Yumi Iwakami

Analysis of foot pressure distribution data for the evaluation of foot arch type

In order to develop an evaluation system for foot arch type in the elderly using foot pressure distribution data, foot pressure distribution parameters were selected and the data thereby derived were discussed. Results from the study show that the midfoot area and pressure ratios were correlated to foot arch type determined by visual analysis and were not correlated to arch height parameters. It is assumed that foot pressure distribution parameters reflect a different phenomenon from that of arch height parameters. The inconsistency between them is considered to be a result of the effect of the forefoot arch on the arch height parameters.

Effects of Foot Arch Structure on Postural Stability

Background: In many human postural studies, the foot is considered to be a rigid body. The human foot is composed of the arch structure, which is characteristic in every person and deforms with aging. Foot arch structure is assumed to effect postural control; however, underlying mechanisms remain unclear. The aim of this study was to elucidate the relationship between the structure of the foot arch and postural control in the elderly. Methods: [Protocol 1] Thirty-seven healthy subjects participated in a test to determine the relationship between midfoot plantar pressure and arch height. Midfoot plantar pressure distribution (ratio of MP) was measured using the Shoe Type Stabilometer. The arch height was measured using a three-dimensional foot scanner. [Protocol 2] Ratio of MP and postural stability was measured in 143 elderly subjects using the Shoe Type Stabilometer. Postural stability was evaluated by center of pressure (CoP). Results: In Protocol 1, the correlation coefficient between the ratio of MP and ratio of arch height was r=−0.59 for the left foot and r=−0.54 for the right foot. Therefore, arch height could be predicted by ratio of MP. In Protocol 2, a significant correlation was recognized between the ratio of MP and lower limb strength, CoP total length, area anterior-posterior length, and medial-lateral (ML) length. Conclusions: The Shoe Type Stabilometer could evaluate CoP and foot arch structure. Using this device, it was found that people with a high ratio of MP, who tends to be flat-foot, displayed an increase in CoP sway. Therefore, foot arch structure contributed to postural control. Correlation between the ratio of MP and ML length, and between the ratio of MP and lower limb strength, indicated that the function of the plantar intrinsic foot muscles, which contributes to foot arch structure.

Evaluation of Ambulatory Function by Using the Shoe Device

Hip fracture among the elderly is a serious problem that not only decreases their quality of life (QOL) and activities of daily living (ADL) but also has significant effects on their medical expenses. Therefore, it is necessary to use effective countermeasures to prevent falls among the elderly population. Although various factors are associated with falling, it is thought that three points are important from the perspective of physical function: ambulatory function, balance function, and lower-limb muscle strength. This study focused on quantitative evaluation of the ambulatory and balance functions, and we developed a shoe device to measure plantar pressure under the natural environments of daily life. The device consists of insoles for the shoes with seven-point pressure sensors and wireless communication units. These enable the measurement of physical functions in an unrestrained state. Because falling usually occurs when the individual walks dynamically during daily activities, it is necessary that the method of functional evaluation is suitable for use during the individual’s typical activities.

Relationship between foot arch structure and postural stability — Measurements in over 100 older people for health monitoring

The aim of this study was to investigate the relationship between the structure of the foot arch and postural control in the elderly. Ratio of midfoot pressure (RMP) and CoP was measured in 87 healthy elderly and 56 frail elderly using the Shoe Type Stabilometer we developed. As a result, a significant correlation was recognized between the RMP which correlate foot arch and CoP sway in the healthy elderly. Therefore, foot arch structure contributed to postural control.

Measuring gait pattern in elderly individuals by using a plantar pressure measurement device

BACKGROUND Hip fracture in the elderly is a serious problem, and solutions to prevent falls are needed. OBJECTIVE This study focused on elucidating data critical to fall prevention by evaluating ambulatory function, and we achieved this by developing a plantar pressure measurement device to determine gait function. METHODS Our device enables measurement of gait function in the unrestrained state by transmitting wireless data. In this study, we applied the device to field experiments involving 98 subjects (39 healthy individuals, 44 elderly non-fallers, and 15 elderly fallers). Gait features were determined by measuring the pressure values and foot contact patterns used as gait function parameters in previous studies. RESULTS In particular, decreased peak pressure values were noted at heel strike and toe off during walking in elderly fallers compared with elderly non-fallers. In addition, compared with healthy subjects, elderly fallers also showed extension of the double support phase, and differences in individual gait pattern features were observed between the groups. CONCLUSIONS Experiments confirmed that our device can be used to obtain the gait features of a diverse group of elderly individuals. Moreover, our device enables objective and quantitative evaluation of gait function and thus may be useful for evaluating gait function in the elderly.

Effect of foot load changes on foot arch evaluation using foot pressure distribution data

Background The foot arch serves important functions in regard to shock absorption and the action of walking. Simple and quantitative classification of foot arch types such as flat foot and high arch would be helpful in health support for the elderly. The present authors have developed a classification system for foot arch type showing high reliability using foot pressure distribution data [1,2]. However, effect of foot load changes on foot arch evaluation remains unclear. The aim of this study was to investigate the effect of foot load changes on foot arch evaluation using foot pressure distribution data.

Validation of cleaning evaluation of surgical instruments with RFID tags attached based on cleaning appraisal judgment guidelines

In medical institutions, the threat of infection is closely focused, in particular, inspections regarding surgical site infections (SSI) are carried out. In this study, development of the application of Radio frequency identification (RFID) tags for surgical instrument has been promoted. It enables traceability and individual management of surgical instruments. An experiment was carried out following the cleaning Appraisal guidelines, which contaminated surgical instruments, and using the washer-disinfector (WD) as the main cleaner for surgical instruments with developed RFID tags attached to them. As a result, all of the instruments with RFID tags, the amount of residual protein was less than the recommended acceptable level of 100μg. If WD is used correctly, a sufficient cleaning effect can be expected. From this result, it became evident that the secondary infection risk is low from surgical instrument with RFID tags attached.

Development of an evaluation system for foot arch types in the elderly using foot pressure distribution data

The foot arch serves important functions related to shock absorption and the action of walking. Simple and quantitative classifications of foot arch types, such as flat feet and high arches, help to provide health support services for the elderly. To develop an evaluation system for foot arch types using foot pressure distribution data, discriminant analyses were conducted using data from healthy elderly persons. The midfoot pressure ratio was selected and discriminants were derived. For evaluating the performance of the classification method, the derived discriminants were applied to the data from the other group of healthy elderly persons. Results indicate that both sensitivity and specificity of the classified foot arch types were sufficiently high.

Effect of Exercise Intervention and Foot Load Changes on Foot Arch Evaluation Using Foot Pressure Distribution Data

The foot arch serves important functions in regard to shock absorption and the action of walking. Simple and quantitative classification of foot arch types such as flat foot and high arch would be helpful in health support for the elderly. The present authors have developed a classification system for foot arch type showing high reliability using foot pressure distribution data. However, effect of exercise intervention and foot load changes on foot arch evaluation using foot pressure distribution data remain unclear. The aim of this study was to investigate the effect of exercise intervention and foot load changes on foot arch evaluation using foot pressure distribution data.