In-shoe Pressure Measurement System Research Articles

Comparison of in-shoe plantar pressure between Korean combat boots and running shoes

IntroductionCombat boots are special shoes designed for soldiers to wear during activities in rough terrain, such as long marches or military training. Combat boots have been known to cause high...

E065 Scoping review for the application of centre of pressure for patient or intervention assessment in rheumatoid conditions

Abstract Background/Aims Centre of pressure (COP) is the point on a surface through which a single resultant force appears to act. It has been quantified using various commercially available hardware and software such as force plates, in-shoe and platform pressure measurement systems and used to assess stability and function in gait research. Recently, advancements in technology mean systems are more affordable and portable and therefore may be realistically used within clinic to screen patients or assess intervention effectiveness. However, this would require the translation of research protocols and outcomes to clinical practice with consensus on the effective application of COP data to patient assessment in rheumatology. Our aim was to undertake a scoping review to explore the potential role of COP in patients with rheumatoid conditions. We aimed to determine relevant patient groups, COP technology, protocols, and outcome measures. Methods Three electronic databases were comprehensively searched in August 2022 relating to the key themes of the research question: “centre of pressure” and “arthritis”. Individual search terms were tailored to databases (i.e., MeSH terms and truncation) and combined with Boolean operators. Search results were exported to Microsoft Excel. Initial screening was undertaken to remove duplicates (242 excluded) and paper titles that were unrelated to the topic area (332 excluded). Abstracts of remaining articles (140) were then manually screened by two researchers according to criteria to assess their relevance to the aim. Inclusion criteria included lower-limb arthritis sufferers and quantitative studies with peer-reviewed full-text written in English, published since 1980. Exclusion criteria were the inclusion of post-intervention subjects (i.e., replacement arthroplasty) and literature reviews, editorials, preliminary/pilot studies. Full-text screening was then performed and any discrepancies between individual search results were resolved by a third researcher. Relevant information from the remaining studies was scoped and recorded according to the aim. Results 108 papers were included, and preliminary analysis has identified that 90% included patients with osteo-arthritis and 37% rheumatoid. The focus of articles was the knee joint (69%) and primarily observational studies (61%). COP was used to assess interventions in 36% of papers, 21% were shoes/insoles and 4% activity programs. COP was quantified during walking (41%), standing (49%) and gait-initiation (2%) and primarily using force plates (68%). Pressure technology was used to measure COP in 16% of the research, with commercially available in-shoe (6%) and platform (7%) technology being clearly described in papers. Primary outcome measures quantified displacement (93%), velocity (41%) and variability (21%) qualities using a range of variables. Conclusion COP clearly has a role in research for quantifying stability in patients and changes to gait function in response to interventions. The increasing availability and accessibility of pressure technology facilitates the translation of these to assessment in clinic. Disclosure F.S. Goodwin: Grants/research support; NMAHPs Internship Versus Arthritis (Grant reference 22082). C. Price: None. R. Jones: None.

Validity and reliability of the XSENSOR in-shoe pressure measurement system.

In-shoe pressure measurement systems are used in research and clinical practice to quantify areas and levels of pressure underfoot whilst shod. Their validity and reliability across different pressures, durations of load and contact areas determine their appropriateness to address different research questions or clinical assessments. XSENSOR is a relatively new pressure measurement device and warrants assessment. Does the XSENSOR in-shoe pressure measurement device have sufficient validity and reliability for clinical assessments in diabetes? Two XSENSOR insoles were examined across two days with two lab-based protocols to assess regional and whole insole loading. The whole insole protocol applied 50-600 kPa of pressure across the insole surface for 30 seconds and measured at 0, 2, 10 and 30 seconds. The regional protocol used two (3.14 and 15.9 cm2 surface area) cylinders to apply pressures of 50, 110 and 200 kPa to each insole. Three trials of all conditions were averaged. The validity (% difference and Root Mean Square Error: RMSE) and repeatability (Bland Altman, Intra-Class Correlation Coefficient: ICC) of the target pressures (whole insole) and contact area (regional) were outcome variables. Regional results demonstrated mean contact area errors of less than 1 cm2 for both insoles and high repeatability (≥0.939). Whole insole measurement error was higher at higher pressures but resulted in average peak and mean pressures error < 10%. Reliability error was 3-10% for peak pressure, within the 15% defined as an analytical goal. Errors associated with the quantification of pressure are low enough that they are unlikely to influence the assessments of interventions or screening of the at-risk-foot considering clinically relevant thresholds. Contact area is accurate due to a high spatial resolution and the repeatability of the XSENSOR system likely makes it appropriate for clinical applications that require multiple assessments.

