• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.633-634
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• 2009

• ETRI Journal
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• v.42 no.1
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• pp.46-53
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• 2020

Gait analysis is an effective clinical tool across a wide range of applications. Recently, inertial measurement units have been extensively utilized for gait analysis. Effective gait analyses require good estimates of heel-strike and toe-off events. Previous studies have focused on the effective device position and type of triaxis direction to detect gait events. This study proposes an effective heel-strike and toe-off detection algorithm using a smart insole with inertial measurement units. This method detects heel-strike and toe-off events through a time-frequency analysis by limiting the range. To assess its performance, gait data for seven healthy male subjects during walking and running were acquired. The proposed heel-strike and toe-off detection algorithm yielded the largest error of 0.03 seconds for running toe-off events, and an average of 0-0.01 seconds for other gait tests. Novel gait analyses could be conducted without suffering from space limitations because gait parameters such as the cadence, stance phase time, swing phase time, single-support time, and double-support time can all be estimated using the proposed heel-strike and toe-off detection algorithm.

• CELLMED
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• v.5 no.2
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• pp.10.1-10.3
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• 2015

Arthritis is a major cause of joint pain, stiffness, and subsequent disability which adversely affects quality of life. Seriously, it can lead to long term social and psychological effects including loss of independence, depression, and anxiety. Arthritis is usually treated with joint replacement surgery or medications. However, the artificial joint is temporary and pharmacological measures have side effects, such as addiction or hypersensitivity. Thus, orthotics has been developed to improve arthritis as a nonpharmacological measure. The increased regional load across compartments of articular cartilage is an important factor in the cause of the arthritis. Mubal$^{(R)}$, a clinical shoe insole, has a sliding function to help people to walk straight and realign the body balance. The slide of Mubal$^{(R)}$ reduces the knee joint loading in patients with arthritis. In addition, pumping function of Mubal$^{(R)}$ can mitigate arthritis by stretching the squashed nerves from lumbar to cervical vertebral and actively circulating blood of pelvic limb. In addition, Mubal$^{(R)}$ could help to stimulate the growth plate. Therefore, Mubal$^{(R)}$ can be used for the child with short stature as well as patients with arthritis.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.11-17
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• 2019

Plantar pressure data can be used not only for walking patterns in daily life, but also for eating, health care, and disease prevention. For this reason, the importance of plantar pressure measurement has recently increased. However, most systems that can measure both static and dynamic plantar pressure at the same time are expensive, not portable, and not universal. In this study, we propose a system that effectively reduces the number of sensors in plantar pressure system. Through this, we want to increase the economics and practicality by reducing the size and weight of the system, as well as the power consumption. First, for static plantar pressure and dynamic plantar pressure, the values measured by existing precision instruments are analyzed to determine how many measurement parts the insole is divided into. Next, for the divided measuring parts, the position of the sensor is determined by calculating the Center of Pressure (COP) for each part with the values of all dynamic and static plantar pressure sensors. Finally, in order to construct a personalized plantar pressure measurement system, we propose a weighting method for the static plantar pressure COP and the dynamic plantar pressure COP for each part.

• The Journal of Korean Physical Therapy
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• v.30 no.6
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• pp.224-228
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• 2018

Purpose: The most common cause of plantar ulceration is an excessive plantar pressure in patients with peripheral neuropathy. Foot orthosis and therapeutic footwear have been used to decrease the plantar pressure and prevent the plantar ulceration in in diabetes patients. We investigated whether protective sock with functional insoles reduce plantar pressure while walking in 17 diabetes patients. Methods: An in-shoe measurement device was used to measure the peak plantar pressure while walking. Peak plantar pressure data were collected while walking under two conditions: 1) wearing diabetic sock and 2) wearing the protective sock with functional insoles. Each subject walked 3 times in 10-m corridor under three conditions, and data were collected in 3 steps in the middle of corridor with in right and left feet, respectively. Pared t-test was used to compare the peak plantar pressures in three plantar areas under these two conditions. Results: The protective sock with functional insoles significantly reduced the peak plantar pressure on the lateral rearfoot, but significantly increased the peak plantar pressure on the middle forefoot, and medial midfoot (p<0.05). However, there were not significant in medial and lateral forefoot, lateral midfoot, and medial rearfoot between diabetic sock and the protective sock conditions (p>0.05). Conclusion: The protective sock with functional insoles reduced plantar pressures in the rearfoot and supported the medial longitudinal arch. However, it is necessary to change the position of metatarsal pad in the insole design of forefoot area to prevent diabetic foot ulceration.

• Journal of Convergence for Information Technology
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• v.10 no.2
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• pp.184-192
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• 2020

This study presents a gait analysis method (including time series analysis) using a smart insole as an objective and quantitative evaluating method after lumbar scoliosis surgery. The participant is a degenerative lumbar scoliosis patient. She took 3-min-gait-test four times(before and 8, 16, and 204-days after surgery) and 6-min-gait-test once(204-days after surgery) with smart-insoles in her shoes. Each insole has 8-pressure sensors, an accelerometer, and a gyroscope. The measured values were used to compare the characteristics of gait before and after surgery. The analysis showed that all of the patient's gait parameters improved after surgery. And after 6 months, the gait was more stable. However, after long walk, the swing duration of one leg was slightly shorter than that of the other again. It was a preclinical problem that could not be found in the visual examination by the practitioner. With this analysis method we could evaluate the improvement of patient quantitatively and objectively. And we could find a preclinical problem. This analysis method will lead to the studies that define and distinguish gait patterns of certain diseases, helping to determine appropriate treatments.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.4
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• pp.291-298
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• 2021

