Toe Contact Research Articles

Quality of Life, Pedobarographic Parameters, and Foot Disorders in Patients with Extreme Obesity: Preliminary Results on Changes After Bariatric Surgery with Gastric Bypass

PurposeObesity is a growing health problem that affects a high percentage of the population. In podiatry context, few studies have addressed obesity because most pedobarographic systems are unable to bear the weight of patients with obesity, making it difficult to examine and manage these patients. The objective of this study was analyzed the sociodemographic characteristics, quality of life, foot disorders, and pedobarographic parameters of patients with extreme obesity who are candidates for bariatric surgery and determine the changes after weight loss post-surgery.Materials and MethodsWe conducted a foot examination, a pedobarographic study using a Podoprint® pressure platform, and a quality of life questionnaire (EQ-5D) on 23 patients with extreme obesity and analyzed the changes 12–18 months after surgery in 11 of them.ResultsWe observed foot disorders, high plantar pressure, greater rearfoot contact, flat footprint, asymmetries, and alterations in toe contact. Almost 73.9% of participants said they had foot pain, 56.5% said they had impaired mobility, and more than 40% said they had limitations in carrying out daily activities and suffered from anxiety. After weight loss, we observed improved quality of life; more foot disorders; changes in total contact area, plantar pressures, barycenter, contact time, and footprint; decreased pain perception, walking problems and anxiety situations. Moreover, medication decreased, but they need to take more vitamins and calcium.ConclusionWeight loss improved the quality of life of the participating patients but altered their foot disorders. All parameters need regular reassessment to detect changes and modify initially prescribed treatments.Graphical

An exploratory study of dynamic foot shape measurements with 4D scanning system

Accurate and reliable foot measurements at different stances offer comprehensive geometrical information on foot, thus enabling a more comfortable insole/footwear for practical use and daily activities. However, there lacks investigations on continuous deformation of foot shape during the roll-over process. This study analyses the foot deformation of 19 female diabetic patients during half weight bearing standing and self-selected walking speed by using a novel 4D foot scanning system. The scanning system has good repeatability and accuracy in both static and dynamic scanning situations. Point cloud registration for scanned image reorientation and algorithms to automatically extract foot measurements is developed. During the foot roll-over process, maximum deformation of length and girth dimensions are found at first toe contact. Width dimensions have maximum deformation at heel take off. The findings provide a new understanding of foot shape changes in dynamic situations, thus providing an optimal solution for foot comfort, function and protection.

Femoral head reduction osteotomy to improve femoroacetabular containment in Legg-Calve-Perthes disease