Development of a low-cost textile sensor based insole to monitor foot pressure of diabetic patients

A common but preventable complication of diabetes is diabetic foot ulcer. If appropriate care is not provided such foot lesions progress to the most severe diabetic foot complication, like infection, gangrene, amputation and even death. Diabetic neuropathy results abnormal planter pressure points under the foot and triggers the tendency of foot ulcer. The aim of this paper is to present the development of a low cost, power efficient, soft, lightweight and simple in-shoe planter pressure measurement system. The system is capable to determine the average static pressure under ball and heel of the foot. The insole is comfortable due to the use of textile pressure sensor and its simple data acquisition method makes operation easy for the users. An experiment with 10 participants with and without diabetes was carried out to observe the outcome of the system. The practical implication of this study is to minimise the damage caused by foot ulcer by determining the pressure abnormality at earliest with a fully developed cost effective design. The system is capable to identify the difference in average planter pressure values in different groups of participants. To monitor the foot health proactively, the proposed system is found to be a useful device and can successfully scan the planter pressure under ball and heel of the foot.

Influences Of Sleep Disturbances And Mild Traumatic Brain Injury On Gait Performance Among College Students

Sleep disturbances from stress are common among college students. In addition, student athletes in contact sports (e.g., football and soccer) are at a higher risk of receiving a mild traumatic brain injury (mTBI). Stress-related sleep disturbances and mTBI may provoke cognitive and brain changes associated with gait abnormalities. PURPOSE: to examine the association between stress, sleep disturbances, mTBI and gait performance among college students. METHODS: The control group included 28 college students (11 males, 17 females, age: 22.6±3.2 yrs) and the mTBI group consisted of 12 NCAA Division II men’s and women’s soccer players who indicated a history of concussion (3 males, 9 females, age: 19.6±1.3 yrs). Participants were asked to perform gait analysis with an in-shoe pressure measurement system during and after the midterm exam. Cadence, step time, stride time, stance time and swing time were measured. Meanwhile, 14-days consecutive wrist actigraphy data and three sets of questionnaires were collected to assess their stress, sleep and fatigue. A mixed-design ANOVA was used to compare gait and sleep parameters of mTBI and control groups. RESULTS: The mTBI group had significantly shorter step time (0.54±0.01 vs. 0.58±0.01 s, p=.011) and stance time (0.66±0.01 vs. 0.70±0.01 s, p=.013) compared to the control group. The control group had significantly longer step time and stance time during the midterm exam than after the midterm exam. However, no significant differences of gait parameters were observed for the mTBI group during and after midterm exam. During the exam week, participants in both control and mTBI groups perceived moderate stress and reported 2-3 nights of sleep disturbances. Meanwhile, stress level was positively associated with sleep disturbances, poor daytime functioning, and poor activity correlation. CONCLUSION: Midterm exam as a stressor resulted in sleep disturbances in both mTBI and control groups. This stressor may also cause gait abnormalities of the control group, but not the mTBI group. Another interesting finding is that shorter step time and stance time were observed in the mTBI group. Nevertheless, further studies need to examine whether this is indeed due to mTBI, or the difference between student athletes and non-athletes. Supported by Office of Research and Scholarship at UT Tyler.

