Different Types Of Footwear Research Articles

Design and build of a portable apparatus for measuring lace tension

Laces have traditionally been used to secure the foot, limit slippage, enhance fit, and prevent injury across different types of footwear. Quantitatively assessing the merits and effectiveness of laces is technically challenging due to the lack of portable instrumentation that can measure lace tension reliably. Therefore, the purpose of the study was to design and build a portable apparatus to quantify lace tension to be used on footwear in both laboratory and real-world environments. The apparatus was designed to meet three major design criteria: (i) portable, (ii) able to accommodate different types of footwear, lace materials, and lacing patterns, and (iii) able to measure lace tension while the footwear is secured on the foot. As a result of the design process, the apparatus consisted of a base, fabricated from High Density Polyethylene (HDPE), and a frame, made from aluminum and 3D printed Acrylonitrile Butadiene Styrene (ABS). A measurement system was affixed to the frame and consisted of a lever, a non-deformable cable with a hook, a load cell, a caliper, and a microcontroller to measure the force and change in length of laces when a force was applied. The total height and weight of the apparatus was 25.5 cm and 6.35 kg, respectively. A reliability analysis was conducted using three different types of laces (waxed, non-waxed, and carbon fiber blend) and revealed a high internal consistency within lace types with alpha values of 0.95, 0.81, 0.91, respectively. The interclass reliability coefficient across lace types revealed an alpha value of 0.84. As a result of the design, build, and reliability analysis, the apparatus was able to provide reliable measurements of lace tension while satisfying the design criteria. It is envisioned that the apparatus can be used for ongoing investigations across different types of footwear and different types of laces.

Foot Sole Contact Forces vs. Ground Contact Forces to Obtain Foot Joint Moments for In-Shoe Gait-A Preliminary Study.

In-shoe models are required to extend the clinical application of current multisegment kinetic models of the bare foot to study the effect of foot orthoses. Work to date has only addressed marker placement for reliable kinematic analyses. The purpose of this study is to address the difficulties of recording contact forces with available sensors. Ten participants walked 5 times wearing two different types of footwear by stepping on a pressure platform (ground contact forces) while wearing in-shoe pressure sensors (foot sole contact forces). Pressure data were segmented by considering contact cells' anteroposterior location, and were used to compute 3D moments at foot joints. The mean values and 95% confidence intervals were plotted for each device per shoe condition. The peak values and times of forces and moments were computed per participant and trial under each condition, and were compared using mixed-effect tests. Test-retest reliability was analyzed by means of intraclass correlation coefficients. The curve profiles from both devices were similar, with higher joint moments for the instrumented insoles at the metatarsophalangeal joint (~26%), which were lower at the ankle (~8%) and midtarsal (~15%) joints, although the differences were nonsignificant. Not considering frictional forces resulted in ~20% lower peaks at the ankle moments compared to previous studies, which employed force plates. The device affected both shoe conditions in the same way, which suggests the interchangeability of measuring joint moments with one or the other device. This hypothesis was reinforced by the intraclass correlation coefficients, which were higher for the peak values, although only moderate-to-good. In short, both considered alternatives have drawbacks. Only the instrumented in-soles provided direct information about foot contact forces, but it was incomplete (evidenced by the difference in ankle moments between devices). However, recording ground reaction forces offers the advantage of enabling the consideration of contact friction forces (using force plates in series, or combining a pressure platform and a force plate to estimate friction forces and torque), which are less invasive than instrumented insoles (which may affect subjects' gait).

Effect of Footwear Type on Biomechanical Risk Factors for Knee Osteoarthritis.

