Foot callus thickness does not trade off protection for tactile sensitivity during walking.

Until relatively recently, humans, similar to other animals, were habitually barefoot. Therefore, the soles of our feet were the only direct contact between the body and the ground when walking. There is indirect evidence that footwear such as sandals and moccasins were first invented within the past 40 thousand years1, the oldest recovered footwear dates to eight thousand years ago2 and inexpensive shoes with cushioned heels were not developed until the Industrial Revolution3. Because calluses-thickened and hardened areas of the epidermal layer of the skin-are the evolutionary solution to protecting the foot, we wondered whether they differ from shoes in maintaining tactile sensitivity during walking, especially at initial foot contact, to improve safety on surfaces that can be slippery, abrasive or otherwise injurious or uncomfortable. Here we show that, as expected, people from Kenya and the United States who frequently walk barefoot have thicker and harder calluses than those who typically use footwear. However, in contrast to shoes, callus thickness does not trade-off protection, measured as hardness and stiffness, for the ability to perceive tactile stimuli at frequencies experienced during walking. Additionally, unlike cushioned footwear, callus thickness does not affect how hard the feet strike the ground during walking, as indicated by impact forces. Along with providing protection and comfort at the cost of tactile sensitivity, cushioned footwear also lowers rates of loading at impact but increases force impulses, with unknown effects on the skeleton that merit future study.

Associations between static foot posture, dynamic in-shoe plantar foot forces and knee pain in people with medial knee osteoarthritis: A cross-sectional exploratory study.

OBJECTIVE: To investigate relationships between static foot posture, dynamic plantar foot forces and knee pain in people with medial knee osteoarthritis (OA). DESIGN: Data from 164 participants with symptomatic, moderate to severe radiographic medial knee OA were analysed. Knee pain was self-reported using a numerical rating scale (NRS; scores 0-10; higher scores worse) and the Knee Injury and Osteoarthritis Outcome Score pain subscale (KOOS; scores 0-100; lower scores worse). Static foot posture was assessed using clinical tests (foot posture index, foot mobility magnitude, navicular drop). Dynamic plantar foot forces (lateral, medial, whole foot, medial-lateral ratio, arch index) were measured using an in-shoe plantar pressure system while walking. Relationships between foot posture and plantar forces (independent variables) and pain (dependent variables) were evaluated using linear regression models, unadjusted and adjusted for sex, walking speed, Kellgren & Lawrence grade, shoe category, and body mass (for dynamic plantar foot forces). RESULTS: No measure of static foot posture was associated with any knee pain measure. Higher medial-lateral foot force ratio at midstance, and a higher arch index during overall stance, were weakly associated with higher knee pain on the NRS (regression coefficient = 0.69, 95% confidence interval (CI) 0.09 to 1.28) and KOOS (coefficient=3.03, 95% CI 0.71 to 5.35) pain scales, respectively. CONCLUSION: Dynamic plantar foot forces, but not static foot posture, were associated with knee pain in people with medial knee OA. However, the amount of pain explained by increases in plantar foot force was small; thus, these associations are unlikely to be clinically meaningful.

Use, tolerability, benefits and side effects of orthotic devices in Charcot-Marie-Tooth disease.

BACKGROUND: Shoe inserts, orthopaedic shoes, ankle-foot orthoses (AFOs) are important devices in Charcot-Marie-Tooth disease (CMT) management, but data about use, benefits and tolerance are scanty. METHODS: We administered to Italian CMT Registry patients an online ad hoc questionnaire investigating use, complications and perceived benefit/tolerability/emotional distress of shoe inserts, orthopaedic shoes, AFOs and other orthoses/aids. Patients were also asked to fill in the Quebec User Evaluation of Satisfaction with assistive Technology questionnaire, rating satisfaction with currently used AFO and related services. RESULTS: We analysed answers from 266 CMT patients. Seventy per cent of subjects were prescribed lower limb orthoses, but 19% did not used them. Overall, 39% of subjects wore shoe inserts, 18% orthopaedic shoes and 23% AFOs. Frequency of abandonment was high: 24% for shoe inserts, 28% for orthopaedic shoes and 31% for AFOs. Complications were reported by 59% of patients and were more frequently related to AFOs (69%). AFO users experienced greater emotional distress and reduced tolerability as compared with shoe inserts (p<0.001) and orthopaedic shoes (p=0.003 and p=0.045, respectively). Disease severity, degree of foot weakness, customisation and timing for customisation were determinant factors in AFOs' tolerability. Quality of professional and follow-up services were perceived issues. CONCLUSIONS: The majority of CMT patients is prescribed shoe inserts, orthopaedic shoes and/or AFOs. Although perceived benefits and tolerability are rather good, there is a high rate of complications, potentially inappropriate prescriptions and considerable emotional distress, which reduce the use of AFOs. A rational, patient-oriented and multidisciplinary approach to orthoses prescription must be encouraged.