OperationszielWiederherstellung der Hüftkongruenz und des Containments durch zentrale Hüftkopfresektion/Reduktion über eine erweiterte chirurgische Hüftluxation unter Erhaltung/Respektierung der Hüftkopfdurchblutung. Eine gleichzeitige oder spätere Reorientierung des Acetabulums durch Triple-Osteotomie oder PAO bei instabiler Hüfte kann in speziellen Fällen notwendig werden.IndikationenDie Indikation zur chirurgischen Hüftkopfreduktion ist praktisch unabhängig vom Alter bei jeglicher inkongruenten, asphärischen Hüftkopfsituation mit „hinged abduction“ (zu erwartende Endsituation wie Stulberg IV und V) gegeben. Dies kann noch bei aktivem wie auch bei bereits ausgeheiltem Morbus Perthes der Fall sein. Zudem kann bei einer Stulberg-V-Situation selbst im adulten Alter noch eine Verbesserung erziel werden. Nach Resektion muss noch ein tragfähiger Resthüftkopf vorhanden bleiben, d. h. mindestens noch 50 % des ausgeweiteten Hüftkopfes. Die dafür beste Planung erfolgt in der „vergleichenden“ 3‑D-Rekonstruktion.KontraindikationenVöllig zerstörter Knorpel oder Hüftkopf.OperationstechnikIdentisches Operationsvorgehen wie für die klassische chirurgische Hüftluxation. Präparation der retinakulären Flaps. Unter Respektierung und in Kenntnis der Gefäßversorgung Spaltung des Hüftkopfes gemäß dem zu entfernenden, nekrotischen Kopfanteil. Bildung eines möglichst sphärischen Hüftkopfes und Verschraubung der beiden Kopfanteile auf Schenkelhalsniveau. Distalisation und Fixierung des großen Trochanters. Je nach Kongruenz und Stabilität des Hüftkopfs in der Hüftpfanne kann eine primäre oder sekundäre Triple-OT oder PAO notwendig werden.WeiterbehandlungDie intraoperative Stabilität des Femurkopfes im Acetabulum muss erzielt worden sein, um eine beckengipsfreie, funktionelle Nachbehandlung zu gewährleisten: Stockentlastung mit Bodenkontakt ist erlaubt; keine aktive Rotation; Flexion aktiv und passiv bis 90 Grad ist erlaubt; vorerst keine spezifische Physiotherapie; je nach Heilungsverlauf sind diese Maßnahmen 8 bis 10 Wochen einzuhalten.ErgebnisseGemäß unseren publizierten Nachuntersuchungen (aktuell 21 Jahre) sehen wir bei technisch korrekt durchgeführter Operation und korrekter Indikation sowie adäquater Nachbehandlung durchwegs gute Ergebnisse. Nekrosen des reduzierten Hüftkopfs haben wir nie beobachtet. Alle gespaltenen Hüftköpfe, respektive Schenkelhälse sind primär geheilt.

Nonlinear dynamical behaviors of spiral bevel gears in transient mixed lubrication

Herein, a new and actual nonlinear dynamic model of spiral bevel gears (SBG) in transient mixed lubrication was firstly developed, which considered the coupling action of direct contact of asperity and the transient squeezing effect of lubricant along the entire contact trajectory in the form of time-variant contact stiffness and damping. Besides, the nonlinear backlash, actual time-variant rotating contact radii and static transmission error obtained by loaded tooth contact analysis (LTCA) method were all involved in this model. Based on the proposed model, notable deviations were found compared with traditional Hertz contact or full-film lubrication assumptions, which highlight the important role of film lubrication and asperity contact. After that, a series of investigations on nonlinear dynamic of SBG were implemented to reveal the influence of lubrication, roughness, applied torque, especially, the influence of contact trajectory which has not been reported. The results demonstrate that the influence of roughness on dynamic response are complicated, and the excessive roughness tends to arise bilateral impact of gear tooth. The effect of transmission torque is more significant than that of contact stiffness and damping. As for different contact trajectories, the vibration response of heel contact is the strongest, while toe contact leads to the weakest vibration.

The Effects of the Rectus Femoris Muscle on Knee and Foot Kinematics during the Swing Phase of Normal Walking

The role of rectus femoris (RF) muscle during walking was analyzed through musculoskeletal models to understand the effects of muscle weakness and hyperactivity. Such understanding is fundamental when dealing with pathological gait, but the contribution of RF as a bi-articular muscle is particularly difficult to estimate. Anybody software was used for inverse dynamics computation, and SimWise-4D for forward dynamics simulations. RF force was changed in the range of 0 to 150%, and the resulting kinematics were analyzed. Inverse dynamics showed a short positive RF power in correspondence with the onset of knee extension in the swing phase. Forward dynamics simulations showed an increasing knee flexion and initial toe contact when the RF force was decreased, and increasing knee extension and difficult foot clearance when the RF force was increased. The step became shorter with both increased and reduced RF force. In conclusion, the RF actively contributes to the knee extension in the swing phase. RF also contributes to obtaining a proper step length and to preparing the foot for initial heel contact. So the effect of RF muscle as a bi-articular muscle seems fundamental in controlling the motion of distal segments. RF overactivity should be considered as a possible cause for poor foot clearance in some clinical cases, while RF weakness should be considered in cases with apparent equinus.