Regular walking in different types of footwear may increase the mediolateral shear force, knee adduction moment, or vertical ground-reaction forces that could increase the risk of early development of knee osteoarthritis (OA). To compare kinematic and kinetic parameters that could affect the development of knee OA in 3 footwear conditions. Controlled laboratory study. A total of 40 asymptomatic participants performed walking trials in the laboratory at self-selected walking speeds under barefoot (BF), minimalistic (MF), and neutral (NF) footwear conditions. Knee joint parameters were described using discrete point values, and continuous curves were evaluated using statistical parametric mapping. A 3 × 1 repeated-measures analysis of variance was used to determine the main effect of footwear for both discrete and continuous data. To compare differences between footwear conditions, a post hoc paired t test was used. Discrete point analyses showed a significantly greater knee power in NF compared with MF and BF in the weight absorption phase (P < .001 for both). Statistical parametric mapping analysis indicated a significantly greater knee angle in the sagittal plane at the end of the propulsive phase in BF compared with NF and MF (P = .043). Knee joint moment was significantly greater in the propulsive phase for the sagittal (P = .038) and frontal planes (P = .035) in BF compared with NF and MF and in the absorption phase in the sagittal plane (P = .034) in BF compared with MF and NF. A significant main effect of footwear was found for anteroposterior (propulsion, ↑MF, NF, ↓BF [P = .008]; absorption, ↑BF, MF, ↓NF [P = .001]), mediolateral (propulsion, ↑MF, NF, ↓BF [P = .005]; absorption, ↑NF, MF, ↓BF [P = .044]), and vertical (propulsion, ↑NF, BF, ↓MF [P = .001]; absorption, ↑MF, BF, ↓NF [P < .001]) ground-reaction forces. Knee power showed a significant main effect of footwear (absorption, ↑NF, MF, ↓BF [P = .015]; propulsion, ↑MF, NF, ↓BF [P = .039]). Walking in MF without sufficient accommodation affected kinetic and kinematic parameters and could increase the risk of early development of knee OA.

Analysis of Rejection Data in the Lasting Section of the Footwear Industry

In this project work paper, an attempt is made to provide a fundamental concept on the footwear, history, choice of lasting process, materials, Quality control in lasting, DIP section (Direct injection process), and causes of rejection in the lasting department and DIP section and how to minimize the rejection in the lasting department. In the footwear industry, different types of construction are used to make a complete shoe. This project work is carried out about the rejection rate in the lasting section of “Royal Footwear Ltd”. In this industry, the direct injection lasting process, PU pouring lasting process, and Cemented lasting construction are used to make the complete upper. These constructions are very simple systems of shoe making and very popular, common, and easy systems and enhance the production capacity of other lasting processes. In this research, rejection data of the lasting department is collected and analyzed. And the graphical representation of the data is also visualized. A conclusion is made about the rejection rate of different types of footwear for six months.

Young children's footwear taxonomy: An international Delphi survey of parents, health and footwear industry professionals.

There is little consistency between commercial grade footwear brands for determining shoe sizing, and no universally accepted descriptors of common types or features of footwear. The primary aim of this research was to develop a footwear taxonomy about the agreed types of footwear commonly worn by children under the age of six. Secondary aims were to gain consensus of the common footwear features, when different types of footwear would be commonly worn, common terms for key footwear parts, and how movement at some of these footwear parts should be described. Opinions were collected through a three-round modified Delphi international online survey from parents, health professionals, researchers, and footwear industry professionals. The first survey displayed generic pictures about different footwear types and asked participants to provide a grouping term, when the footwear would be worn (for what type of activity) and any grouping features. The second and third rounds presented consensus and gathered agreement on statements. There were 121 participants who provided detailed feedback to open-ended questions. The final round resulted in consensus and agreement on the names of 14 different footwear types, when they are commonly worn and their common features. Participants also reached consensus and agreement on the terms heel counter to describe the back part of footwear and fixtures as the collective term for features allowing footwear adjustability and fastening. They also agreed on terms to quantify the flexibility at footwear sole (bend or twist) or the heel counter. This first taxonomy of children's footwear represents consensus amongst different stakeholders and is an important step in promoting consistency within footwear research. One shoe does not fit all purposes, and the recommendations from this work help to inform the next steps towards ensuring greater transparency and commonality with footwear recommendations.

