• Journal of Korean Foot and Ankle Society
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• v.26 no.3
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• pp.130-135
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• 2022

Purpose: Smart insoles are wearable devices that are inserted into shoes. Smart insoles with built-in pressure and acceleration sensors can measure the plantar pressure, stride length, and walking speed. This study evaluated the validity and reliability of the plantar pressure measurements of smart insoles during walking on flat ground. Materials and Methods: Twenty one subjects were included in this study. After wearing smart insoles, I-SOL^® (Gilon, Seongnam, Korea), the subjects walked a 10 m corridor six times at a rate of 100 steps/min, and the middle three steps, free from direction changes, were chosen for data analysis. The same protocol was repeated after wearing Pedar-X (Novel Corporation, Munich, Germany), an insoletype plantar pressure measurement equipment with proven validity. The average maximum pressure (P_peak, kPa) and the time at which P_peak appeared (P_time, %stride) were calculated for each device. The validity of smart insoles was evaluated by using the interclass correlation coefficient (ICC) of P_peak and P_time between the two instruments, and Cronbach's alpha was obtained from the P_peak values to evaluate the reliability. Results: The ICC of P_peak was 0.651 (good) in the hallux, 0.744 (good) in the medial forefoot, 0.839 (excellent) in the lateral forefoot, and 0.854 (excellent) in the hindfoot. The ICC of P_time showed 0.868 (excellent) in the hallux, 0.892 (excellent) in the medial forefoot, 0.721 (good) in the lateral forefoot, and 0.832 (excellent) in the hindfoot. All ICC values showed good or excellent results. The Cronbach's alpha of P_peak measured in the smart insoles was 0.990 in the hallux, 0.961 in the medial forefoot, 0.973 in the lateral forefoot, and 0.995 in the hindfoot; all indicated excellent reliability in all areas. Conclusion: The plantar pressure measurements of smart insoles during walking on a flat ground showed validity compared to Pedar-X, and high reliability after repeated measurements.

• Korean Journal of Computational Design and Engineering
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• v.16 no.6
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• pp.391-396
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• 2011

Gait is walking attitude and indicating state. The body's gait is a good mix in the center of body mechanics and exercises to wake up gently at the same time switch is a pass which is complicated at legs various joints. The shifting action what swing phase and stance phase rhythmic movement of body. One from piece moves with different dot. Especially plain walking and stair walking as a vehicle has been used frequently. Characteristics of the stair walking while the balanced the horizontal and vertical movement. Stair walking often takes place in everyday. It requires large range more than walking at plain in the moment and joint range of gait motion. And consistently applied to joints and various types of loads at legs joint may involve joint disorders. In this study, spastic cerebral palsy existing artificial limbs for disabled people when developing calibration equinus deformity patients induce muscle pain when walking on stairs independently, to reduce the research. Comparing the characteristics of the walking up the stairs for analysis patellofemoral joint pain as a result it is to provide engineering data.

• PNF and Movement
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• v.16 no.2
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• pp.267-273
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• 2018

Purpose: Leg length discrepancy (LLD) is one of the risk factors for postural imbalance. This study aimed to investigate the effect of induced leg length discrepancy on the limitation of stability (LOS) and static postural balance. Methods: Thirteen adults (males, 7; females 6) participated in this study. The LOS and static postural balance [sway length, sway area, and sway velocity of center of gravity (COG) displacement] were measured by the balance trainer system. The subjects were asked to move the COG for the anterior, posterior, and left and right directions maximally and to keep standing on the platform with and without induced LLD for 30 s in the open and closed eyes conditions, respectively. The LLD was artificially induced to 2 cm using insole. Wilcoxon test was used to compare the LOS and the static postural balance between with and without induced LLD. Results: The anterior and posterior LOS significantly decreased in induced LLD (p<0.05), and the left and right LOS were not significantly different between with and without LLD (p>0.05). Sway length, sway area, and sway velocity of the COG displacement significantly decreased in induced LLD (p<0.05). Conclusion: This study suggests that induced LLD could decease the antero-posterior LOS and increased the static postural balance. Therefore, the LLD could disturb the postural balance.

• The Journal of Korean Physical Therapy
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• v.24 no.5
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• pp.306-312
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• 2012

Purpose: The purpose of this study was to examine the effect of changes in foot cutaneous sensation on plantar pressure distribution during gait. Methods: Sixteen healthy young subjects participated in this experiment. All subjects performed two trials of walking under three somatosensory conditions induced by a normal facilitatory insole that provides increased plantar sensory stimulation, and application of lidocaine cream to the plantar surface of the foot to reduce the sensitivity of the soles. Semmes-Weinstein monofilaments were used for evaluation of reduced plantar sensation. The Pedar system was used for measurement of pressure distribution at the plantar surface of the foot. Results: Pressure in the lateral midfoot area showed an increase with increasing and decreasing sensory inputs. When sensory input was increased, plantar pressure showed a decrease in the forefoot area. When sensory input was decreased, plantar pressure showed an increase in the lateral forefoot area and a decrease in the hallux area. Conclusion: By altering sensory feedback, plantar pressure distribution is changed during gait. Plantar cutaneous afferents play an important role in plantar distribution.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.1 s.190
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• pp.118-125
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• 2007

