed conditions.

RESULTS

There were differences in the limits of stability scores for backward (p= 0.042), left side (p= 0.05), and the total score (p= 0.04). There were significant differences in postural sway anteroposterior direction in perturbed surface with eyes closed condition (p= 0.004) and total limits of stability scores of perturbed surface with eyes closed condition (p= 0.046).

CONCLUSIONS

The study showed that balance test scores stabilized at different sessions from 1st to 3rd assessment period. Maximum normalized scores were reached at the third trial.

Effects of toe spreader on plantar pressure and gait in chronic stroke patients

BACKGROUND

The feet make the initial contact with the ground when walking and critically control both posture and gait. Claw toe, a structural change in the foot that may develop after stroke, triggers functional changes affecting both the lower limbs and balance.

OBJECTIVE

We analyzed the effects of a toe spreader on foot pressure and gait in chronic stroke patients.

METHODS

We enrolled 25 stroke patients. We used Gaitview AFA-50 and GAITRite instruments to measure plantar pressure distribution and gait with and without a toe spreader.

RESULTS

The average and rear foot pressures increased somewhat when a toe spreader was used. However, the differences were not significant in post hoc tests. In terms of gait, all variables significantly improved when the toe spreader was used.

CONCLUSIONS

A toe spreader may improve overall gait and spatiotemporal gait parameters in chronic stroke patients.

Wavelet analyses of electromyographic signals derived from lower extremity muscles while walking or running: A systematic review

Surface electromyography is often used to assess muscle activity and muscle function. A wavelet approach provides information about the intensity of muscle activity and motor unit recruitment strategies at every time point of the gait cycle. The aim was to review papers that employed wavelet analyses to investigate electromyograms of lower extremity muscles during walking and running. Eleven databases were searched up until June 1^st 2017. The composition was based on the PICO model and the PRISMA checklist. First author, year, subject characteristics, intervention, outcome measures & variables, results and wavelet specification were extracted. Eighteen studies included the use of wavelets to investigate electromyograms of lower extremity muscles. Three main topics were discussed: 1.) The capability of the method to correctly assign participants to a specific group (recognition rate) varied between 68.4%-100%. 2.) Patients with ankle osteoarthritis or total knee arthroplasty presented a delayed muscle activation in the early stance phase but a prolonged activation in mid stance. 3.) Atrophic muscles did not contain type II muscle fiber components but more energy in their lower frequencies. The simultaneous information of time, frequency and intensity is of high clinical relevance because it offers valuable information about pre-and reflex activation behavior on different walking and running speeds as well as spectral changes towards high or low frequencies at every time point of the gait cycle.

Effect of Different Insole Materials on Kinetic and Kinematic Variables of the Walking Gait in Healthy People

BACKGROUND

There is a lack of data that could address the effects of off-the-shelf insoles on gait variables in healthy people.

METHODS

Thirty-three healthy volunteers ranging in age from 18 to 35 years were included to this study. Kinematic and kinetic data were obtained in barefoot, shoe-only, steel insole, silicone insole, and polyurethane insole conditions using an optoelectronic three-dimensional motion analysis system. A repeated measures analysis of variance test was used to identify statistically significant differences between insole conditions. The alpha level was set at P < .05.

RESULTS

Maximum knee flexion was higher in the steel insole condition (P < .0001) compared with the silicone insole (P = .001) and shoe-only conditions (P = .032). Reduced maximum knee flexion was recorded in the polyurethane insole condition compared with the shoe-only condition (P = .031). Maximum knee flexion measured in the steel insole condition was higher compared to the barefoot condition (P = .020). Higher maximum ankle dorsiflexion was observed in the barefoot condition, and there were significant differences between the polyurethane insole (P < .0001), silicone insole (P = .001), steel insole (P = .002), and shoe conditions (P = .004). Least and highest maximum ankle plantarflexion were detected in the steel insole and silicone insole conditions, respectively. Maximum ankle plantarflexion in the barefoot and steel insole conditions (P = .014) and the barefoot and polyurethane insole conditions (P = .035) were significant. There was no significant difference between conditions for ground reaction force or joint moments.

CONCLUSIONS

Insoles made by different materials affect maximum knee flexion, maximum ankle dorsiflexion, and maximum ankle plantarflexion. This may be helpful during the decision-making process when selecting the insole material for any pathological conditions that require insole prescription.