Design of a wireless smart insole using stretchable microfluidic sensor for gait monitoring

Wearable sensor enables continuous and ubiquitous real-time monitoring of the gait pattern of a patient and it eliminates the need of frequent visit to the clinics and the use of costly medical facilities. Attaching gait sensors on body, however, may not be easy as most of the reported gait sensors are made of non-stretchable materials and they are non-conformal to human skin. In this paper, we have presented an in-shoe pressure measurement system that is developed using multiple stretchable microfluidic sensors for monitoring gait parameters ergonomically. The sensor here has employed Eutectic Gallium-Indium (EGaIn) as the conductive liquid to fill up a spiral-patterned microchannel which is encapsulated inside an Ecoflex 00–50 elastomer. Fundamental studies have been performed to investigate the sensor’s behaviours when it is exposed to normal and axial applied forces. As proof-of-concept demonstration of the applicability of the proposed sensor for gait monitoring application, we have measured the localised foot pressure and dynamically by attaching two sensors on a shoe insole for detecting pressure changes around the heel and metatarsal regions. The experiment was then extended to evaluate the strain sensing by measuring the ankle angle. It has been shown that data can be captured wirelessly and displayed on a smartphone using the Bluetooth communication protocol. Owing to its unique and stretchable structure, the sensor is able to distinguish walking and running motions by analysing their stance and swing phases. This work has explored the possibility of applying a microfluidic-based structure for designing a wearable gait sensor that has good flexibility.

Plantar Loads of Habitual Forefoot Strikers during Running on Different Overground Surfaces

The objective of this study is to investigate plantar loads characteristics of habitual forefoot strike runners while running on different surfaces. Twenty-six runners (age: 28.2 ± 6.8 y, height: 172.9 ± 4.1 cm, weight: 67.7 ± 9.6 kg, BMI (body mass index): 22.6 ± 2.8 kg/m2, running age: 5.0 ± 4.2 y, running distance per week: 14.6 ± 11.7 km) with habitual forefoot strike participated in the study. Runners were instructed to run at 3.3 ± 0.2 m/s on three surfaces: grass, synthetic rubber and concrete. An in-shoe pressure measurement system was used to collect and analyze plantar loads data. Running on the synthetic rubber surface produced a lower plantar pressure in the lateral forefoot (256.73 kPa vs. 281.35 kPa, p = 0.006) than running on concrete. Compared with the concrete surface, lower pressure–time integrals were shown at the central forefoot (46.71 kPa⋅s vs. 50.73 kPa⋅s, p = 0.001) and lateral forefoot (36.13 kPa⋅s vs. 39.36 kPa⋅s, p = 0.004) when running on the synthetic rubber surface. The different surfaces influence plantar loads of habitual forefoot strikers and runners should choose appropriate overground surface to reduce the risk of lower extremity musculoskeletal injuries.

Effects of metatarsal domes on plantar pressures in older people with a history of forefoot pain

BackgroundForefoot pads such as metatarsal domes are commonly used in clinical practice for the treatment of pressure-related forefoot pain, however evidence for their effects is inconsistent. This study aimed to evaluate the effects on plantar pressures of metatarsal domes in different positions relative to the metatarsal heads.MethodsParticipants in this study included 36 community-dwelling adults aged 65 or older with a history of forefoot pain. Standardised footwear was used and plantar pressures were measured using the pedar®-X in-shoe plantar pressure measurement system. Peak pressure, maximum force and contact area were analysed using an anatomically-based masking protocol that included three forefoot mask sub-areas (proximal to, beneath, and distal to the metatarsal heads). Data were collected for two different types of prefabricated metatarsal domes of different densities (Emsold metatarsal dome and Langer PPT metatarsal pad) in three different positions relative to the metatarsal heads. Seven conditions were tested in this study: (i) control (no pad) condition, (ii) Emsold metatarsal dome positioned 5 mm proximal to the metatarsal heads, (iii) Emsold metatarsal dome positioned in-line with the metatarsal heads, (iv), Emsold metatarsal dome positioned 5 mm distal to the metatarsal heads, (v) Langer PPT metatarsal pad positioned 5 mm proximal to the metatarsal heads, (vi) Langer PPT metatarsal pad positioned in-line with the metatarsal heads, and (vii) Langer PPT metatarsal pad positioned 5 mm distal to the metatarsal heads.ResultsWhen analysed with the mask that was distal to the metatarsal heads, where the plantar pressure readings were at their highest, all metatarsal dome conditions led to significant reductions in plantar pressure at the forefoot compared to the control (no pad) condition (F3.9, 135.6 = 8.125, p < 0.001). The reductions in plantar pressure were in the order of 45–60 kPa. Both the Emsold metatarsal dome and the Langer PPT metatarsal pad, when positioned proximal to the metatarsal heads, managed to achieve this without adversely increasing plantar pressure proximally where the pad was positioned, however the Emsold metatarsal dome was most effective.ConclusionsMetatarsal domes reduce plantar pressure in the forefoot in older people with a history of forefoot pain. All metatarsal dome conditions significantly reduced peak pressure in the forefoot, however metatarsal domes that were positioned 5 mm proximal to the metatarsal heads provided the best balance of reducing plantar pressure distal to the metatarsal heads, where the pressure is at its greatest, but not adversely increasing plantar pressure proximally, where the bulk of the pad is positioned. In this proximal position, the Emsold metatarsal dome was more effective than the Langer PPT metatarsal pad and we cautiously recommend this forefoot pad for alleviating forefoot pressure in older people with forefoot pain.

