The effects of enhanced plantar sensory feedback and foot orthoses on midfoot kinematics and lower leg neuromuscular activation

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

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

The 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.

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.

Are Three-Dimensional-Printed Foot Orthoses Able to Cover the Podiatric Physician's Needs?

BACKGROUND

Current management of foot pain requires foot orthoses (FOs) with various design features (eg, wedging, height) and specific mechanical properties (eg, hardness, volume). Development of additive manufacturing (three-dimensional [3-D] printing) raises the question of applying its technology to FO manufacturing. Recent studies have demonstrated the physical benefits of FO parts with specific mechanical properties, but none have investigated the relationship between honeycomb architecture (HcA) infilling density and Shore A hardness of thermoplastic polyurethane (TPU) used to make FOs, which is the aim of this study.

METHODS

Sixteen different FO samples were made with a 3-D printer using TPU (97 Shore A), with HcA infilling density ranging from 10 to 40. The mean of two Shore A hardness measurements was used in regression analysis.

RESULTS

Interdurometer reproducibility was excellent (intraclass correlation coefficient, 0.91; 95% confidence interval [CI], 0.64-0.98; P < .001) and interprinter reproducibility was excellent/good (intraclass correlation coefficient, 0.84; 95% CI, 0.43-0.96; P < .001). Linear regression showed a positive significant relationship between Shore A hardness and HcA infilling density (R2 = 0.955; P < .001). Concordance between evaluator and durometer was 86.7%.

CONCLUSIONS

This study revealed a strong relationship between Shore A hardness and HcA infilling density of TPU parts produced by 3-D printing and highlighted excellent concordance. These results are clinically relevant because 3-D printing can cover Shore A hardness values ranging from 40 to 70, representing most FO production needs. These results could provide important data for 3-D manufacturing of FOs to match the population needs.

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.

Effectiveness of a Double Air-Cushioned Shoe Compared with Physiotherapy in the Treatment of Plantar Fasciitis

Objective

This study was aimed at comparing the plantar fasciitis treatment effect of a double air-cushioned shoe to that of physiotherapy combined with ESWT.

Methods

Retrospective chart review of 40 patients diagnosed with plantar fasciitis was performed. Group 1 wore a double air-cushioned shoe for 2 months, and group 2 underwent physiotherapy with ESWT once/week over a 4-week period. The foot function index (FFI) score was obtained at the initial visit, 1 month, and 2 months.

Results

There were 25 patients in group 1 and 15 patients in group 2. The pretreatment FFI was 62.6 for group 1 and 50 for group 2. The 1-month posttreatment FFI was 45.6 for group 1 and 35.7 for group 2. The 2-month posttreatment FFI was 35 for group 1 and 43.1 for group 2. In both groups 1 and 2, follow-up FFIs were significantly improved from the initial FFI (p < 0.05) and there were no significant differences between two groups (p > 0.05).

Conclusions

The double air-cushioned shoe can be considered an alternative treatment option for noninvasive treatment of early-stage plantar fasciitis.

A systematic review of the effect of footwear, foot orthoses and taping on lower limb muscle activity during walking and running

BACKGROUND

External devices are used to manage musculoskeletal pathologies by altering loading of the foot, which could result in altered muscle activity that could have therapeutic benefits.

OBJECTIVES

To establish if evidence exists that footwear, foot orthoses and taping alter lower limb muscle activity during walking and running.

STUDY DESIGN

Systematic literature review.

METHODS

CINAHL, MEDLINE, ScienceDirect, SPORTDiscus and Web of Science databases were searched. Quality assessment was performed using guidelines for assessing healthcare interventions and electromyography methodology.

RESULTS

Thirty-one studies were included: 22 related to footwear, eight foot orthoses and one taping. In walking, (1) rocker footwear apparently decreases tibialis anterior activity and increases triceps surae activity, (2) orthoses could decrease activity of tibialis posterior and increase activity of peroneus longus and (3) other footwear and taping effects are unclear.