Offloading and adherence through technological advancements: Modern approaches for better foot care in diabetes.

OBJECTIVE: This manuscript aims to provide a review and synthesis of contemporary advancements in footwear, sensor technology for remote monitoring, and digital health, with a focus on improving offloading and measuring and enhancing adherence to offloading in diabetic foot care. METHODS: A narrative literature review was conducted by sourcing peer-reviewed articles, clinical studies, and technological innovations. This paper includes a review of various strategies, from specifically designed footwear, smart insoles and boots to using digital health interventions, which aim to offload plantar pressure and help prevent and manage wounds more effectively by improving the adherence to such offloading. RESULTS: In-house specially made footwear, sensor technologies remotely measuring pressure and weight-bearing activity, exemplified for example, through applications like smart insoles and SmartBoot, and other digital health technologies, show promise in improving offloading and changing patient behaviour towards improving adherence to offloading and facilitating personalised care. This paper introduces the concept of gamification and emotive visual indicators as novel methods to enhance patient engagement. It further discusses the transformative role of digital health technologies in the modern era. CONCLUSIONS: The integration of technology with footwear and offloading devices offers unparallelled opportunities for improving diabetic foot disease management not only through better offloading but also through improved adherence to offloading. These advancements allow healthcare providers to personalise treatment plans more effectively, thereby promising a major improvement in patient outcomes in diabetic foot ulcer healing and prevention.

Height-Resolved Analysis of Indoor Airborne Microbiome: Comparison with Floor Dust-Borne Microbiome and the Significance of Shoe Sole Dust.

Exposure to the indoor airborne microbiome is closely related to the air that individuals breathe. However, the floor dust-borne microbiome is commonly used as a proxy for indoor airborne microbiome, and the spatial distribution of indoor airborne microbiome is less well understood. This study aimed to characterize indoor airborne microorganisms at varying heights and compare them with those in floor dust. An assembly of three horizontally and three vertically positioned Petri dishes coated with mineral oil was applied for passive air sampling continuously at three heights without interruption. The airborne microbiomes at the three different heights showed slight stratification and differed significantly from those found in the floor dust. Based on the apportionment results from the fast expectation-maximization algorithm (FEAST), shoe sole dust contributed approximately 4% to indoor airborne bacteria and 14% to airborne fungi, a contribution that is comparable to that from the floor dust-borne microbiome. The results indicated that floor dust may not be a reliable proxy for indoor airborne microbiome. Moreover, the study highlights the need for height-resolved studies of indoor airborne microbiomes among humans in different activity modes and life states. Additionally, shoe sole-dust-associated microorganisms could potentially be a source to "re-wild" the indoor microbiota.

Evaluating combustion kinetics and quantifying fuel-N conversion tendency of shoe manufacturing waste.

Combustion is an effective and cost-efficient thermochemical conversion method for solid waste, showing promise for the resource utilization of shoe manufacturing waste (SMW). However, SMW is generally composed of different components, which can lead to unstable combustion and excessive pollutant emissions, especially NOx. To date, combustion characteristics, reaction mechanism and fuel nitrogen (fuel-N) conversion of different SMW components remain unclear. In this work, the combustion behavior of typical SMW components combustion was investigated using Thermogravimetric coupled with Fourier transform infrared spectrum (TG-FTIR). A simplified single-step reaction mechanism was proposed according to the temperature interval to estimate reaction mechanism of SMW. Additionally, the relationship between fuel-N conversion tendency and fuel properties was established. The results indicate that the values for the comprehensive combustion performance index (S) and flammability index (C) range from 1.65 to 0.44 and 3.98 to 1.37, respectively. This demonstrates the significant variability in combustion behavior among different SMW components. Cardboard, leather and sponge have higher values of S and C, suggesting a better ignition characteristic and a stable combustion process. During the combustion of SMW, nitrogen oxides (NO and N2O) are the main nitrogen-containing compounds in the flue gases, with NO being the major contributor, accounting for over 82.97 % of the nitrogen oxides. NO has a negative correlation with nitrogen content, but it is opposite for N2O, HCN and NH3. Furthermore, the conversion of NO, N2O and NH3 is proportional to logarithmic values of O/N, while its conversion to HCN is proportional to logarithmic values of VM/N. These findings facilitate the prediction of the fuel-N conversion of solid waste combustion. This work might shed light on combustion optimization and in-situ pollutant emission control in solid waste combustion.