The impact of self-lacing technology on foot containment during dynamic cutting

The sport of basketball requires repeated dynamic side-to-side movements that can cause foot sliding and place excessive stress on the athlete. Footwear that provides containment to reduce the motion of the foot relative to the shoe may have performance and injury prevention advantages. Foot containment can vary significantly across different types of footwear due to its dependence on the interaction between the shoe lacing system of the upper and specific design features within the shoe. This study used high-speed stereo radiography to assess the impact of a self-lacing system with three conditions of increasing lace tension compared to a control basketball shoe on foot containment by measuring foot–shoe motion during cutting and jab step activities. Twenty healthy athletes performed dynamic cutting activities in view of a unique stereo radiography system positioned to measure motion of specific foot bones while motion capture and perception data were also collected. By tracking bead positions on the foot and shoe, relative motion of the foot inside the shoe was measured along shoe planes during activity. The self-lacing system showed statistically significant reductions in foot–shoe motion of as much as 75.2% while performing dynamic basketball cuts. Controlling tension with the lacing system provides athletes flexibility in containment to go from a loose fit to a tight fit and reduce in-shoe motion by up to 39.3%. Furthermore, perception data showed athletes had 20.1% greater confidence to perform cutting tasks with increases in lace tension. Reduction of in-shoe foot motion with a self-lacing system is an important consideration in the design of footwear for performance athletes.

A comparison of young children's spatiotemporal gait measures in three common types of footwear with different sole hardness.

It is unknown what the impact of sole hardness is on young children's gait. Yet, this feature is commonly marketed as having differing benefits for young children's walking and development. What are the differences in spatiotemporal measures of gait during walking and running in three common types of young children's footwear with a soft sole, compared to a hard sole? The study used a quasi-experimental design, with the condition order randomised using a Latin square sequence. Forty-seven children were recruited (aged 2-4 years). Participants walked or ran the length of a GAITRite mat in a randomized order in a soft (Shore 48-53) or hard soled (Shore 60-65) sneaker, boot and sandal condition. Linear regression analyses were used to investigate the difference between footwear for the different gait parameters including velocity, cadence, step time, swing percentage, stance percentage, double support time and the toe in/out angle. Children walked with a shorter stride length in the hard-soled sandals compared to the soft- soled sandals (p < 0.05). There were no other differences in spatiotemporal variables in the soft versus hard soled sandals during walking or running (p > 0.05). There were no differences in any spatiotemporal gait variables during walking or running in soft versus hard- soled runners and no differences in walking or running in soft versus hard-soled boots (p > 0.05). There were few differences in spatiotemporal parameters between soft and hard-soled footwear in both walking and running in three different types of footwear. This may be a positive finding for footwear designers and manufacturers, as a harder sole appeared to have limited impact on spatiotemporal gait parameters.

Footwear and Elevated Heel Influence on Barbell Back Squat: A Review.

The back squat is one of the most effective exercises in strengthening the muscles of the lower extremity. Understanding the impact of footwear has on the biomechanics is imperative for maximizing the exercise training potential, preventing injury, and rehabilitating from injury. This review focuses on how different types of footwear affect the full-body kinematics, joint loads, muscle activity, and ground reaction forces in athletes of varying experience performing the weighted back squat. The literature search was conducted using three databases, and fourteen full-text articles were ultimately included in the review. The majority of these studies demonstrated that the choice of footwear directly impacts kinematics and kinetics. Weightlifting shoes were shown to decrease trunk lean and generate more plantarflexion relative to running shoes and barefoot lifting. Elevating the heel through the use of external squat wedges is popular method during rehabilitation and was shown to provide similar effects to weightlifting shoes. Additional research with a broader array of populations, particularly novice and female weightlifters, should be conducted to generalize the research results to nonathlete populations. Further work is also needed to characterize the specific effects of sole stiffness and heel elevation height on squatting mechanics.