CONCLUSION

Modifications in shoe or orthosis design in the sagittal or frontal plane can alter activation in walking of muscles acting primarily in these planes. Adequately powered research with kinematic and kinetic data is needed to explain the presence/absence of changes in muscle activation with external devices.

CLINICAL RELEVANCE

This review provides some evidence that foot orthoses can reduce tibialis posterior activity, potentially benefitting specific musculoskeletal pathologies.

Full length foot orthoses have an immediate treatment effect and modify gait of children with idiopathic toe walking

BACKGROUND

There remains a substantial lack of evidence to support the use of foot orthoses as a conservative treatment option for idiopathic toe walking (ITW). Encouraging heel contact during gait is one of the primary goals of most interventions in paediatric ITW.

RESEARCH QUESTION

Does the combined treatment of high-top boots and orthoses increase the number of heel contacts during gait and change spatio-temporal gait parameters?

METHODS

This within subject designed randomised controlled trial recruited fifteen children diagnosed with ITW (n = 10 males). They were fitted with bilateral custom made rigid contoured carbon fibre foot orthoses placed inside high-top boots. To analyze the effect of this treatment, heel contacts and spatio-temporal parameters measured by an 8.3 m Gaitrite® mat were compared to barefoot walking and shod walking.

RESULTS

An immediate increase in heel contact (p = 0.021) was observed in the combined treatment only. Gait changes included a large increase in stride time in the combined treatment condition compared to barefoot walking (p = 0.006). This was associated with a decrease in the percentage of swing phase in the gait cycle (p < 0.010), an increase in stance phase (p < 0.010) and an increase in double support time (p < 0.001).

SIGNIFICANCE

These results suggest the hardness and thickness of the shoe and stiffness of the orthosis midsole may lead to improved local dynamic stability and foot position awareness with increased sensory feedback provided through the entire length of the foot. Further research is indicated to validate this treatment option on long term outcomes in this population group.

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.

Effect of insoles with arch support on gait pattern in patients with multiple sclerosis

Objectives

This study aims to determine the effect of insoles with arch support on gait patterns in patients with multiple sclerosis (MS) and somatosensory impairment.

Patients and methods

Ten patients (7 females, 3 males; mean age 34.9±6.8 years; range, 48 to 35 years) with clinically definite relapsing remitting MS and age- and sex-matched 10 healthy volunteers (7 females, 3 males; mean age 33.8±3.2; range, 40 to 31 years) were included in the study between January 2011 and January 2012. A medial longitudinal arch and transverse arch supporting polyurethane insole covered with foam shaped using plantar sensory feedback was used. Three-dimensional gait analysis was performed via a Vicon 612 system with six cameras. The participants initially walked barefoot and, then, wore the insoles in their short slipper socks.

Results

All participants were evaluated in terms of kinetics, kinematics, and temporospatial parameters with a gait analysis system. The patients with MS showed improvements in cadence and walking speed when using the insoles. Sagittal plane angles of the hip and knee were increased while using insoles (p<0.05) and ankle plantar flexion was found to be decreased, compared to barefoot walking (p<0.05).

Conclusion

Our study results suggest that insole with arch support affects gait cycle, but does not improve gait impairments in patients with MS. Insoles may ensure plantar sensory feedback in feet during walking, which increases pressure in the mid-forefoot area.

Textured insoles affect the plantar pressure distribution while elite rowers perform on an indoor rowing machine

INTRODUCTION

During rowing, foot positioning on the foot stretcher is critical to optimise muscle force transmission and boat propulsion. Following the beneficial effects of textured insoles on gait and balance, this study aims at investigating whether passive stimulation of foot mechanoreceptors induced by these insoles may contribute to improving foot loading pattern and symmetry during indoor rowing.

METHODS

Eleven elite rowers were assessed during controlled training on a standard rowing machine while wearing control, low-density or high-density textured insoles. Plantar pressure and knee and trunk kinematics were measured; performance data were recorded from the machine. Insole effect on kinematic parameters, peak and average values of foot force, contact area and position of centre of pressure was assessed with ANOVA and Bonferroni correction for pair-wise comparisons.