Non-surgical interventions for treating osteoarthritis of the big toe joint.

BACKGROUND: Osteoarthritis (OA) affecting the first metatarsophalangeal joint (hallux rigidus) is common and painful. Several non-surgical treatments have been proposed; however, few have been adequately evaluated. Since the original 2010 review, several studies have been published necessitating this update. OBJECTIVES: To determine the benefits and harms of non-surgical treatments for big toe OA. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search was February 2023. SELECTION CRITERIA: We included randomised trials that compared any type of non-surgical treatment versus placebo (or sham), no treatment (such as wait-and-see) or other treatment. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. The major outcomes were pain, function, quality of life, radiographic joint structure, adverse events and withdrawals due to adverse events. The primary time point was 12 weeks. We used GRADE to assess the certainty of evidence. MAIN RESULTS: This update includes six trials (547 participants). The mean age of participants ranged from 32 to 62 years. Trial durations ranged from 4 to 52 weeks. Treatments were compared in single trials as follows: arch-contouring foot orthoses versus sham inserts; shoe-stiffening inserts versus sham inserts; intra-articular injection of hyaluronic acid versus saline (placebo) injection; arch-contouring foot orthoses versus rocker-sole footwear; peloid therapy versus paraffin therapy; and sesamoid mobilisation, flexor hallucis longus strengthening and gait training plus physical therapy versus physical therapy alone. Certainty of the evidence was limited by the risk of bias and imprecision. Meta-analysis was not performed due to the heterogeneity of interventions. We reported numerical data for the 12-week time point for the three trials that used a placebo/sham control group. Arch-contouring foot orthoses versus sham inserts One trial (88 participants) showed that arch-contouring foot orthoses probably lead to little or no difference in pain, function, or quality of life compared to sham inserts (moderate certainty). Mean pain (0-10 scale, 0 no pain) with sham inserts was 3.9 points compared to 3.5 points with arch-contouring foot orthoses; a difference of 0.4 points better (95% (CI) 0.5 worse to 1.3 better). Mean function (0-100 scale, 100 best function) with sham inserts was 73.3 points compared to 65.5 points with arch-contouring foot orthoses; a difference of 7.8 points worse (95% CI 17.8 worse to 2.2 better). Mean quality of life (-0.04-100 scale, 100 best score) with sham inserts was 0.8 points compared to 0.8 points with arch-contouring foot orthoses group (95% CI 0.1 worse to 0.1 better). Arch-contouring foot orthoses may show little or no difference in adverse events and withdrawal due to adverse events compared to sham inserts (low certainty). Adverse events (mostly foot pain) were reported in 6 out of 41 people with sham inserts and 4 out of 47 people with arch-contouring foot orthoses (RR 0.58, 95% CI 0.18 to 1.92). Withdrawals due to adverse events were reported in 0 out of 41 people with sham inserts and 1 out of 47 people with arch-contouring foot orthoses (Peto OR 6.58, 95% CI 0.13 to 331). Shoe-stiffening inserts versus sham inserts One trial (100 participants) showed that shoe-stiffening inserts probably lead to little or no difference in pain, function, or quality of life when compared to sham inserts (moderate certainty). Mean pain (0-100 scale, 0 no pain) with sham inserts was 63.8 points compared to 70.1 points with shoe-stiffening inserts; a difference of 6.3 points better (95% CI 0.5 worse to 13.1 better). Mean function (0-100 scale, 100 best function) with sham inserts was 81.0 points compared to 84.9 points with shoe-stiffening inserts; a difference of 3.9 points better (95% CI 3.3 worse to 11.1 better). Mean quality of life (0-100 scale, 100 best score) with sham inserts was 53.2 points compared to 53.3 points with shoe-stiffening inserts; a difference of 0.1 points better (95% CI 3.7 worse to 3.9 better). Shoe-stiffening inserts probably show little or no difference in adverse events (moderate-certainty) and may show little or no difference in withdrawal due to adverse events (low-certainty), compared to sham inserts. Adverse events (mostly foot pain, blisters, and spine/hip pain) were reported in 31 out of 51 people with sham inserts and 29 out of 49 people with shoe-stiffening inserts (RR 0.94, 95% CI 0.42 to 2.08). Withdrawals due to adverse events were reported in 1 out of 51 people with sham inserts and 2 out of 49 people with shoe-stiffening inserts (Peto OR 2.08, 95% CI 0.19 to 22.23). Hyaluronic acid versus placebo One trial (151 participants) showed that a single intra-articular injection of hyaluronic acid probably leads to little or no difference in pain or function compared to placebo (moderate certainty). Mean pain (0-100 scale, 0 no pain) with placebo was 72.5 points compared to 68.2 points with hyaluronic acid; a difference of 4.3 points better (95% CI 2.1 worse to 10.7 better). Mean function (0-100 scale, 100 best function) was 83.4 points with placebo compared to 85.0 points with hyaluronic acid; a difference of 1.6 points better (95% CI 4.6 worse to 7.8 better). Hyaluronic acid may provide little or no difference in quality of life (0-100 scale, 100 best score) which was 79.9 points with placebo compared to 82.9 points with hyaluronic acid; a difference of 3.0 better (95% CI 1.4 worse to 7.4 better; low certainty). There may be fewer adverse events with hyaluronic acid compared to placebo. Adverse events (mostly pain at the injection site) were reported in 43 out of 76 people with placebo compared with 27 out of 75 people with hyaluronic acid (RR 0.64, 95% CI 0.44 to 0.91; low certainty). No participants withdrew from either group due to adverse events. The effects on radiographic joint structure were not reported in any study. AUTHORS' CONCLUSIONS: The existing evidence regarding the benefits and harms of non-surgical treatments for big toe OA is limited. There is moderate-certainty evidence, based upon three single placebo/sham-controlled trials, that there are no clinically important benefits of arch-contouring foot orthoses, shoe-stiffening inserts, or a single intra-articular injection of hyaluronic acid. Further placebo-controlled trials are needed to evaluate the effectiveness of non-surgical treatments for big toe OA.