Continuous Analysis of Running Mechanics by Means of an Integrated INS/GPS Device.

This paper describes a single body-mounted sensor that integrates accelerometers, gyroscopes, compasses, barometers, a GPS receiver, and a methodology to process the data for biomechanical studies. The sensor and its data processing system can accurately compute the speed, acceleration, angular velocity, and angular orientation at an output rate of 400 Hz and has the ability to collect large volumes of ecologically-valid data. The system also segments steps and computes metrics for each step. We analyzed the sensitivity of these metrics to changing the start time of the gait cycle. Along with traditional metrics, such as cadence, speed, step length, and vertical oscillation, this system estimates ground contact time and ground reaction forces using machine learning techniques. This equipment is less expensive and cumbersome than the currently used alternatives: Optical tracking systems, in-shoe pressure measurement systems, and force plates. Another advantage, compared to existing methods, is that natural movement is not impeded at the expense of measurement accuracy. The proposed technology could be applied to different sports and activities, including walking, running, motion disorder diagnosis, and geriatric studies. In this paper, we present the results of tests in which the system performed real-time estimation of some parameters of walking and running which are relevant to biomechanical research. Contact time and ground reaction forces computed by the neural network were found to be as accurate as those obtained by an in-shoe pressure measurement system.

Analysis of Insole Geometry and Deformity by Using a Three-Dimensional Image Processing Technique: A Preliminary Study.

Accurate representation of the insole geometry is crucial for the development and performance evaluation of foot orthoses designed to redistribute plantar pressure, especially for diabetic patients. Considering the limitations in the type of equipment and space available in clinical practices, this study adopted a simple portable three-dimensional (3-D) desktop scanner to evaluate the 3-D geometry of an orthotic insole and the corresponding deformities after the insole has been worn. The shape of the insole structure along horizontal cross sections is defined with 3-D scanning and image processing. Accompanied by an in-shoe pressure measurement system, plantar pressure distribution in four foot regions (hallux, metatarsal heads, midfoot, and heel) is analyzed and evaluated for insole deformity. Insole deformities are quantified across the four foot regions. The hallux region tends to show the greatest changes in shape geometry (17%-50%) compared with the other foot regions after 2 months of insole wear. As a result of insole deformities, plantar peak pressures change considerably (-4.3% to +69.5%) during the course of treatment. Changes in shape geometry of the insoles could be objectively quantified with 3-D scanning techniques and image processing. This investigation finds that, in general, the design of orthotic insoles may not be adequate for diabetic individuals with similar foot problems. The drastic changes in the insole shape geometry and cross-sectional areas during orthotic treatment may reduce insole fit and conformity. An inadequate insole design may also affect plantar pressure reduction. The approach proposed herein, therefore, allows for objective quantification of insole shape geometry, which results in effective and optimal orthotic treatment.