Does Footwear Influence Countermovement Jump Parameters Used to Assess Performance in Collegiate Basketball Players?

Background: The countermovement jump (CMJ) is used to monitor short- and long-term changes in neuromuscular performance, where practically relevant alteration may be subtle, requiring detailed and consistent testing protocols to limit error and allow detection of meaningful change. Collegiate basketball players often wear different types of footwear depending upon the training activity, potentially influencing CMJ performance outcomes. Objective: This study evaluated the influence of footwear on key CMJ variables used for routine performance assessments in a cohort of 11 NCAA women’s collegiate basketball players. Method: In a cross-over repeated measures study design, players performed three CMJs in Basketball-, Training-(Trainers), and Olympic Weightlifting (WL) shoes, in a randomized order during one testing session. One-way repeated measures analyses of variance (p ≤ .05) and effect sizes (Cohen’s d) were used to discern differences in CMJ variables among shoe conditions. Results: WL demonstrated greater Eccentric Mean Force (p ≤ .014, d ≥ 0.03) and lower Flight Time:Contraction Time (p ≤ .029, d ≥ 0.31), Jump Height (p ≤ .040, d ≥ 0.32), and Reactive Strength Index-Modified (p ≤ .032, d ≥ 0.40) than both Basketball and Trainers. Additionally, WL exhibited lower Concentric Mean Force (p = .018, d = 0.19), Concentric Mean Power (p = .008, d = 0.29), Eccentric Peak Force (p = .050, d = 0.19), and Flight Time (p = .036, d = 0.31) compared to Trainer. No significant differences and only trivial effects appeared between Basketball and Trainers (p &gt; 0.05, d &lt; 0.1). Conclusion: These findings suggest footwear significantly influences CMJ performance. WL shoes appear to negatively impact CMJ performance; however, Basketball and Trainers appear to exert negligible effects that should allow clinicians and practitioners to feel confident about measurement and data quality when performing short- and long-term CMJ measurements in either Basketball or Trainers.

The Feasibility and Effectiveness of Wearable Sensor Technology in the Management of Elderly Diabetics with Foot Ulcer Remission: A Proof-Of-Concept Pilot Study with Six Cases

Aims: Using specials wearable sensors, we explored changes in gait and balance parameters, over time, in elderly patients at high risk of diabetic foot, wearing different types of footwear. This assessed the relationship between gait and balance changes in elderly diabetic patients and the development of foot ulcers, in a bid to uncover potential benefits of wearable devices in the prognosis and management of the aforementioned complication. Methods: A wearable sensor-based monitoring system was used in middle-elderly patients with diabetes who recently recovered from neuropathic plantar foot ulcers. A total of 6 patients (age range: 55–80 years) were divided into 2 groups: the therapeutic footwear group (n = 3) and the regular footwear (n = 3) group. All subjects were assessed for gait and balance throughout the study period. Walking ability and gait pattern were assessed by allowing participants to walk normally for 1 min at habitual speed. The balance assessment program incorporated the “feet together” standing test and the instrumented modified Clinical Test of Sensory Integration and Balance. Biomechanical information was monitored at least 3 times. Results: We found significant differences in stride length (p < 0.0001), stride velocity (p < 0.0001), and double support (p < 0.0001) between the offloading footwear group (OG) and the regular footwear group on a group × time interaction. The balance test embracing eyes-open condition revealed a significant difference in Hip Sway (p = 0.004), COM Range ML (p = 0.008), and COM Position (p = 0.004) between the 2 groups. Longitudinally, the offloading group exhibited slight improvement in the performance of gait parameters over time. The stride length (odds ratio 3.54, 95% CI 1.34–9.34, p = 0.018) and velocity (odds ratio 3.13, 95% CI 1.19–8.19, p = 0.033) of OG patients increased, converse to the double-support period (odds ratio 6.20, 95% CI 1.97–19.55, p = 0.002), which decreased. Conclusions: Special wearable devices can accurately monitor gait and balance parameters in patients in real time. The finding reveals the feasibility and effectiveness of advanced wearable sensors in the prevention and management of diabetic foot ulcer and provides a solid background for future research. In addition, the development of foot ulcers in elderly diabetic patients may be associated with changes in gait parameters and the nature of footwear. Even so, larger follow-up studies are needed to validate our findings.