Footwear, Orthoses, and Insoles and Their Effects on Balance in Older Adults: A Scoping Review.

BACKGROUND: Footwear, orthoses, and insoles have been shown to influence balance in older adults; however, it remains unclear which features, singular or in combination, are considered optimal. The aim of this scoping review was to identify and synthesise the current evidence regarding how footwear, orthoses, and insoles influence balance in older adults. Four electronic databases (MEDLINE, CINAHL, Embase, and AMED) were searched from inception to October 2023. Key terms such as "shoe*," "orthoses," "postural balance" and "older people" were employed in the search strategy. Studies meeting the following criteria were included: (i) participants had a minimum age ≥60 years, and were free of any neurological, musculoskeletal, and cardiovascular diseases; (ii) an active intervention consisting of footwear, foot orthoses, or insoles was evaluated; and (iii) at least one objective outcome measure of balance was reported. SUMMARY: A total of 56 studies from 17 different countries were included. Three study designs were utilised (cross-sectional study, n = 44; randomised parallel group, n = 6; cohort study n = 6). The duration of studies varied considerably, with 41 studies evaluating immediate effects, 14 evaluating effects from 3 days to 12 weeks, and 1 study having a duration of 6 months. Seventeen different interventions were evaluated, including/consisting of textured insoles (n = 12), heel elevation (n = 8), non-specific standardised footwear and changes in sole thickness or hardness (n = 7 each), sole geometry or rocker soles, contoured or custom insoles and high collar height (n = 6 each), insole thickness or hardness and vibrating insoles (n = 5 each), outsole tread (n = 4), minimalist footwear and slippers (n = 3 each), balance-enhancing shoes, footwear fit, socks, and ankle-foot orthoses (n = 2 each), and eversion insoles, heel cups, and unstable footwear (n = 1 each). Twenty-three different outcomes were assessed, and postural sway was the most common (n = 20), followed by temporo-spatial gait parameters (n = 17). There was uncertainty regarding intervention effectiveness. Overall, features such as secure fixation, a textured insole, a medium-to-hard density midsole and a higher ankle collar, in isolation, were able to positively impact balance. Conversely, footwear with an elevated heel height and the use of socks and slippers impaired balance. KEY MESSAGES: There is a substantial body of literature exploring the effects of footwear, orthoses, and insoles on balance in older adults. However, considerable uncertainty exists regarding the efficacy of these interventions due to variability in methodological approaches. Further high-quality research is necessary to determine whether a singular intervention or a combination of interventions is most effective for enhancing balance in older adults.

Footwear and Falls in Long-Term Residential Aged Care Facilities: An Analysis of Video Capture Data.