Design of wireless device to measure plantar pressure and gait analysis

Foot plantar pressure is the pressure field that acts between the plantar region of the foot and supporting ground. The pressure exerted on the variable region of the foot can be determined using discrete pressure sensors. Information obtained from these sensors is useful in the measurement of gait and posture for diagnosing various problems associated with a lower limb, footwear design, and sports biomechanics. This project is aimed to design a portable in-shoe plantar pressure and gyroscope-based gait angle measurement system. Six Force Sensitive Resistor (FSR) placed in the sole (hallux, 1st, 5th metatarsal, midfoot lateral, midfoot medial and heel respectively) detects the plantar pressure and gyroscope placed at the ankle, knee and hip help measure the orientation and angle of joint movement during various phases of gait. The study among 16 male and 16 female subjects illustrated the significant pressure variation (p&lt;0.0001, t=5.17 with α=95%). Similarly, there was a significant difference in pressure between normal and fast walking speed (p&lt;0.0001, t=5.88) with mean values of 353Kpa and 426Kpa respectively. The mean pressure value for slow walking speed was 423Kpa while there was no significant variation between slow and normal walking speeds (p=0.62, t=1.98). Plantar pressure increased linearly with an increase in the body weight of a person as well. The mean pressure for the 45-50 age group was 313.25Kpa and that for 70-75 was 449Kpa. The study among 10 diabetics and 10 non-diabetic subjects illustrated significantly higher pressure on 1st and 5th metatarsal on diabetic subjects (p=0.0207 and t=2.536). The movement of ankle, knee and hip joint is visualized using the 3D model of a lower limb through processing software. The study illustrated the range of ankle joint movement between -60(dorsiflexion) to 200(plantarflexion), for knee joint was 00 to 300 (flexion) and that for hip joint was -50(extension) to 400(flexion). There was a significant difference in angular values for all three joints while climbing up and down the staircase as compared to walk in a level surface.

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 ‘big-data’ applications to everyday gait control characteristics.

Automatic Recognition of Gait phases Using a Multiple Regression Hidden Markov Model

This paper presents a new approach for automatic recognition of gait phases based on the use of an in-shoe pressure measurement system and a multiple-regression hidden Markov model (MRHMM) that takes into account the sequential completion of the gait phases. Recognition of gait phases is formulated as a multiple polynomial regression problem, in which each phase, called a segment, is modeled using an appropriate polynomial function. The MRHMM is learned in an unsupervised manner to avoid manual data labeling, which is a laborious time-consuming task that is subject to potential errors, particularly for large amounts of data. To evaluate the efficiency of the proposed approach, several performance metrics for classification are used: accuracy, F-measure, recall, and precision. Experiments conducted with five subjects during walking show the potential of the proposed method to recognize gait phases with relatively high accuracy. The proposed approach outperforms standard unsupervised classification methods (Gaussian mixture model, k-means, and hidden Markov model), while remaining competitive with respect to standard supervised classification methods (support vector machine, random forest, and k-nearest neighbor).

A Graphene-Based Flexible Pressure Sensor with Applications to Plantar Pressure Measurement and Gait Analysis.

In the present study, we propose and develop a flexible pressure sensor based on the piezoresistive effect of multilayer graphene films on polyester textile. The pressure response results from the deformation of graphene conductive network structure and the changes in resistance. Here, we show that the graphene pressure sensor can achieve a sensitivity value of 0.012 kPa, the measurement range can be as high as 800 kPa, and the response time can reach to 50 ms. Subsequently, a stable in-shoe wireless plantar pressure measurement system is developed and dynamic pressure distribution is acquired in real-time. Overall, the graphene textile pressure sensor has the advantage of wide dynamic range, flexibility and comfort, which provides the high possibility for footwear evaluation, clinical gait analysis and pathological foot diagnosis.

In-Shoe Plantar Pressure Profiles in Amateur Basketball Players Implications for Footwear Recommendations and Orthosis Use.