There is a difference in functional ankle stability between different types of footwear in male athletes: A cross-sectional study

ContextLateral ankle sprains (LAS) are among the most common injuries in sports, with a poor long – term prognosis due to high chronicity and recurrence rates. Chronic ankle instability (CAI) results up to 40% of people that endured a first – time LAS. ObjectiveThe aim of this study was to compare ankle stability between groups characterised by the use of different types of footwear during their sport activities. DesignCross-sectional study. SettingFirm training surface, local sport clubs. ParticipantsFifty - one male subjects were recruited, distributed in four groups based on the type of footwear they use during their sport activities. Main outcome measuresAll subjects performed four clinical ankle stability tests, and completed the Dutch version of the Cumberland Ankle Instability Tool (CAIT) and Profile of Mood States (POMS). All clinical ankle stability tests were performed barefoot. ResultsSubjects performing their sport activities barefoot scored better than subjects performing their sport with shoes at the multiple hop test (p=.002 to .047) and executed the figure–of–8 hop test significantly faster than subjects with submalleolar ankle support (AS) (p=.019). Subjects with submalleolar AS and studs showed significantly better results than subjects with supramalleolar AS on the CAIT– score (p=.024, p=.030) and the side– hop test (p=.050, p=.045). They also scored significantly better than subjects with submalleolar AS for the side – hop test (p=.032), foot – lift test (p=.019) and figure–of 8 hop test (p=.011). ConclusionBarefoot sports performing subjects appear to have better ankle stability compared to subjects performing their sports with shoe support. Subjects performing sports with high AS appear to have worst ankle stability. Level of evidence: Level III, Cross–sectional study.

Aplicación de la Carta C en una Empresa del sector Calzado

La necesidad del calzado ha estado presente desde el inicio de la historia y ha venido creciendo día a día. Su principal función es proteger los pies y evitar que estos se lastimen. Aunque existen diferentes culturas que no necesitan en sus actividades la utilización de ellos, como las culturas occidentales que etiquetan el andar descalzo como falta de ingreso económico. Sin embargo, está claro que para el resto del mundo el calzado es indispensable, básico y necesario. El Sector del calzado en Colombia, está conformado por las empresas que fabrican, importan, comercializan y exportan, los diferentes tipos de calzado, entre los que se destaca el calzado deportivo, con una participación cercana al 40% del total de la producción nacional. La demanda de calzado en Colombia, al igual que en el resto del mundo está fuertemente influenciada por las tendencias de la moda y el precio. Teniendo en cuenta lo anterior, se escogió una pequeña empresa dedicada a la fabricación de calzado de hombre y dama, el producto al cual se le realizó el estudio fue el deportivo-Hombre, que en la actualidad es el producto de mayor rotación en la empresa. Con la ayuda de herramientas de control de calidad como la aplicación del Diagrama de Ishikawa, se pudo observar y analizar de manera minuciosa las causas principales que generan en el proceso de fabricación los productos defectuosos, a su vez, mediante los gráficos de control C, se evidenció la estabilidad del proceso, es decir, que se encuentra bajo de control estadístico.