INTRODUCTION: Several footwear characteristics have been shown to affect balance and gait patterns and may therefore influence the risk of falling in older adults. However, attributing a link between footwear and falls is inherently difficult as it often relies on self-report which may be inaccurate. METHODS: Archival video recordings of falls that occurred in two long-term residential aged care facilities were initially screened to determine whether the footwear worn at the time (barefoot, socks, slippers/sandals, or shoes) could be documented. These falls were then independently evaluated by three additional assessors and a meeting was held to obtain consensus in relation to whether the footwear could have potentially contributed to the fall, and what mechanism may have been responsible. Cross-tabulations were performed in relation to footwear type and fall characteristics (proposed mechanism and fall direction). RESULTS: There were 300 falls experienced by 118 older adults aged 58 years-98 years (mean age 82.8 years, SD 7.6). Of these falls, footwear could be ascertained in 224 (75%). After the consensus meeting, the proportion of falls considered to be potentially related to footwear was 40 (18%). The likelihood of footwear contributing to the fall was highest when participants were wearing socks (14/19 falls; 74% of all footwear-related falls), followed by being barefoot (2/6 falls; 33%), wearing slippers/sandals (17/100 falls; 17%), and wearing shoes (7/99 falls, 7%). CONCLUSION: Footwear could be a potential contributor to a substantial number of falls in residential aged care. Wearing socks would appear to place an older person at risk of future falls and should therefore be avoided in this population.

Assessing the Acceptability and Effectiveness of a Novel Therapeutic Footwear in Reducing Foot Pain and Improving Function among Older Adults: A Crossover Randomized Controlled Trial.

INTRODUCTION: Nearly, a quarter of older adults suffer from frequent foot pain, impacting their quality of life. While proper footwear can alleviate this, design issues often hinder regular use. This study evaluated novel therapeutic footwear, designed for aesthetics and custom fit, to reduce foot pain. We hypothesized that older adults would experience less foot pain and favor the new footwear over their own. METHODS: This 12-week crossover randomized controlled trial evaluated the effectiveness of OrthoFeet therapeutic footwear on reducing foot pain in older adults (n = 50, age = 65 ± 5, 18% male) with moderate to severe pain. Participants were assigned to either the AB or BA sequence. In AB, they wore OrthoFeet shoes for 6 weeks and then their own shoes for another 6 weeks; BA followed the reverse order. Pain and function were measured using the Foot Function Index. Acceptability was assessed through a technology acceptance model (TAM) questionnaire. Data collected at baseline, six, and 12 weeks were analyzed using t tests, χ2 tests, and generalized linear model. RESULTS: Compared to participants' own shoes, OrthoFeet shoes significantly reduced foot pain and disability. Notable improvements were observed in "foot pain at its worst," "foot pain at the end of the day," "overall pain score," and "overall Foot Function Index score," all showing statistically significant reductions (p < 0.050). Participants reported high adherence to wearing the OrthoFeet shoes, averaging 8 h per day and 5.8 days per week. TAM scores favored OrthoFeet shoes over participants' own shoes in terms of ease of use, perceived benefit, and intention to recommend. Significant differences were noted in components representing perceived joint pain relief (p < 0.001, χ2 = 21.228) and the intention of use as determined by the likelihood of recommending the shoes to a friend with a similar condition (p < 0.001, χ2 = 29.465). Additionally, a majority of participants valued the appearance of the shoes, with 66% prioritizing shoe appearance and 96% finding the study shoes more stylish than their previous ones. CONCLUSION: This study underscores the significance of design and custom fit in promoting continuous wear for effective foot pain reduction in older adults. More research is needed on the intervention's long-term impacts.

Foot Problems in Older Adults Presenting to a Falls and Balance Clinic.

INTRODUCTION: Foot problems, including musculoskeletal problems, peripheral neuropathy, peripheral arterial disease and dermatologic pathology are common in older adults and are associated with an increased risk of falling. Multicomponent podiatry interventions have been shown to reduce the incidence of falls. This paper aimed to identify older adults requiring podiatry input in a Falls and Balance clinic; to describe the model of foot health care they receive; to explore cross-sectional associations between foot problems and function and ultimately demonstrate the role of podiatry input in the multidisciplinary management of falls risk. METHODS: Cohort study of patients attending a Falls and Balance Clinic for Comprehensive Geriatric Assessment. Demographic information was collected and functional independence, mobility, foot problems, and footwear were assessed in the clinic. RESULTS: One-hundred and two patients were included; median age 79.3 (73-84.3) years, 68.6% female, 93.1% residing independently, 62.7% used a gait aid. Podiatry referrals were made in 80.4% of cases, with muscle weakness being the most common problem identified (90.2%); 74.8% were found to be wearing inappropriate footwear. Most patients received footwear education and half were prescribed foot and ankle strengthening exercises. Hallux and lesser toe weakness were associated with lower Short Physical Performance Battery scores (p < 0.001). CONCLUSION: The majority of older adults in the Falls and Balance Clinic required podiatry input, with foot weakness and inappropriate footwear being common reasons for referral. Those with weakness of the hallux and lesser toes had poorer balance and mobility, which is known to be associated with greater falls risk. This highlights the need for podiatry assessment and interventions as part of the multidisciplinary approach to the management of falls risk in older adults.