Purpose: The Pedisole is a newly developed shoe-mounted wearable assessment system for analyzing balance and gait. This study aimed to determine the reliability and validity of the parameters provided by the system for static balance and gait analysis of healthy adults. Methods: This study included 38 healthy adults (22.4±1.9 years) with no history of injury in the lower limbs. All participants were asked to perform balance and gait tasks for undertaking measurements. For analysis of balance, both the smart Pedisole and Pedoscan systems were concurrently used to analyze the path length of the center of pressure (COP) and the weight ratio of the left and right for 10 s. Gait was measured using the smart Pedisole and GaitRite walkway systems simultaneously. The participants walked at a self-selected preferred gait speed. The cadence, stance time, swing time, and step time were used to analyze gait characteristics. Using the paired t-test, the intra-class coefficient correlation (ICC) was calculated for reliability. The Spearman correlation was used to assess the validity of the measurements. In total, data for balance from 36 participants and the gait profiles of 37 participants were evaluated. Results: There were significant differences between the COP path lengths (p<.050) derived from the two systems, and a significant correlation was found for COP path length (r=.382~.523) for static balance. The ICC for COP path length and weight ratio was found to be greater than .687, indicating moderate agreement in balance parameters. The ICC of gait parameters was found to be greater than .697 except for stance time, and there was significant correlation (r=.678~.922) with the GaitRite system. Conclusion: The newly developed smart insole-type Pedisole system and the related application are useful, reliable, and valid tools for balance and gait analysis compared to the gold standard Pedoscan and the GaitRite systems in healthy individuals.

• Korean Journal of Applied Biomechanics
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• v.25 no.4
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• pp.475-482
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• 2015

Objective : The purpose of this study was to investigate mean plantar foot pressure, maximum plantar pressure and ground reaction force, and center migration path of pressure according to the type of trekking shoes for the development of shoes. Method : Subjects of the study averaged $22.10{\pm}2.05years$ of age. Their average height was $169.27{\pm}7.62cm$ and their average weight was $64.34{\pm}10.22kg$. The method of this study was administered measuring 50 steps, at once, 3 times at a speed of 4 km/h and using the data of 30 steps. Pedar-X system measured the mean foot pressure, maximum foot pressure, mean maximum force, and center migration path of pressure by subjects' position while walking. Statistical analysis was performed by SPSS 23.0 using a paired t-test. Results : Results of the study showed Nestfit trekking shoes lower foot pressure of both feet in mean foot pressure and maximum foot pressure. Nestfit trekking shoes showed high ground reaction force (p<.001) in the midfoot, and low mean ground reaction force in the rearfoot. The center migration path of pressure showed the Nestfit trekking shoes were more stable than flat insole trekking shoes. Conclusion : It can be concluded that wearing Nestfit trekking shoes spreads pressure efficiently and induces walking stability because Nestfit trekking shoes spread the pressure of the forefoot and rearfoot to the midfoot and the center migration path of pressure shows regularly.

• Journal of Korean Foot and Ankle Society
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• v.8 no.1
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• pp.16-21
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• 2004

Purpose: To investigate the characteristics of the patients and therapeutic shoes for diabetic patients. Materials and Methods: Forty two diabetic patients who had their own therapeutic shoes which were prescribed somewhere else were studied from March 2003 to December 2003. There were 27 males and 15 females, and the mean age was 62.1 years (range, 49-72 years). Duration of diabetes was average 14 years (range, $6{\sim}30$ years), all had type 2 diabetes. Sensation was examined with 5.07 nylon monofilament. The route of purchasing the shoes, compliance to the prescribed shoes were investigated by interview. The shape of shoe, stiffness of upper, conformity of insole to the shape of the foot were recorded. In-shoe plantar pressure was measured in 15 patients. Results: Eighteen patients were insensate to the monofilament. Seven patients did not wear the therapeutic shoes, and only 18 of 35 patients were wearing the therapeutic shoes more than 6 hours a day. The shoes of 17 patients were prescribed by medical doctor and the rest were purchased by the recommendation of acquaintances or advertisement. Ulcer recurred in four of five patients to whom the shoe was prescribed by medical doctor and the cause of three recurrences were evident by just observing the foot and shoe. The therapeutic shoes were made from 11 different makers. Eight shoes were adequate for diabetic patients with respect to the material, shape of insole, type of shoe. In-shoe plantar pressure was examined in 15 patients and was less than 300 kPa in all patients. Conclusion: The therapeutic shoes for the diabetic patients need to be prescribed by medical doctor for selective patients with neuropathy or previous history of ulcer and follow-up examination is important to monitor the compliance of the patients and adequacy of the shoes.

• Korean Journal of Computational Design and Engineering
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• v.17 no.3
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• pp.149-155
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• 2012

The ankle over-pronation causes the mechanical overloading transferred to proximal areas (i.e. knees or hips) over time. Thus, the over-pronation is recognized as a contributory factor in a wide variety of musculo-skeletal pathologies in lower extremities. Commonly, over-pronated ankles are treated using specially designed insoles that support medial heels and correct the posture of lower limbs. However, the biomechanical effects of the insoles are not yet fully understood, so there still are controversies whether such insoles really have clinical significance. In this study, in order to verify the effects of insoles and determine the best shape of the insoles, we examined how the medio-lateral knee joint reaction force changes due to insole conditions through a case study about a subject. As a result, it is revealed that the medial heel post, which drastically reduced the peak medio-lateral knee joint reaction force, has significant effects on the gait of the over-pronated patients. However, in case that the arch support is combined together, the positive effect of the medial heel post may rather decrease.