Biomechanical analysis of foot loading characteristics may provide insights into the injury mechanisms and guide orthotic prescription for basketball players. This study aimed to quantify in-shoe plantar pressure profiles in amateur players when executing typical basketball movements. Twenty male university basketball players performed four basketball-specific movement tasks-running, maximal forward sprinting, maximal 45° cutting, and layup-in a pair of standardized basketball shoes fitted with an in-shoe plantar pressure measurement system. Peak pressure (PP) and pressure-time integral (PTI) data were extracted from ten plantar regions. One-way repeated-measures analysis of variance was performed across the tasks, with significance set at P < .05. Distinct plantar pressure distribution patterns were observed among the four movements. Compared with running, significantly higher ( P < .05) PP and PTI of up to approximately 55% were found in sprinting and layup, particularly at the forefoot region. Similarly, significantly higher ( P < .05) PPs and PTIs, ranging from approximately 23% to 90%, were observed in 45° cutting compared with running at most foot regions. Compared with running, sprinting and layup demonstrated higher plantar loading in the forefoot region, and 45° cutting yielded increased plantar loading in most regions of the foot. Understanding the plantar pressure characteristics of different movements may be useful in optimizing footwear designs, orthosis use, or training strategies to minimize regional plantar loading during amateur basketball play.

A stakeholder informed, low-cost, personalised 3D-printed insole for diabetic foot ulcer prevention

Background: Diabetic Foot Ulcer (DFU) incidence will rise in line with the increasing global prevalence of diabetes. Healthcare providers must develop effective interventions that address the needs of patients and clinicians if DFUs are to be prevented. Aim: Engage with stakeholders (patients and clinicians) to inform the development and evaluation criteria of a novel low-cost 3D-printed insole to reduce DFU risk in patients with neuropathy. Method: Data from the transcripts of 15 semi-structured patient interviews and the views of 7 podiatrists were used to develop a consensus statement of insole design specifications. A prototype insole was developed and evaluated against these specifications. Clinical effectiveness was established by comparing reduction in peak plantar pressures and patient perceived comfort of 4 people with diabetic neuropathy whist wearing 1) no insole 2) standard custom insole and 3) 3D-printed insole conditions. The F-scan in-shoe pressure measurement system was used to collect kinetic data. Insoles were presented in a random order with participants blinded to the condition. Results: The 3D-printed insole fulfilled most of the design specifications including being lightweight, easy to clean and walk in. It was more effective at reducing forefoot plantar loads when compared to the standard insole condition, reducing mean peak plantar pressure by 31%, a 4% greater reduction over the standard insole condition. Conclusion: This study provided valuable pilot data for the efficacy, acceptability and future direction of this intervention. The impact of stakeholder involvement on insole design, adherence and ulceration rate need to be evaluated through a clinical trial.

Validity and repeatability of three in-shoe pressure measurement systems

In-shoe pressure measurement devices are used in research and clinic to quantify plantar foot pressures. Various devices are available, differing in size, sensor number and type; therefore accuracy and repeatability. Three devices (Medilogic, Tekscan and Pedar) were examined in a 2 day×3 trial design, quantifying insole response to regional and whole insole loading. The whole insole protocol applied an even pressure (50–600kPa) to the insole surface for 0–30s in the Novel TruBlue™ device. The regional protocol utilised cylinders with contact surfaces of 3.14 and 15.9cm2 to apply pressures of 50 and 200kPa. The validity (% difference and Root Mean Square Error: RMSE) and repeatability (Intra-Class Correlation Coefficient: ICC) of the applied pressures (whole insole) and contact area (regional) were outcome variables. Validity of the Pedar system was highest (RMSE 2.6kPa; difference 3.9%), with the Medilogic (RMSE 27.0kPa; difference 13.4%) and Tekscan (RMSE 27.0kPa; difference 5.9%) systems displaying reduced validity. The average and peak pressures demonstrated high between-day repeatability for all three systems and each insole size (ICC≥0.859). The regional contact area % difference ranged from −97 to +249%, but the ICC demonstrated medium to high between-day repeatability (ICC≥0.797). Due to the varying responses of the systems, the choice of an appropriate pressure measurement device must be based on the loading characteristics and the outcome variables sought. Medilogic and Tekscan were most effective between 200 and 300kPa; Pedar performed well across all pressures. Contact area was less precise, but relatively repeatable for all systems.