Influence of different midsole foam in advanced footwear technology use on running economy and biomechanics in trained runners.

BACKGROUND: Ethylene and vinyl acetate (EVA) and polyether block amide (PEBA) are recently the most widely used materials for advanced footwear technology (AFT) that has been shown to improve running economy (RE). This study investigated the effects of these midsole materials on RE and biomechanics, in both fresh and worn state (after 450 km). METHODS: Twenty-two male trained runners participated in this study. Subjects ran four 4-min trials at 13 km‧h-1 with both fresh EVA and PEBA AFT and with the same models with 450 km of wear using a randomized crossover experimental design. We measured energy cost of running (W/kg), spatiotemporal, and neuromuscular parameters. RESULTS: There were significant differences in RE between conditions (p = 0.01; n2 = 0.17). There was a significant increase in energy cost in the worn PEBA condition compared with new (15.21 ± 1.01 and 14.87 ± 0.99 W/kg; p < 0.05; ES = 0.54), without differences between worn EVA (15.13 ± 1.14 W/kg; p > 0.05), and new EVA (15.15 ± 1.13 w/kg; ES = 0.02). The increase in energy cost between new and worn was significantly higher for the PEBA shoes (0.32 ± 0.38 W/kg) but without significant increase for the EVA shoes (0.06 ± 0.58 W/kg) (p < 0.01; ES = 0.51) with changes in step frequency and step length. The new PEBA shoes had lower energy cost than the new EVA shoes (p < 0.05; ES = 0.27) with significant differences between conditions in contact time. CONCLUSION: There is a clear RE advantage of incorporating PEBA versus EVA in an AFT when the models are new. However, after 450 km of use, the PEBA and EVA shoes had similar RE.

Changes in running economy and running technique following 6 months of running with and without wearable-based real-time feedback.

BACKGROUND: An increasing number of commercially available wearables provide real-time feedback on running biomechanics with the aim to reduce injury risk or improve performance. OBJECTIVE: Investigate whether real-time feedback by wearable insoles (ARION) alters running biomechanics and improves running economy more as compared to unsupervised running training. We also explored the correlation between changes in running biomechanics and running economy. METHODS: Forty recreational runners were randomized to an intervention and control group and performed ~6 months of in-field training with or without wearable-based real-time feedback on running technique and speed. Running economy and running biomechanics were measured in lab conditions without feedback pre and post intervention at four speeds. RESULTS: Twenty-two individuals (13 control, 9 intervention) completed both tests. Both groups significantly reduced their energetic cost by an average of -6.1% and -7.7% for the control and intervention groups, respectively. The reduction in energy cost did not significantly differ between groups overall (-0.07 ± 0.14 J∙kg∙m-1 , -1.5%, p = 0.63). There were significant changes in spatiotemporal metrics, but their magnitude was minor and did not differ between the groups. There were no significant changes in running kinematics within or between groups. However, alterations in running biomechanics beyond typical session-to-session variation were observed during some in-field sessions for individuals that received real-time feedback. CONCLUSION: Alterations in running biomechanics as observed during some in-field sessions for individuals receiving wearable-based real-time feedback did not result in significant differences in running economy or running biomechanics when measured in controlled lab conditions without feedback.

Effects of a 12-week gait retraining program on the Achilles tendon adaptation of habitually shod runners.