Role of multiple, adjustable toes in distributed control shown by sideways wall-running in geckos

Remarkable progress has been made characterizing one of nature's most integrated, hierarchical structures––the fibrillar adhesive system of geckos. Nonetheless, we lack an understanding of how multiple toes coordinate to facilitate geckos' acrobatic locomotion. Here, we tested the control function of gecko toes by running them on vertical substrates varying in orientation, friction and roughness. Sideways wall-running geckos realigned the toes of their top feet upward to resist gravity. Toe contact area was not compromised, but redistributed. Geckos aligned all toes upward to resist slipping when encountering low-friction patches during sideways wall-running. Negotiation of intermittent slippery strips showed an increased contribution of particular toes to compensate for toes that lost adhesion. Increasing substrate roughness using discrete rods perpendicular to sideways locomotion resulted in geckos bending and/or rotating toes to conform to and even grasp the rods, with potential forces more than five times body weight. Geckos increase their effectiveness of manoeuvrability in demanding environments by taking advantage of the distributed control afforded by multiple toes. Our findings provide insight on biological attachment and offer inspiration to advance gecko-inspired robotics and other biomimetic applications.

Feature Assessment of Toe Area Activity during Walking of Elderly People with Stumbling Experiences through Wearable Clog-Integrated Plantar Visualization System

In this study, we investigated the relationship between toe-area activity and stumbling experiences utilizing our developed sensing system, in order to assess toe-area activity in elderly people with stumbling experiences. The sensing system enables the visualization of the plantar aspect while walking on any surface and under any condition. An image of the plantar aspect is received at a reflecting surface and captured by a camera attached to a clog. The toe-area activity was evaluated by comparing the difference between the toe contact areas at heel-strike and push-off. Thirteen young individuals (nine men and four women, age 22.4 ± 2 years) and nine elderly individuals (five men and four women, age 65.3 ± 2 years) participated in the experiment by walking along a straight line wearing the plantar sensing system on their feet. The analysis found that a low value of the mean toe activity for multiple walking cycles was associated with high stumbling risk, irrespective of age, whereas large variations in toe activity was associated with aging. These results indicate that toe activity can predict stumbling risk irrespective of age. We also found that a large value of the maximum toe activity during multiple walking cycles indicates aging, whereas a low value is associated with high stumbling risk.

Function of Antagonistic Pair of the Bi-articular Muscle of Lower Limb During Toe Contact

Function of Antagonistic Pair of the Bi-articular Muscle of Lower Limb During Toe Contact

A Three-row Opposed Gripping Mechanism with Bioinspired Spiny Toes for Wall-climbing Robots

This paper presents a study of a three-row opposed gripping mechanism made of bioinspired spiny toes. An insect Serica orientalis Motschulsky’s tarsal system was first described and studied. A compliant single spiny toe model was established assuming that the contact asperities were spheres. Following the single toe contact model, a spiny toe array’s contact model was then developed using asperity height’s distribution function. By studying the engaging and disengaging process of the single toe, the mechanical behavior of the toe and toe array were addressed. The toes as well as the arrays were manufactured via rapid prototyping. A customized apparatus using displacement-control method has been carried out to measure the pull-in forces and pull-off positions of the single toe and toe array under various compression conditions. Based on the understanding, a three-row opposed gripping mechanism with radial configuration for wall-climbing robots was designed and fabricated according to the mechanical behaviors of the toe and array. Using an opposed spoke configuration with 3 rows of 31 toes on each linkage array, the mechanism designed as a foot of climbing robots can vertically resist at least 1 kg of load on rough inverted surface, while the maximum normal load is as high as 31 N. The findings may provide a way in developing a high payload wall-climbing robot system for practical applications.