Thermal Equations for Predicting Foot Skin Temperatur

Purpose: Studying the foot skin temperature of both the young and elderly is important for preventing foot diseases and improving thermal comfort and variability during gait. However, few studies have predicted the thermal conditions in footwear under different variables. The aim of this study is to therefore formulate thermal equations for both the young and elderly to predict their foot skin temperature under the variables of age, gender, activity level and various properties of different types of footwear.&#x0D; Methodology: A total of 80 participants between 20 and 85 years old are recruited in this study, including 40 younger subjects (mean: 23.0; SD: 4.05) and 40 elderly subjects (mean: 69.8; SD: 4.59). They are tasked to sit, walk and run in a conditioning chamber.&#x0D; Findings: Regression equations for predicting the foot skin temperature of the young and elderly people are formulated, with R squares of 0.513 and 0.350 respectively. The level of activity is the most important factor when predicting the foot skin temperature. The material properties of the footwear also show a significant impact on the foot skin temperature of the elderly.&#x0D; Value: The findings of this study provide the basis for better thermal comfort and help to facilitate the footwear design process.

The effects of protective footwear on spine control and lifting mechanics

Manual materials handling is often performed in hazardous environments where protective footwear must be worn; however, workers can wear different types of footwear depending on the hazards present. Therefore, the goal of this study was to investigate how three-dimensional lifting mechanics and trunk local dynamic stability are affected by different types of protective footwear (i.e. steel-toed shoes (unlaced boot), steel-toed boots (work boot), and steel-toed boots with a metatarsal guard (MET)). Twelve males and twelve females performed a repetitive lifting task at 10% of their maximum lifting effort, under three randomized footwear conditions. Footwear type influenced ankle range of motion (ROM). The work boot condition reduced ankle sagittal ROM (p = 0.007) and the MET condition reduced ankle ROM in the sagittal (p = 0.004), frontal (p = 0.001) and transverse (p = 0.003) planes. Despite these differences at the ankle, no other changes in participant lifting mechanics were observed.

The Effect of Footwear on Free Moments During a Rotational Movement in Country Swing Dance.

Footwear in dance has been studied for support and cushioning, but little research has been conducted on free moments, which may result from high frictional coefficients. Conversely, insufficient friction between shoes and floors may increase the risk of falls and compromise dance performance. The purpose of this study was to examine the effect of different types of footwear with different coefficients of friction on peak and average free moments during a rotational movement in country swing dance. Fifteen country swing dancers completed a rotational movement under four footwear conditions: barefoot, rubber-bottom boots, leather-bottom boots, and running shoes. The peak and average free moments applied to the left and right legs were measured using two force plates. Coefficients of static friction between different shoes and force plate surfaces were quantified and found to be greater for the rubber-bottom boots and running shoes than the leather-bottom boots. For the left (push off) leg, free moments were greater for the running shoe and rubber-bottom boot conditions compared to the barefoot and leather-bottom boot conditions. For the right (rotating) leg, free moments were greatest for the running shoe condition, second greatest for the barefoot and rubber-bottom boot conditions, and least for the leather-bottom boot condition. The leatherbottom boots may decrease twisting loads resulting from free moments. Coefficients of friction and free moments should be considered for future longitudinal studies to investigate potential cause-effect relationships among footwear, potential for injury, and dance performance.

Knee Pain and the Use of Various Types of Footwear-A Review.

Knee pain is a highly prevalent condition in the United States with multiple etiologies, with two of the most common sources being osteoarthritis (OA) and patellofemoral pain (PFP). These conditions can lead to reduced physical function and a poor quality of life. Various modalities have been used to decrease the amount of knee pain that individuals' experience; however, they are not always successful and can be expensive. Several studies have reported on specialized footwear for symptomatic alleviation of conditions that affect the knee, this is because it has been theorized that certain footwear can alter the forces placed by muscles on lower-extremity joints, and can potentially alleviate pain by reducing the load placed on the joint. Therefore, the purpose of this study was to review the current literature on the use of various types of footwear used in patients who suffer from knee pain. Specifically, we evaluated: (1) knee OA and (2) PFP and the effect that different footwear has on patients' symptoms. Multiple different types of footwear and orthosis were utilized to treat patients with chronic knee pain. However, the results from reported outcomes by different studies are conflicting, which warrant further studies. Nevertheless, there are enough positive results to view this as a potential major modality to utilize for the treatment of knee OA.