RESULTS

A main effect was observed for force and contact area, with the high-density insoles providing greatest values (P<0.035). No interaction was observed between side and insole (P>0.190), even though symmetry was higher with high-density insoles. Kinematics (P = 0.800) and rowing performance were not affected by insole type; a consistent though not statistically significant increase in mean travelled distance was observed for denser insoles (P>0.21).

CONCLUSION

The high-density textured insoles affected foot loading distribution during indoor rowing. Rowers applied greater foot force and over a greater foot stretcher area with the high-density than the low-density and control insoles. These findings and the methodology applied may be relevant for the understanding and monitoring of rowing performance.

Foot orthoses for plantar heel pain: a systematic review and meta-analysis

Objective

To investigate the effectiveness of foot orthoses for pain and function in adults with plantar heel pain.

Design

Systematic review and meta-analysis. The primary outcome was pain or function categorised by duration of follow-up as short (0 to 6 weeks), medium (7 to 12 weeks) or longer term (13 to 52 weeks).

Data sources

Medline, CINAHL, SPORTDiscus, Embase and the Cochrane Library from inception to June 2017.

Eligibility criteria for selecting studies

Studies must have used a randomised parallel-group design and evaluated foot orthoses for plantar heel pain. At least one outcome measure for pain or function must have been reported.

Results

A total of 19 trials (1660 participants) were included. In the short term, there was very low-quality evidence that foot orthoses do not reduce pain or improve function. In the medium term, there was moderate-quality evidence that foot orthoses were more effective than sham foot orthoses at reducing pain (standardised mean difference −0.27 (−0.48 to −0.06)). There was no improvement in function in the medium term. In the longer term, there was very low-quality evidence that foot orthoses do not reduce pain or improve function. A comparison of customised and prefabricated foot orthoses showed no difference at any time point.

Conclusion

There is moderate-quality evidence that foot orthoses are effective at reducing pain in the medium term, however it is uncertain whether this is a clinically important change.

Effectiveness of foot orthoses and shock-absorbing insoles for the prevention of injury: a systematic review and meta-analysis

OBJECTIVE

To investigate the evidence relating to the effectiveness of foot orthoses and shock-absorbing insoles for the prevention of musculoskeletal injury.

DESIGN

Systematic review and meta-analysis.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Clinical trials evaluating the effectiveness of foot orthoses and shock-absorbing insoles for the prevention of injury.

DATA SOURCES

Cochrane Library, CINAHL, EMBASE, MEDLINE and SPORTDiscus from their inception up to the first week of June 2016.

RESULTS

11 trials that had evaluated foot orthoses and 7 trials that had evaluated shock-absorbing insoles were included. The median Physiotherapy Evidence Database (PEDro) score for trials that had evaluated foot orthoses and shock-absorbing insoles was 5 (range 3-8/10) and 3 (range 1-7/10), respectively. Meta-analysis found that foot orthoses were effective for preventing overall injuries (risk ratio (RR) 0.72, 95% CI 0.55 to 0.94) and stress fractures (RR 0.59, 95% CI 0.45 to 0.76), but not soft-tissue injuries (RR 0.79, 95% CI 0.55 to 1.14). In contrast, shock-absorbing insoles were not effective for preventing overall injuries (RR 0.92, 95% CI 0.73 to 1.16), stress fractures (RR 1.15, 95% CI 0.57 to 2.32) or soft-tissue injuries (RR 0.92, 95% CI 0.74 to 1.15).

CONCLUSIONS

Foot orthoses were found to be effective for preventing overall injuries and stress fractures but not soft-tissue injuries, while shock-absorbing insoles were not found to be effective for preventing any injury. However, further well-designed trials will assist the accuracy and precision of the estimates of risk reduction as the quality of the included trials varied greatly.