Shoe-Insole Technology for Injury Prevention in Walking

Impaired walking increases injury risk during locomotion, including falls-related acute injuries and overuse damage to lower limb joints. Gait impairments seriously restrict voluntary, habitual engagement in injury prevention activities, such as recreational walking and exercise. There is, therefore, an urgent need for technology-based interventions for gait disorders that are cost effective, willingly taken-up, and provide immediate positive effects on walking. Gait control using shoe-insoles has potential as an effective population-based intervention, and new sensor technologies will enhance the effectiveness of these devices. Shoe-insole modifications include: (i) ankle joint support for falls prevention; (ii) shock absorption by utilising lower-resilience materials at the heel; (iii) improving reaction speed by stimulating cutaneous receptors; and (iv) preserving dynamic balance via foot centre of pressure control. Using sensor technology, such as in-shoe pressure measurement and motion capture systems, gait can be precisely monitored, allowing us to visualise how shoe-insoles change walking patterns. In addition, in-shoe systems, such as pressure monitoring and inertial sensors, can be incorporated into the insole to monitor gait in real-time. Inertial sensors coupled with in-shoe foot pressure sensors and global positioning systems (GPS) could be used to monitor spatiotemporal parameters in real-time. Real-time, online data management will enable &lsquo;big-data&rsquo; applications to everyday gait control characteristics.

The biomechanical effects and perceived comfort of textile-fabricated insoles during straight line walking

BACKGROUND

Orthotic insoles that are made of foam material often have less breathability and thus cause discomfort to the wearer. Given that a sandwich structure offers better porosity and breathability that would improve comfort, the impact of custom-made insoles made with three-dimensional spacer fabric is studied.

OBJECTIVES

To examine the biomechanical effects and subjective comfort of spacer-fabric insoles during walking.

STUDY DESIGN

Repeated measures.

METHODS

Plantar pressure and lower limb muscle activity data are collected from 12 subjects. Subjective perceived comfort is measured after five successful walking trials for each of the three different insoles worn: traditional insoles made with ethylene vinyl acetate and two types of spacer-fabric insoles.

RESULTS

Compared to the use of traditional insoles, there is a statistically significant reduction in the peak pressure (>8%) and pressure-time integral (>16%) in the toes and metatarsal head 1 with the use of the spacer-fabric insoles as the top layer. Insoles with two layers of spacer fabrics have the highest perceived comfort ( p < 0.01). However, there is no significant difference in the selected muscle activity for all three insoles.

CONCLUSION

Insoles with different arrangements of spacer fabrics allow changes in pressure patterns across the plantar foot and perception of comfort while walking. The findings enhance current understanding on the use of textile-fabricated materials, which provide alternative solutions for modifying insoles. Clinical relevance The key features of spacer fabric offer a viable option for different orthotic insole applications. The results will greatly contribute toward insole prescription, potentially enhancing the efficacy of orthotic performance and increasing the range of insole materials.

Gait characteristics in women's safety shoes

Although workers in Japan are required to wear safety footwear, there is concern about occupational accidents that occur when wearing safety shoes. This study aimed to analyze the effect of wearing hardsoled safety shoes on both spatiotemporal gait characteristics and the muscle activity in the lower extremities. Seventeen young women participated in this study. A 5-m gait trial and a surface electromyography trial were conducted while the women walked in either safety shoes or sports shoes. Paired t-tests were performed to analyze the differences in gait characteristics when walking in the two different pairs of shoes. Walking in safety shoes was associated with a significant increase in vastus lateralis, biceps femoris and tibialis anterior activity. This increased muscle activity in the lower extremities is likely compensating for the lower flexibility of the safety shoes.

Work boot design affects the way workers walk: A systematic review of the literature

Safety boots are compulsory in many occupations to protect the feet of workers from undesirable external stimuli, particularly in harsh work environments. The unique environmental conditions and varying tasks performed in different occupations necessitate a variety of boot designs to match each worker's occupational safety and functional requirements. Unfortunately, safety boots are often designed more for occupational safety at the expense of functionality and comfort. In fact, there is a paucity of published research investigating the influence that specific variations in work boot design have on fundamental tasks common to many occupations, such as walking. This literature review aimed to collate and examine what is currently known about the influence of boot design on walking in order to identify gaps in the literature and develop evidence-based recommendations upon which to design future research studies investigating work boot design.