PURPOSE: This study investigated the effects of a 12-week gait retraining program on the morphological and mechanical properties of the Achilles tendon (AT) during running on the basis of real-time dynamic ultrasound imaging. METHODS: A total of 30 male recreational runners who were used to wearing cushioned shoes with a rearfoot strike (RFS) pattern were recruited. They were randomized into a retraining group (RG, n = 15) and a control group (CG, n = 15). The RG group was asked to run in five-fingered minimalist shoes with a forefoot strike (FFS) pattern, and the CG group was asked to keep their strike pattern. Three training sessions were performed per week. All the participants in RG uploaded running tracks obtained through a mobile application (.jpg) after each session for training supervision. The ground reaction force, kinematics, and kinetics of the ankle joint at 10 km/h were collected using an instrumented split-belt treadmill and a motion capture system. The morphological (length and cross-sectional area) and mechanical characteristics (force, stress, strain, etc.) of AT in vivo were recorded and calculated with a synchronous ultrasonic imaging instrument before and after the intervention. Repeated two-way ANOVA was used to compare the aforementioned parameters. RESULTS: A total of 28 participants completed the training. The strike angle of RG after training was significantly smaller than that before training and significantly smaller than that of CG after training (F (1, 13) = 23.068, p < 0.001, partial η2 = 0.640). The length (F (1, 13) = 10.086, p = 0.007, partial η2 = 0.437) and CSA (F (1, 13) = 7.475, p = 0.017, partial η2 = 0.365) of AT in RG increased after training. A significant main effect for time was observed for the time-to-peak AT force (F (1, 13) = 5.225, p = 0.040, partial η2 = 0.287), average (F (1, 13) = 7.228, p = 0.019, partial η2 = 0.357), and peak AT loading rate (F (1, 13) = 11.687, p = 0.005, partial η2 = 0.473). CONCLUSION: Preliminary evidence indicated that a 12-week gait retraining program could exert a beneficial effect on AT. 57% (8/14) runners in RG shifted from RFS to FFS pattern. Although not all runners were categorized as FFS pattern after the intervention, their foot strike angle was reduced. Retraining primarily positively promoted AT morphological properties (i.e., CSA and length) to strengthen AT capability for mechanical loading.

Relationship Between Advanced Footwear Technology Longitudinal Bending Stiffness and Energy Cost of Running.

INTRODUCTION/PURPOSE: Shoe longitudinal bending stiffness (LBS) is often considered to influence running economy (RE) and thus, running performance. However, previous results are mixed and LBS levels have not been studied in advanced footwear technology (AFT). The purpose of this study was to evaluate the effects of increased LBS from curved carbon fiber plates embedded within an AFT midsole compared to a traditional running shoe on RE and spatiotemporal parameters. METHODS: Twenty-one male trained runners completed three times 4 min at 13 km/h with two experimental shoe models with a curved carbon fiber plate embedded in an AFT midsole with different LBS values (Stiff: 35.5 N/mm and Stiffest: 43.1 N/mm), and a Control condition (no carbon fiber plate: 20.1 N/mm). We measured energy cost of running (W/kg) and spatiotemporal parameters in one visit. RESULTS: RE improved for the Stiff shoe condition (15.71 ± 0.95 W/kg; p < 0.001; n2 = 0.374) compared to the Control condition (16.13 ± 1.08 W/kg; 2.56%) and Stiffest condition (16.03 ± 1.19 W/kg; 1.98%). However, we found no significant differences between the Stiffest and Control conditions. Moreover, there were no spatiotemporal differences between shoe conditions. CONCLUSION: Changes in LBS in AFT influences RE suggesting that moderately stiff shoes have the most effective LBS to improve RE in AFT compared to very stiff shoes and traditional, flexible shoe conditions while running at 13 km/h.

Effects of gait retraining using minimalist shoes on the medial gastrocnemius muscle-tendon unit behavior and dynamics during running.

The effects of a 12-week gait retraining program on the adaptation of the medial gastrocnemius (MG) and muscle-tendon unit (MTU) were investigated. 26 runners with a rearfoot strike pattern (RFS) were randomly assigned to one of two groups: gait retraining (GR) or control group (CON). MG ultrasound images, marker positions, and ground reaction forces (GRF) were collected twice during 9 km/h of treadmill running before and after the intervention. Ankle kinetics and the MG and MTU behavior and dynamics were quantified. Runners in the GR performed gradual 12-week gait retraining transitioning to a forefoot strike pattern. After 12-week, (1) ten participants in each group completed the training; eight participants in GR transitioned to non-RFS with reduced foot strike angles; (2) MG fascicle contraction length and velocity significantly decreased after the intervention for both groups, whereas MG forces increased after intervention for both groups; (3) significant increases in MTU stretching length for GR and peak MTU recoiling velocity for both groups were observed after the intervention, respectively; (4) no significant difference was found for all parameters of the series elastic element. Gait retraining might potentially influence the MG to operate at lower fascicle contraction lengths and velocities and produce greater peak forces. The gait retraining had no effect on SEE behavior and dynamics but did impact MTU, suggesting that the training was insufficient to induce mechanical loading changes on SEE behavior and dynamics.