Effects of insoles contact on static balance

[Purpose] This study examined the effect of the degree of the contact area between the insoles and soles on static balance. [Subjects and Methods] Thirteen healthy male and female adults voluntarily participated. All of the subjects wore three different types of insoles (no orthotic insole, partial contact, full contact) in the present experiment. The subjects were instructed to place both feet parallel to each other and maintain static balance for 30 seconds. Center of pressure parameters (range, total distance, and mean velocity) were analyzed. [Results] The results show that the anteroposterior range and mediolateral (ML) total distance and velocity decreased when orthotic insoles with partial contact or full contact were used in comparison to when a flat insole (no orthotic insole) was used. Also, the ML range and total distance were lower with full contact than in the other two conditions. These results indicate that static balance improves as the degree of contact between the soles and insoles increases. [Conclusion] The results of this study suggests that using insoles with increased sole contact area would improve static balance ability.

The feasibility of a modified shoe for multi-segment foot motion analysis: a preliminary study

Background

The majority of multi-segment kinematic foot studies have been limited to barefoot conditions, because shod conditions have the potential for confounding surface-mounted markers. The aim of this study was to investigate whether a shoe modified with a webbed upper can accommodate multi-segment foot marker sets without compromising kinematic measurements under barefoot and shod conditions.

Methods

Thirty participants (15 controls and 15 participants with midfoot pain) underwent gait analysis in two conditions; barefoot and wearing a shoe (shod) in a random order. The shod condition employed a modified shoe (rubber plimsoll) with a webbed upper, allowing skin mounted reflective markers to be visualised through slits in the webbed material. Three dimensional foot kinematics were captured using the Oxford multi-segment foot model whilst participants walked at a self-selected speed.

Results

The foot pain group showed greater hindfoot eversion and less hindfoot dorsiflexion than controls in the barefoot condition and these differences were maintained when measured in the shod condition. Differences between the foot pain and control participants were also observed for walking speed in the barefoot and in the shod conditions. No significant differences between foot pain and control groups were demonstrated at the forefoot in either condition.

Conclusions

Subtle differences between pain and control groups, which were found during barefoot walking are retained when wearing the modified shoe. The novel properties of the modified shoe offers a potential solution for the use of passive infrared based motion analysis for shod applications, for instance to investigate the kinematic effect of foot orthoses.

Predicting Dynamic Foot Function From Static Foot Posture: Comparison Between Visual Assessment, Motion Analysis, and a Commercially Available Depth Camera

STUDY DESIGN :Controlled laboratory study.

OBJECTIVE

To evaluate the ability of 3 methods to assess static foot posture to predict rearfoot and midfoot kinematics during gait.

BACKGROUND

Static foot posture is commonly used clinically to infer dynamic function. Limitations of static clinical assessments may be overcome through advances in technologies, including commercially available depth cameras.

METHODS

The Foot Posture Index (FPI) of 31 males (average age, 22.5 years) was assessed using visual observation, a 3-D motion-analysis system, and a depth camera. Pearson correlations were used to evaluate relationships between FPI items and rearfoot and midfoot kinematics during walking. The ability of the static variables to predict dynamic function was assessed using multiple linear regression.

RESULTS

Most FPI items (85%) were not correlated with foot kinematics, regardless of assessment method. There were 6 fair to moderate correlations between visual FPI items and total rearfoot (r = -0.36 to -0.39, P<.05) and midfoot (r = 0.37 to 0.61, P<.05) motion, 2 fair correlations between 3-D motion-analysis FPI items and total midfoot (r = -0.43, P = .02) and peak rearfoot (r = -0.40, P = .03) motion, and 2 fair correlations between the depth-camera FPI items and average rearfoot (r = -0.38 to 0.44, P<.05) motion. Visual assessment of the FPI provided the best prediction model, explaining 37% of the variance in total midfoot inversion/eversion.

CONCLUSION

Static measures of foot posture are weakly correlated with rearfoot or midfoot kinematics, and have limited dynamic prediction ability. Our findings suggest that the FPI may not be an accurate representation of rearfoot or midfoot movement during walking, regardless of the measurement technique employed.