Transient behaviors of friction, temperature and fatigue in different contact trajectories for spiral bevel gears

Abstract The dramatic changes in contact geometry, load, entraining and sliding velocity vectors along contact trajectories of spiral bevel gears may cause significant squeezing action. It suggests that the steady-state analysis at each discrete engaging point cannot effectively describe the tribological behavior in spiral bevel gears. The present study aims to systematically study the transient friction, temperature and contact fatigue behaviors in different contact trajectories for spiral bevel gears based on a newly developed transient mixed EHL model. It shows that the obtained transient friction coefficient is much higher than the steady-state when the gears mesh in the first half of the engagement period. During the entire engagement period, the predicted transient fatigue life is significantly longer than the predicted steady-state fatigue life, which is of importance to the integrated and economical design of spiral bevel gears. The comparison with single half-sine waveform asperity demonstrated that the transient asperity contact pressure is much lower than that in quasi-steady state. The variation of flash temperature appears to be insignificant. Moreover, in different contact trajectories, the weakest point in one engagement period always occurs at a certain point when one teeth pair just finished the engaging-in and another pair of teeth completed engaging-out, and the toe contact exhibits the maximum frictional energy consumption and shortest fatigue life among them.

Technique to reduce the minimum toe clearance of young adults during walking to simulate the risk of tripping of the elderly.

The elderly gait encompasses several disorders, including a lower minimum toe clearance (MTC) to the ground, which is a potential cause of tripping and falling while walking. Devices that assist in the MTC could reduce such risks. However, the development of effective assistive methods and their evaluation in the elderly might jeopardize their safety. To address this, young adults could take the place of the elderly. We present Muscle Activity Restriction Taping Technique (MARTT) that was devised to simulate the healthy-elderly gait characteristics in the young adults, particularly the lower MTC, by restricting the activity of lower-limb muscles. Two different restriction approaches, one that restricts muscles at the shank and the other at the shank and thigh, simultaneously, were tested at different walking speeds. Both approaches achieved a reduction in the MTC, regardless of the walking speed. The MTC was reduced to a median value lower than 10.1 mm, which is within the range of the MTC values reported for the elderly. The reduction of the MTC significantly increased toe contact to the ground. With the restriction of the shank muscles, the toe-contact frequency was more than twice as that in normal walking, and with the restriction of both the shank and thigh muscles, more than five times. In addition, MARTT reproduced the lower step length, the lower single support phase, and the joint motion compensation characteristic of the elderly gait, in the youth.

Effect of toe contact condition during forward stepping on the ground reaction forces during turning movement.

[Purpose] This study aimed to classify the plantar contact condition during forward stepping by focusing on the medial and lateral toes and to elucidate the relationship between the classification and turning movement. [Participants and Methods] The participants were 38 females. The plantar contact condition during forward stepping was evaluated for all participants, and the results were used for the group classification. In all the classified participants, the ground reaction force (GRF) during turning movement was measured. [Results] At sidestep (SS) and cross-step (CS), the peak medial-lateral GRF was significantly smaller in the medial floating toe (MFT) group than in the contact toe (CT) group. At SS, the peak times of the medial-lateral GRF in the MFT and lateral floating toe groups were significantly lesser than those in the CT group. At CS, the push-off peak time of the anterior-posterior GRF was significantly lesser in the MFT group than in the CT group. [Conclusion] The results of this study confirmed that each group classified according to the floating toe classification during forward stepping has different characteristics with respect to the ground reaction force during the turning movement, particularly the medial-lateral ground reaction force and its peak time.

Feedforward neural control of toe walking in humans.