Independent factors associated with wearing different types of outdoor footwear in a representative inpatient population: a cross-sectional study

BackgroundFootwear can have both a positive and negative impact on lower limb health and mobility across the lifespan, influencing the risk of foot pain, ulceration, and falls in those at risk. Choice of footwear can be influenced by disease as well as sociocultural factors, yet few studies have investigated the types of footwear people wear and the profiles of those who wear them. The aim of this study was to investigate the prevalence and factors associated with outdoor footwear type worn most often in a representative inpatient population.MethodsThis study was a secondary data analysis of a cohort of 733 inpatients that is highly representative of developed nations’ hospitalised populations; 62 ± 19 years, 55.8% male, and 23.5% diabetes. Socio-demographic, medical history, peripheral arterial disease, peripheral neuropathy, foot deformity, foot ulcer history, amputation history and past foot treatment variables were collected. Participants selected the footwear type they mostly wore outside the house in the previous year from 16 types of footwear. Multivariate logistic regression identified independent factors associated with outdoor footwear types selected.ResultsThe most common outdoor footwear types were: running shoes (20%), thongs/flip flops (14%), walking shoes (14%), sandals (13%) and boots (11%). Several socio-demographic, medical history and foot-related factors were independently associated (Odds Ratio; 95% Confidence Interval)) with different types of footwear. Running shoes were associated with male sex (2.7; 1.8–4.1); thongs with younger age (0.95 for each year; 0.94–0.97), being female (2.0; 1.2–3.1) and socio-economic status (3.1; 1.2–7.6); walking shoes with arthritis (1.9; 1.2–3.0); sandals with female sex (3.8; 2.3–6.2); boots with male sex (9.7; 4.3–21.6) and inner regional (2.6; 1.3–5.1) and remote (3.4; 1.2–9.5) residence (all, p < 0.05).ConclusionsWe profiled the types of outdoor footwear worn most in a large diverse inpatient population and the factors associated with wearing them. Sex was the most consistent factor associated with outdoor footwear type. Females were more likely to wear thongs and sandals and males boots and running shoes. Overall, this data gives insights into the socio-demographic, medical and other health factors that are related to footwear choice in a large diverse population primarily of older age.

The Differential Effects of Footwear on Sample Entropy of Ground Reaction Force during Running

Maximum cushioned shoes could reduce the peak vertical Ground Reaction Force (GRF) during running, but it may increase the foot instability in horizontal directions, especially at the initial foot contact. Sample entropy (SampEn) has been adopted to define the irregularity to quantify levels of complexity of movement and examine the fluctuations in GRF within a time series. The foot instability would be better represented by the index of SampEn within a stance phase instead of variation among different stance phases viewing instability as errors. PURPOSE: this study was aimed at examining the complexity of GRF while running on the treadmill with different types of footwear through SampEn. METHODS: 19 experienced runners were recruited and ran on the treadmill at 7.8 mph wearing different types of running shoes: max cushioned shoe, minimalist shoe, and regular shoe. GRF of 10 consecutive steps were collected by the instrumented Tandem treadmill. GRF data were further analyzed to calculate sample entropy for both the first 20% stance phase and entire stance phase. Two-way MANOVA was used to examine the effects of independent variables (shoe, step) on sample entropy measures at first 20% stance phase (SampEn20%-ML, SampEn20%-AP, SampEn20%-VT) and entire stance phase (SampEnML, SampEnAP, SampEnVT). Post hoc Tukey test was applied as needed. RESULTS: a significant shoe effect was observed on the association among dependent variables listed above (P < .05). Cushioned shoes displayed a higher SampEnAP (.1162 ± .01558) than regular shoes (.1094 ± .0258) and a greater SampEn20%-AP (.1953 ± .1556) than minimalist shoes (.1546 ± .0932). Minimalist shoe exhibited greater SampEnVT (.0614 ± .01310) and SampEn20%-VT (.0636 ± .0688) than cushioned shoes (.0577 ± .1002; .0448 ± .0305) respectively. No other significant difference was observed. CONCLUSIONS: in general, cushioned shoes displayed more fluctuations of GRF in the anterior-posterior (AP) direction compared to minimalist and regular shoes, which indicates cushioned shoes may increase the foot instability in AP direction during running. Greater fluctuations of vertical GRF when wearing minimalist shoes may indicate a reduced foot stability that could affect the impact absorption at foot touchdown and force generation in push-off.