Comparison of an inertial sensor based motion measurement system with a 3D-reflex marker based motion capture system

footwear telemetry antenna system, respectively. For running gait, three different running speeds on a treadmill were tested in a systematic order; 3.5m/s, 4.5m/s and 5.4m/s. Descriptive statistics for spatiotemporal parameters were calculated using 10 walking gait cycles and 6 running gait cycles. Gait and running parameter changes were analysed using linear regression. Results: During walking gait, there were statistically significant increases in foot off occurrence (p=0.026) and opposite foot off occurrence (p=0.031), and a statistically significant decrease in opposite foot contact occurrence (p=0.011) when walking at a comfortable speed with the prototype system was compared to walking with no attached device. During running gait at 3.5m/s, there was a statistically significant increase in stride frequency (p=0.025) and a statistically significant decrease in relative stride length (p=0.036) found when running with the prototype system was compared to running with no attached device. However, the magnitude of these statistically significant differences was found to be very small, and not clinically meaningful. Discussion:Wearing the prototype footwear telemetry antenna systemdoes not significantly impact gait or running characteristics and therefore, results obtained using this device would be an accurate representation of natural gait and running in this population. However, further validation tests, comparing real time baropodometric data with that of a force plate platform or in-shoe plantar pressure measurement system during gait and running are necessary prior to clinical and research use. Funding acknowledgement: This research was funded by Science Foundation Ireland, Grant Number 09/IN.1/I2652 1512. Reference [1] Kong PW, De Heer H. Gait Posture 2009;29(1):143–5.

A comparative biomechanical analysis of habitually unshod and shod runners based on a foot morphological difference

Running is one of the most accessible physical activities and running with and without footwear has attracted extensive attention in the past several years. In this study 18 habitually male unshod runners and 20 habitually male shod runners (all with dominant right feet) participated in a running test. A Vicon motion analysis system was used to capture the kinematics of each participant’s lower limb. The in-shoe plantar pressure measurement system was employed to measure the pressure and force exerted on the pressure sensors of the insole. The function of a separate hallux in unshod runners is analyzed through the comparison of plantar pressure parameters. Owing to the different strike patterns in shod and unshod runners, peak dorsiflexion and plantarflexion angle were significantly different. Habitually shod runners exhibited a decreased foot strike angle (FSA) under unshod conditions; and the vertical average loading rate (VALR) of shod runners under unshod conditions was larger than that under shod conditions. This suggests that the foot strike pattern is more important than the shod or unshod running style and runners need to acquire the technique. It can be concluded that for habitually unshod runners the separate hallux takes part of the foot loading and reduces loading to the forefoot under shod conditions. The remaining toes of rearfoot strike (RFS) runners function similarly under unshod conditions. These morphological features of shod and unshod runners should be considered in footwear design to improve sport performance and reduce injury.

A comparison of two total contact cast constructs with variable body mass.

There is a growing body of evidence implicating obesity as having a negative effect on the development and treatment of diabetic foot disease. The aim of this study was to increase the body of knowledge on the effects of obesity on foot function, specifically as it relates to peak plantar pressures in the total contact cast (TCC). Our investigational objectives were to compare the effect of two different TCC designs on mean peak plantar pressures, and to evaluate the efficacy of two TCC constructs with increasing body mass. The primary outcome measure was mean peak plantar pressure in the heel, midfoot, forefoot and first metatarsal as measured with an in-shoe pressure measurement system. The variables were patient weight (from 'normal' body mass index (BMI) to 'overweight', 'obese' and 'morbidly obese') and the TCC construct (with both a standard and alternate cast design). The standard TCC is considered the gold standard for off-loading of the diabetic foot. The alternate TCC was designed to use the essential offloading component of the traditional TCC, namely the total contact leg section, with use of an open cell polyurethane foam to transfer load from the foot to the lower leg, thereby offloading the foot by suspending it within a padded fiberglass walking cast. We did not observe statistically significant differences in mean peak plantar pressures in any plantar foot anatomic area or with any body mass between the two TCC designs. Based on the results, we concluded that the alternate TCC design provides another viable TCC construct option for practitioners working with the neuropathic foot. This investigation also provides specific data on changes that occur in peak plantar pressures with use of the total contact cast and variable BMIs. none.