Effects of the site and extent of plantar cutaneous stimulation on dynamic balance and muscle activity while walking

BACKGROUND

Previous studies have demonstrated that stimulating the cutaneous plantar sensory receptors of the foot through textured insoles improves human balance and walking. This study investigated the effect of medial and lateral zoned textured insoles using tibialis anterior/peroneus longus surface electromyographic activity and Centre-of-Pressure as indicators of postural stability while walking.

METHODS

15 asymptomatic subjects were tested using a within-subject randomised repeated measures design. The effect of lateral and medial zoned insoles of varying heights (control, 2, 4 and 6mm) on stability while walking under normal and impaired visual conditions was assessed.

RESULTS

Impaired vision resulted in an increase in foot CoP variability while walking (p<0.05). The laterally zoned insole was associated with a significant (repeated measures ANOVA p<0.05) increase in the rate of medial-lateral CoP change.

CONCLUSION

These findings suggest that the site of stimulation of the plantar foot cutaneous receptors may increase postural instability during walking. This should be considered in the design of insoles that aim to improve balance and reduce falls risk. The importance of vision in balance control has been highlighted and using impaired vision may serve as a way of trialling clinical products in the healthy population.

Musculoskeletal stiffness during hopping and running does not change following downhill backwards walking

Eccentric contractions that provide spring energy can also cause muscle damage. The aim of this study was to explore leg and vertical stiffness following muscle damage induced by an eccentric exercise protocol. Twenty active males completed 60 minutes of backward-walking on a treadmill at 0.67 m/s and a gradient of - 8.5° to induce muscle damage. Tests were performed immediately before; immediately post; and 24, 48, and 168 hours post eccentric exercise. Tests included running at 3.35 m/s and hopping at 2.2 Hz using single- and double-legged actions. Leg and vertical stiffness were measured from kinetic and kinematic data, and electromyography (EMG) of five muscles of the preferred limb were recorded during hopping. Increases in pain scores (over 37%) occurred post-exercise and 24 and 48 hours later (p < 0.001). A 7% decrease in maximal voluntary contraction occurred immediately post-exercise (p = 0.019). Changes in knee kinematics during single-legged hopping were observed 168 hours post (p < 0.05). No significant changes were observed in EMG, creatine kinase activity, leg, or vertical stiffness. Results indicate that knee mechanics may be altered to maintain consistent levels of leg and vertical stiffness when eccentric exercise-induced muscle damage is present in the lower legs.

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.

Changes in windlass effect in response to different shoe and insole designs during walking

Windlass effect occurs during the pre-swing phase of gait cycle in which the peak tensile strain and force of the plantar aponeurosis (PA) is reached. The increased dorsiflexion angle of the 1st metatarsophalangeal (MTP) joint is the main causing factor. The aim of this study was to investigate thoroughly in finding the appropriate shoe and insole combination that can effectively decrease the windlass effect. Foot kinematic analyses of 10 normal volunteers (aged 25.2±2.1 years, height of 167.4±9.1 cm, and weight of 66.2±18.1 kg) were performed during gait under the conditions of barefoot, standard shoe (SS) with flat insole (FI) or carbon fiber insole (CFI), and rocker sole shoe (RSS) with FI or CFI. The shoe cover consisting of transparent polymer was used for accurate measurement of kinematic data as specific areas on the cover can be cut away for direct placement of reflective markers onto the skin. Under barefoot condition, the mean of maximum dorsiflexion angle of the 1st MTP joint was measured to be 48.0±7.3°, and decreased significantly to 28.2±5.7° when wearing SS with FI, and 24.1±5.7° when wearing SS with CFI. This angle was further decreased to around 13° when wearing RSS with FI or CFI. Subjects wearing footwear alone can increase the minimum medial longitudinal angle and decrease the maximum plantarflexion angle of metatarsus related to the calcaneus as compared with barefoot condition, resulting in flatter medial foot arch. Results suggested that RSS is the effective footwear in reducing the windlass effect regardless the type of insole inserted. The findings in this study provided us with the evidences in finding the appropriate footwear for treating foot disorders such as plantar fasciitis by effectively reducing the windlass effect.