Effect of Footwear on Dynamic Stability during Single-leg Jump Landings.

Barefoot and minimal footwear running has led to greater interest in the biomechanical effects of different types of footwear. The effect of running footwear on dynamic stability is not well understood. The purpose of this study was to compare dynamic stability and impact loading across 3 footwear conditions; barefoot, minimal footwear and standard running shoes. 25 injury free runners (21 male, 4 female) completed 5 single-leg jump landings in each footwear condition. Dynamic stability was assessed using the dynamic postural stability index and its directional components (mediolateral, anteroposterior, vertical). Peak vertical ground reaction force and vertical loadrates were also compared across footwear conditions. Dynamic stability was dependent on footwear type for all stability indices (ANOVA, p<0.05). Post-hoc tests showed dynamic stability was greater when barefoot than in running shoes for each stability index (p<0.02) and greater than minimal footwear for the anteroposterior stability index (p<0.01). Peak vertical force and average loadrates were both dependent on footwear (p≤0.05). Dynamic stability, peak vertical force, and average loadrates during single-leg jump landings appear to be affected by footwear type. The results suggest greater dynamic stability and lower impact loading when landing barefoot or in minimal footwear.

Medial Longitudinal Arch Development of Children Aged 7 to 9 Years: Longitudinal Investigation.

It is unclear at what age the medial longitudinal arch (MLA) of the foot becomes stable in children. The influence of footwear on MLA development also is unknown. The purpose of this study was to examine the MLA development of children using a longitudinal approach. The relationship between wearing different types of footwear and MLA development also was explored longitudinally. This was a longitudinal cohort observational study. The MLA of 111 healthy children (mean age=6.9 years, SD=0.3) was evaluated using 3 parameters (arch index [AI], midfoot peak pressure [PP], and maximum force [MF]) extracted from dynamic foot loading measurements at baseline (t0), 10-month follow-up (t1), and 22-month follow-up (t2). Information on footwear usage was surveyed. Linear mixed modeling was used to test for differences in MLA over time. The MLA of the children remained stable over time (AI: t0/t1/t2=0.25 [95% confidence interval (CI)=0.24, 0.26]/0.25 [95% CI=0.24, 0.26]/0.25 [95% CI=0.24, 0.26]; P=.95). When the children's sex was considered, the AI of boys decreased (higher arch) with age (0.26 [95% CI=0.24, 0.27]/0.25 [95% CI=0.24, 0.27]/0.25 [95% CI=0.23, 0.27]; P=.02). Boys also displayed a flatter MLA than girls at age 6.9 years (AI: mean difference=0.02 [95% CI=0.01, 0.04]; P=.02). At baseline, children who wore closed-toe shoes displayed the lowest MLA overall (AI: closed-toe shoes/sandals/slippers=0.26 [95% CI=0.24, 0.28]/0.24 [95% CI=0.23, 0.25]/0.25 [95% CI=0.24, 0.26]; P<.01). Children who used slippers at toddlers' age experienced a higher PP (flatter arch) in later childhood than those who wore sandals (mean difference=31.60 kPa [95% CI=1.44, 61.75]; post hoc P=.04). Information on the type of footwear worn was self-reported and, therefore, may be subjected to recall bias. The MLA of children remained stable from 7 to 9 years of age. The child's sex and the type of footwear worn during childhood may influence MLA development.