Activation of ankle muscles at ground contact during toe walking is unaltered when sensory feedback is blocked or the ground is suddenly dropped. Responses in the soleus muscle to transcranial magnetic stimulation, but not peripheral nerve stimulation, are facilitated at ground contact during toe walking. We argue that toe walking is supported by feedforward control at ground contact. Toe walking requires careful control of the ankle muscles in order to absorb the impact of ground contact and maintain a stable position of the joint. The present study aimed to clarify the peripheral and central neural mechanisms involved. Fifteen healthy adults walked on a treadmill (3.0kmh-1 ). Tibialis anterior (TA) and soleus (Sol) EMG, knee and ankle joint angles, and gastrocnemius-soleus muscle fascicle lengths were recorded. Peripheral and central contributions to the EMG activity were assessed by afferent blockade, H-reflex testing, transcranial magnetic brain stimulation (TMS) and sudden unloading of the planter flexor muscle-tendon complex. Sol EMG activity started prior to ground contact and remained high throughout stance. TA EMG activity, which is normally seen around ground contact during heel strike walking, was absent. Although stretch of the Achilles tendon-muscle complex was observed after ground contact, this was not associated with lengthening of the ankle plantar flexor muscle fascicles. Sol EMG around ground contact was not affected by ischaemic blockade of large-diameter sensory afferents, or the sudden removal of ground support shortly after toe contact. Soleus motor-evoked potentials elicited by TMS were facilitated immediately after ground contact, whereas Sol H-reflexes were not. These findings indicate that at the crucial time of ankle stabilization following ground contact, toe walking is governed by centrally mediated motor drive rather than sensory driven reflex mechanisms. These findings have implications for our understanding of the control of human gait during voluntary toe walking.

Effect of Injury Prevention Training Program on Kinematics of Drop Jump Tasks: Evaluation with Landing Error Scoring System and Three-Dimensional Kinematic Analysis

The ACL injury prevention program we designed could effectively correct the risky motion pattern associated with increased risk for ACL injury. The Landing Error Scoring System (LESS) has been shown to be a reliable clinical screening tool that was developed to identify individuals at increased risk for noncontact anterior cruciate ligament (ACL) injury through evaluation of landing biomechanics during the drop vertical jump (DVJ) test. In the present study, we developed an ACL injury prevention training program and applied the program to the subjects. Kinematic characteristics during DVJ were assessed by LESS scoring and three dimensional motion analysis system before and after the training intervention. The purpose of this study was to examine whether the training intervention can correct (alter) the kinematics of jump-landing task using the two evaluation systems. Study subjects: Ten female healthy volunteers participated in the study (average age; 20.6 years). The injury prevention training program consisted of turn jump, plyometric exercise, and strengthening training (approximately 20 minutes for one set of exercise) was conducted 3 days a week for a period of 6 weeks. Kinematic analysis using LESS and motion analysis system was performed before and after completion of the whole training program. Jump-landing task according to the LESS protocol. All subjects performed 3 test DVJ trials according to the LESS protocol described by Padua et al. Analysis of video images for LESS scoring. Frontal and sagittal view video data were acquired using standard HD video camcorders (HDR-CX560, Sony, Tokyo, Japan) that were positioned according to the LESS protocol. Three-dimensional motion analysis using Point Cluster Technique Simultaneously, three-dimensional kinematics data were collected using an 8-camera motion analysis system (Vicon motion system, Oxford, UK) with ground reaction forces recorded using a force plate. In order to accurately analyze the sequential change in tibio-femoral spatial relationship at the knee, the Point Cluster Technique (PCT) was utilized. Testing procedure included attachment of multiple reflective markers and use of the special program to analyze the three-dimensional motion for extension/flexion, varus/valgus rotation, internal/external rotation of the tibia with respect to the femur. LESS score at the post-training trial (4.8) was significantly smaller than that for the Pre-training trial (6.2) (P < 0.05) (figure1). Regarding the motion analysis results, the peak knee valgus angle at the post-training trial (5.0°) was significantly smaller than that at the pre-training trial (8.2°) (P < 0.05) ; however, peak knee flexion and tibial rotation angles were not significantly different between pre- and post-training trials. As regards the correlation between the LESS and motion analysis results, significant correlation was found between peak knee valgus angle and LESS score at the pre-training trial (R=0.83, P < 0.05) and the post-training trial (R=0.95, P < 0.05). All subjects experienced internal tibial rotation after toe contact. In addition, there was a moderate correlation between the peak internal tibial rotation angle and the LESS score at both the pre-training and post-training trials (R=0.64 and 0.43 respectively). The results of the present study showed that The ACL injury prevention program successfully decreased knee valgus angle and LESS score. Therefore, the potential effectiveness of the training intervention was confirmed.