Soft-Tissue Vibrations and Fatigue During Prolonged Running: Does an Individualized Midsole Hardness Play a Role?

Footwear has the potential to reduce soft-tissue vibrations (STV) but responses are highly subject-specific. Recent evidence shows that compressive garments minimizing STV have a beneficial effect on neuromuscular (NM) fatigue. The aim was to determine whether an individualized midsole hardness can minimize STV and NM fatigue during a half marathon. Twenty experienced runners were recruited for three visits: a familiarization session including the identification of midsole minimizing and maximizing STV amplitude (MIN and MAX, respectively), and two half marathon sessions at 95% of speed at the second ventilatory threshold. STV of the gastrocnemius medialis (GM) muscle, running kinetics, foot strike pattern, rating perceived exhaustion (RPE), and midsole liking were recorded every 3 km. NM fatigue was assessed on plantar flexors (PF) before (PRE) and after (POST) the half marathon. At POST, PF central and peripheral alterations and changes in contact time, step frequency, STV median frequency, and impact force frequency as well as foot strike pattern were found in both MIN and MAX. No significant differences in damping, STV main frequency, flight time, duty factor, and loading rate were observed between conditions whatever the time period. During the half marathon, STV amplitude of GM significantly increased over time for the MAX condition (+13.3%) only. Differences between MIN and MAX were identified for RPE and midsole liking. It could be hypothesized that, while significant, the effect of midsole hardness on STV is too low to substantially affect NM fatigue.

Evaluation of usability, adherence, and clinical efficacy of therapeutic footwear in persons with diabetes at moderate to high risk of diabetic foot ulcers: A multicenter prospective study.

OBJECTIVE: To evaluate therapeutic footwear expectations and usability of individuals with diabetes and foot complications. DESIGN: A prospective multicenter study was conducted on participants with a high risk of developing a diabetic foot ulcer. SETTING: Participants were enrolled in 11 different specialized diabetic foot units in Spain between March 2022 and June 2023. SUBJECTS: Patients with diabetes at moderate to high risk of foot ulceration receiving first therapeutic footwear prescription. INTERVENTIONS: All the patients included in the research were prescribed with their first pair of therapeutic footwear. MAIN MEASURES: Primary outcome measures were MOS-pre and MOS-post questionnaires evaluating use and usability of prescribed therapeutic footwear. Secondary outcome measures aimed to evaluate footwear clinical efficacy as ulceration rate and self-reported perceived walking distance per day. RESULTS: The use of therapeutic footwear exceeded the patient's pre-provision prediction of their anticipated use in 94% of people (n = 126). Based on the visual analogic satisfaction scale, the median satisfaction of daily wearing their therapeutic footwear was 7 points, Interquartile Range (IQR) [5-8.25]. During the follow-up period, 39 participants (29.1%) experienced diabetic foot ulcer. Perceived walking distance participants reported an improvement in their perceived walking ability during various daily life activities. CONCLUSIONS: Diabetes patients at moderate to high risk of diabetic foot ulcer improved their perception of walking ability after therapeutic footwear prescription. Adherence to the therapeutic footwear prescription resulted in less ulcerations.

The effect of advanced footwear technology on elite male marathon race speed.

PURPOSE: The aim of this study was to explore the ergogenic effect of advanced footwear technology (AFT) upon world-class male marathon running speed. METHOD: A retrospective analysis of 99 world-class male marathon runners' performances between 2012 and 2021 was undertaken, providing a sample size of 971 performances, split into two footwear groups: AFT (n = 299) and traditional (n = 672). Additionally, details regarding the year of the marathon performance and racecourse were extracted. A mixed model for repeated measures (MMRM) analysis were undertaken identifying athlete (Wald Z = 2.821; p = .005) and course (Wald Z = 4.111; p < 0.001) as significant contributors to the variance in marathon running speed and as such were included as random factors with footwear type set as a fixed factor. RESULTS: World-class male marathon running speeds were significantly faster (p < 0.001) when running in AFT (5.441 m.s-1) when compared with traditional shoes (5.386 m.s-1) with a mean difference of 0.055 m.s-1 (95% CI 0.039-0.071 m.s-1), translating to an improvement in marathon speed of 1.0% or a 79 s improvement in marathon race time. CONCLUSION: Our findings demonstrate an improvement in world-class male marathon running speed of 1% when running in AFT, a near identical degree of improvement to the male marathon world record ran in AFT. Whilst a 1% improvement in marathon running times associated with AFT is smaller than previously predicted utilizing laboratory-based models, this still reflects a significant degree of improvement at the elite level.