Jolanta Pauk

Epidemiologic Factors Affecting Plantar Arch Development in Children with Flat Feet

BACKGROUND Foot problems are reported by approximately 70% to 80% of adults and 30% of children. One of the most important characteristics affecting its incidence is medial longitudinal arch. Assessing arch height provides valuable information for prescribing appropriate footwear that reduces the consequences of flatfoot. The main goals of this study were to explore epidemiologic factors that affect arch height and to predict arch height in children with flatfoot based on five variables using widely accessible, low-cost tools. METHODS This study examined plantar arch height in 80 children with flatfoot aged 7 to 15 years. The evaluation criteria included low arch height, correct knee and heel position, and correct body symmetry. To measure arch height, the children sat in a chair and placed their feet on level ground. A caliper was used to measure the height between the bottom of the navicular tuberosity and the floor. Using least mean square error scheme, a multivariable model was fitted to the plantar arch height for all of the participants using independent variables, including age, Cole index, sex, place of residence, and physical activity. RESULTS Arch height increased as age increased in boys and girls in rural and urban areas. A significant increase in arch height occurred in 12- to 15-year-old boys and 10- to 15-year-old girls. In boys, arch height was 30% lower than in girls (P = .05). In children in cities, arch height was lower by 26% than in children in rural areas (P = .05). Arch height increased by 41.8% in inactive boys and by 115.2% in inactive girls in rural areas. It was reduced by 59.4% in boys and by 47.4% in girls as the Cole index increased from 82.2 to 152.0. The suggested model predicted arch height using the childs age, Cole index, sex, place of residence, and physical activity (r > 0.97, error < 0.04 mm [2%], P < .05). CONCLUSIONS Flat feet in children may be affected by age, sex, Cole index, place of residence, and physical activity. The proposed model allows plantar arch heights in children with flat feet to be predicted without the need for sophisticated technology via controlling the childs weight and physical activity for prescribing appropriate footwear.

Assessing plantar pressure distribution in children with flatfoot arch: Application of the Clarke angle

BACKGROUND Flatfoot, or pes planus, is one of the most common foot posture problems in children that may lead to lower-extremity pain owing to a potential increase in plantar pressure. First, we compared plantar pressure distribution between children with and without flatfoot. Second, we examined the reliability and accuracy of a simple metric for characterization of foot posture: the Clarke angle. Third, we proposed a mathematical model to predict plantar pressure magnitude under the medial arch using body mass and the Clarke angle. METHODS Sixty children with flatfoot and 33 aged-matched controls were recruited. Measurements included in-shoe plantar pressure distribution, ground reaction force, Clarke angle, and radiography assessment. The measured Clarke angle was compared with radiographic measurements, and its test-retest reliability was determined. A mathematical model was fitted to predict plantar pressure distribution under the medial arch using easy-to-measure variables (body mass and the Clarke angle). RESULTS A high correlation was observed between the Clarke angle and radiography measurements (r > 0.9; P < 10(-6)). Excellent between- and within-day test-retest reliability for Clarke angle measurement (intraclass correlation coefficient, >0.9) was observed. Results also suggest that pressure magnitude under the medial arch can be estimated using the Clarke angle and body mass (R(2) = 0.95; error, <0.04 N/cm(2) [2%]). CONCLUSIONS This study suggests that the Clarke angle is a practical, reliable, and sensitive metric for quantification of medial arch height in children and could be recommended for research and clinical applications. It can also be used to estimate plantar pressure under the medial arch, which, in turn, may assist in the timely intervention and prognosis of prospective problems associated with flatfoot posture.

The Effect of Foot Orthotics on Arch Height: Prediction of Arch Height Correction in Flat-foot Children

Prognosis of the arch height correction could provide valuable information in prescribing appropriate treatment to reduce the consequences of flat-foot. The goal of this study was twofold. First we explored effect of foot orthotics wedging on the gait pattern of flat-footed children population. Then a simple model to predict arch height correction using six variables was proposed. Measured parameters included the arch height, X-ray measurement, and ground reaction force (GRF). The suggested model allows predicting of the arch height correction. The results show that foot orthotics has small, but a positive impact on the arch height correction.

Low Power, Low Chip Area, Digital Distance Calculation Circuit for Self-Organizing Neural Networks Realized in the CMOS Technology

This paper presents a new distance calculation circuit (DCC) that in artificial neural networks is used to calculate distances between vectors of signals. The proposed circuit is a digital, fully parallel and asynchronous solution. The complexity of the circuit strongly depends on the type of the distance measure. Considering two popular measures i.e. the Euclidean (L2) and the Manhattan (L1) one, it is shown that in the L2 case the number of transistors is even ten times larger than in the L1 case. Investigations carried out on the system level show that the L1 measure is a good estimate of the L2 one. For the L1 measure, for an example case of 4 inputs, for 10 bits of resolution of the signals, the number of transistors is equal to c. 2500. As transistors of minimum sizes can be used, the chip area of a single DCC, if realized in the CMOS 180 nm technology, is less than 0.015 mm2.