An investigation into the cause of the inner dark areas and outer lighter areas (ghosting) seen in dynamically-created two-dimensional bare footprints

Dynamic bare footprints differ from static bare footprints through the presence of additional, lighter markings around the rear of the heel print and apices of the toe print areas. These images can appropriately be described as inner dark and outer ghosting features. To date, the functional cause of both features has not been understood. To gain such an understanding could potentially allow the further development and use of these features in forensic identification.The aim of this project was to investigate the causes of the inner dark and outer ghosting features seen in dynamic bare footprints through an observational, practice-based action research approach within a gait laboratory. Volunteer male participants provided bare footprints on inkless paper taped to a Kistler force plate with video cameras situated either side. Ground reaction force data were collected as the footprints were formed and the event recorded using video cameras to allow these data to be correlated later.The findings suggest that the ghosting at the heel is the result of splaying of the fibro fatty pad, while that at the toes is the result of the distal ends of the toes coming into contact with the ground as the heel is lifted.Footprint, ground reaction force and video data comparisons showed that the inner dark area of the heel print corresponded with the main body of the heel contacting the ground. Outer ghosting corresponded with a backward splaying of the fat pad and the heel strike transient spike in vertical ground reaction force during increased loading. The inner dark area of the toes corresponded with a longer period of toe contact with the ground. Outer ghosting corresponded with the decreasing vertical ground reaction force and shorter contact time as the toes were leaving the ground towards the end of the contact phase of gait.Although the sample size was limited, these are new appreciations which could facilitate the use of the inner dark features in identification to provide additional points for comparison in cases involving dynamic bare footprints. Further work is now indicated to study these features in different populations and under varying conditions.

Push-Off Mechanics in Actual Speed Skating and Slide Board Training: A Pilot Study for Designing Skating Simulator

Objectives: The purpose of this study was to analyze the differences in posture during push-off phase between an actual speed skating condition and on slide-board, and provide the basis for improvement of slide-boards. Methods/Statistical Analysis: Nine speed skaters participated in the experiment. To obtain kinematic data in these two conditions, two methods were taken under consideration for the recording motion. The push-off phase was defined as the time period from the left toe contact on the ice surface to the right toe off which was normalized to 100 data points. Univariate analysis of variance was used to test if the differences between two groups with changing time frame in the whole push-off phase are significant. Findings: The results show that the distance between the two feet on the slide board was much longer, while the angle of rotation of both feet was much smaller in the entire push-off phase. Also, there was no significant difference in hip angle between two situations. The knee angle was significantly higher at the early stage of push - off, and the ankle angle was higher at the end of the push - off phase during the slide board training than the actual skate situation. In conclusion, design constraints limits the space on the slideboard which effects the kinematic parameters and made the distance between the left and right foot more distant, as well as smaller rotations of the push off foot. Current slideboards prefer hip-bending exercises, but they do not help with stretching exercises on the knees and ankles. Application/Improvements: Therefore, the structural design of the slide board can be improved by allowing the skater to perform forward propulsion, but not propel the knee or ankle explosively in the medial-lateral direction at the end of the push-off phase.

Sensor-Based Gait Parameter Extraction With Deep Convolutional Neural Networks.