Data Mining in Analysis of Biomechanical Signals

In the paper the procedure of processing biomechanical data has been proposed. It consists of selecting proper noiseless data, preprocessing data by means of model’s identification and Kernel Principal Component Analysis and next classification using decision tree. The obtained results of classification into groups (normal and two selected pathology of gait: Spina Bifida and Cerebral Palsy) were very good.

Research of Muscular Activity during Gait of Persons with Cerebral Palsy

Assessing muscular activity during gait in CP persons could provide valuable information in prescribing appropriate treatment to reduce the consequences of cerebral palsy as well as limiting further complication in cerebral palsy children. The main goal of this study was explored working regularities of muscle pairs in children population to show dependencies and variation on gait parameters. Functional evaluation was carried out on 20 cerebral palsy patients. The research have been done by using the system EMG. A surface electrode picked up on the main groups of muscles of lower limbs: the Rectus Femoris, the Vastus Lateralis, the Medial Hamstrings, the Lateral Gastrocnemius, and the Anterior Tibialis. There were several phases to the signal approach such as: data acquisition, data pre-processing, data modeling, data analysis and interpretation. From the results seen that for each task subjects have different strategies for keeping balance during walk depending on the basic level of muscle contraction or antagonistic and synergistic contraction required for that activity.

A Comparative Study of Different Neighborhood Topologies in WTM Kohonen Self-Organizing Maps

In this paper we present a software model of the Winner Takes Most (WTM) Kohonen neural network (KNN) with different types of the neighborhood grid. The proposed network model allows for analysis of the convergence properties such as the quantization error and the convergence time for different grids, which is essential looking from the hardware implementation point of view of such networks. Particular grids differ in complexity, which in hardware implementation has a direct influence on power dissipation as well as on chip area and the final production cost. The presented results show that even the simplest rectangular grid with four neighbors allows for good convergence properties for different training data files.

Image Processing Techniques for ROI Identification in Rheumatoid Arthritis Patients from Thermal Images

Abstract Rheumatoid arthritis (RA) is a systemic autoimmune disease that manifests itself by joint inflammation, swelling, pain, tenderness and may involve extra-articular organs in severe cases. Joint inflammatory lesions are associated with higher temperature due to increased vascularity in the area of inflamed tissues. This papers aimed to identify heat patterns from ROIs to interpret the presence of inflammation in rheumatoid arthritis patients. The thermovisual image sequences were collected from 65 patients with Rheumatoid Arthritis (RA). Infrared images were generated by a thermal scanning camera (FLIR E60bx Systems Inc., USA). Separate recordings of left and right foot temperature changes were performed for 3 minute periods. The temperature measurement was performed at the moment right after cold water immersion (post-cooling temperature) and at the moment after thermal recovery (post-recovery temperature). The recording of 3-minute foot thermal recovery was used for analysis. Automatically identified ROI corresponds to the area of the soft tissues covering cuboid and navicular bone.

ALTERNATIVE METHOD OF UPPER EXTREMITY FUNCTION ASSESSMENT OF STROKE PATIENTS BY ANGULAR KINEMATIC PARAMETERS

This study focuses on the functional assessment of the upper extremity of stroke patients via analysis of angular kinematics features. Amplitudes and angular velocities of multi-joint movements more precisely describe functional state at different impairment levels. However, the arm movement as a whole could be analyzed by means of joint angle–angle diagrams, which illustrate the 2D trajectory of upper extremity during movement and show the visual ranges of upper extremity in different cycles of motion. The functional range of motion of each upper extremity segment in all patient groups for more accurate assessment of capability was calculated. Moreover, we calculated the area (S) between two curves in joint angle–angle diagrams as a novel index of the complete upper extremity movement range evaluation. Our findings correspond to clinical rates and upper extremity assessment based on joint angle–angle diagrams seems to be a promising method for accurate assessment and/or predicting the outcomes of rehabilitation programs.

GAIT DEVIATIONS IN CHILDREN WITH CLASSIC HIGH-FUNCTIONING AUTISM AND LOW-FUNCTIONING AUTISM

The most significant symptoms of autism are abnormal movement patterns that can lead to the decrease of life quality. The purpose of the study was to compare quantitatively the gait strategy of the typical subjects, children with classic high-functioning autism (HFA), and children with low-functioning autism (LFA). Secondly, the comparison and the evaluation of main changes of plantar pressure parameters between groups were presented. The evaluation was carried out on 18 children with HFA, 10 children with LFA, and 30 age-matched children as a control group. A six camera motion capture system, two force plates and a pedobarograph were used to measure gait kinematics, joint kinetics, and pressure distribution under foot during walking. The analysis shows significant differences between children with HFA, LFA, and typical children in velocity, cadence, and magnitude of plantar pressure distribution. The magnitude of plantar pressure was reduced in children with autism under all anatomical masks, which was caused by plano-valgus deformity. Differences were also observed in joint angles and moments during gait cycle. Some of the results can be a source of important information about gait patterns in autistic children. Any exercise treatment prescribed for autistic children should focus on changing the patterns of plantar pressure distribution, which would be similar to patterns of typical children. However, the exercise treatment cannot be generalized due to the high inter-subject variability in children with autism.