Measurement of stride-related, biomechanical parameters is the common rationale for objective gait impairment scoring. State-of-the-art double-integration approaches to extract these parameters from inertial sensor data are, however, limited in their clinical applicability due to the underlying assumptions. To overcome this, we present a method to translate the abstract information provided by wearable sensors to context-related expert features based on deep convolutional neural networks. Regarding mobile gait analysis, this enables integration-free and data-driven extraction of a set of eight spatio-temporal stride parameters. To this end, two modeling approaches are compared: a combined network estimating all parameters of interest and an ensemble approach that spawns less complex networks for each parameter individually. The ensemble approach is outperforming the combined modeling in the current application. On a clinically relevant and publicly available benchmark dataset, we estimate stride length, width and medio-lateral change in foot angle up to -0.15 ± 6.09 cm, -0.09 ± 4.22 cm and 0.13 ± 3.78° respectively. Stride, swing and stance time as well as heel and toe contact times are estimated up to ±0.07, ±0.05, ±0.07, ±0.07 and ±0.12 s respectively. This is comparable to and in parts outperforming or defining state of the art. Our results further indicate that the proposed change in the methodology could substitute assumption-driven double-integration methods and enable mobile assessment of spatio-temporal stride parameters in clinically critical situations as, e.g., in the case of spastic gait impairments.

Gender differences of sagittal knee and ankle biomechanics during stair-to-ground descent transition

BackgroundFalls on stairs often result in severe injury and occur twice as frequently in women. However, gender differences in kinetics and kinematics during stair descent are unknown. Thus, this study aimed to determine whether gender differences of knee and ankle biomechanics exist in the sagittal plane during the stair-to-ground descending transition. It was hypothesized that 1) women would reveal higher ground-toe-trochanter angle and lower ground-toe length during stair-to-ground descent transition than men; and 2) women would reveal lower peak knee extension moment during stair-to-ground descent transition than men. MethodsFifteen men and fifteen women were recruited and performed a stair descent activity. Kinetic and kinematic data were obtained using a force plate and motion capture system. FindingsThe women performed the stair descent with a lower peak knee extension moment and a peak knee power at the early weight acceptance phase. The women also revealed a higher ground-toe-trochanter angle and a lower ground-toe length, which indicated a more forward position of the lower extremity relative to the toe contact point at both the initial contact and at the time of peak kinematic and kinetic events. InterpretationThis study found that knee and ankle kinematics and kinetics differed significantly between the genders due to differences in ground-toe-trochanter angle. Women have a different stair descending strategy that reduces the demand of the lower extremity muscle function, but this strategy seems to increase the risk of falls.

Incidence of floating toe and its association with the physique and foot morphology of Japanese children.

[Purpose] Physical development, foot morphology, and toe contact of children aged 3 to 5 years were assessed in order to investigate the relationships between body and foot morphology and the incidence of the condition known as “floating toe”. [Subjects] A total of 198 children, aged 3 to 5 years old, participated in this study. [Methods] Height and weight were measured for body morphology, and foot length and width were measured for foot morphology. Footprint images were taken to calculate the number of floating toes. Information about the children’s height and weight at birth, and the time of starting to walk was obtained from their guardians. [Results] At least one floating toe was observed in 87.7–98.7% of the children depending on their ages. The fifth toe was most commonly affected, occurring in 74.2% of the study population. Among the body and foot morphology parameters, only weight at birth showed a significant but very weak correlation with the number of floating toes. [Conclusion] There was a high incidence of floating toe among the children, with the fifth toe most commonly affected. Floating toe weakly but significantly correlated with weight at birth, but did not correlated with other measures of physique at birth, physical development, or the time of starting to walk.

Robust Automated Step Extraction From Time-Series Contact Force Data Using the PDShoe.

This paper presents a method of stride identification, extraction, and analysis of data sets of time-series contact force data for ambulating subjects both with and without Parkinson's disease (PD). This method has been made robust with the use of seeded K-Means clustering, fast Fourier transformation (FFT) spectral analysis, and minimum window size rejection. These methods combine to produce well selected strides of active walking data. We are able to calculate quality of walking measures of stride duration, stance duration (as percent of gait cycle - %GC), swing duration (%GC), time to maximum heel force (%GC), time to maximum toe force (%GC), time spent in heel contact (%GC), and time spent in toe contact (%GC).