In this study, we analyzed the plantar shear stress and normal pressure in lateral heel diabetic foot patients during walking by using in-shoe local shear stress and plantar pressure measurement systems. The shear force transducer based on the magnetic-resistive principle, was a rigid 3-layer circular disc. Shear transducers were mounted on the locations of four metatarsal heads and heel in the insole. Twelve normal subjects and three diabetic foot patients with diabetic neuropathy in the lateral heel participated in this study. The center of pressure in lateral heel diabetic foot patients moved more medially and directed toward the first, medial to the second metatarsal heads, and the hallux during late stance, making pressure at the medial heel and the second metatarsal head significantly larger than in the normal. Shear stress at the heel changed significantly in early stance and the magnitude of shear stresses in each metatarsal head also changed. Further studies would be very helpful to design foot orthoses in patients with diabetic neuropathy or other diseases.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2376-2383
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• 2015

Assistance of the operator’s walking ability while carrying a load is a challenging area in lower limb exoskeletons. We implement an exoskeleton called the Unmanned Technology Research Center Exoskeleton (UTRCEXO), which enables the operator to walk with a load more comfortably. The UTRCEXO makes use of two types of DC motor to assist the hip and knee joints. The UTRCEXO detects the operator’s walking intention including step initiation with insole-type FSRs faster without using any bio-signals and precedes the operator’s step with a reference torque. It not only reduces interaction forces between the operator and the UTRCEXO, but also allows the operator to walk with a load more comfortably. In this paper, we present the UTRCEXO implementing the walking assistance mechanism with interaction force reduction during walking.

• Journal of Korean Physical Therapy Science
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• v.8 no.2
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• pp.1073-1080
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• 2001

The purpose of this study was to determine the effect of lift to the shoe of the affected limb on gait patterns in subjects with hemiplegia. The subjects of this study were 18 post-stroke hemiplegics. For the study, insole of the paretic side was lifted 10 mm higher, and duration of dynamic weight bearing was measured. before and after the lift application. For the measurement of carry-over effect of lift, we got data of there three items prior to and 3 weeks after lift application and 3 days after removal of the lift. Dynamic weight bearing was significantly decreased in heel contact and footflat phases only when just after application of the lift, without any change after 3 weeks application. In heel-off phase, dynamic weight bearing did not show any significant difference between before and just after application of lift whereas significantly decreased after 3 weeks application. According to this study, lift applied to the shoe of the paretic limb was not significantly effect in inducing dynamic weight bearing, but changed a dynamic weight bearing.

• The Journal of Korea Robotics Society
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• v.12 no.2
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• pp.107-115
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• 2017

In this paper, four-bar linkage mechanism for the knee joint is developed which is used in prosthetics. But unlike the prosthetics, the feature of this mechanism is that the instantaneous center of rotation of the four-bar linkages can be moved behind the ground reaction force vector so that it can be passively supported without any external power. In addition, this mechanism is developed similar to the structure of the human knee joint for eliminating the sense of heterogeneity of the wearer. In order to design the mechanism with these two objectives, optimization design process is done using the PIAnO tool and detailed design is carried out through optimized variable values. The developed mechanism is attached to the robot which can assist the hip and ankle joints. In order to verify the operation of the developed knee mechanism, an insole type sensor was attached to the shoes to compare data values before and after wearing the robot. Result data showed that wearer wearing the exoskeleton robot with the knee mechanism was the same value regardless of whether the heavy tool is loaded or not.

• The Journal of Korea Robotics Society
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• v.12 no.2
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• pp.124-131
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• 2017

This paper present a novel approach to control the lower body power assistive exoskeleton system of a HEXAR-CR35 aimed at improving a muscular strength. More specifically the control of based on the human intention is crucial of importance to ensure intuitive and dexterous motion with the human. In this contribution, we proposed the detection algorithm of the human intention using the MCRS which are developed to measure the contraction of the muscle with variation of the circumference. The proposed algorithm provides a joint motion of exoskeleton corresponding the relate muscles. The main advantages of the algorithm are its simplicity, computational efficiency to control one joint of the HEXAR-CR35 which are consisted knee-active type exoskeleton (the other joints are consisted with the passive or quasi-passive joints that can be arranged by analyzing of the human joint functions). As a consequence, the motion of exoskeleton is generated according to the gait phase: swing and stance phase which are determined by the foot insole sensors. The experimental evaluation of the proposed algorithm is achieved in walking with the exoskeleton while carrying the external mass in the back side.

• Science of Emotion and Sensibility
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• v.22 no.3
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• pp.55-64
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• 2019

Stroke is a health problem experienced by many elderly people around the world. Stroke has a devastating effect on quality of life, causing death or disability. Hemiplegia is clearly an early sign of a stroke and can be detected through patterns of body balance and gait. The goal of this study was to determine various feature vectors of foot pressure and gait parameters of patients with stroke through the use of a wearable sensor and to compare the gait parameters with those of healthy elderly people. To monitor the participants at all times, we used a simple measuring device rather than a medical device. We measured gait data of 220 healthy people older than 65 years of age and of 63 elderly patients who had experienced stroke less than 6 months earlier. The center of pressure and the acceleration during standing and gait-related tasks were recorded by a wearable insole sensor worn by the participants. Both the average acceleration and the maximum acceleration were significantly higher in the healthy participants (p < .01) than in the patients with stroke. Thus gait parameters are helpful for determining whether they are patients with stroke or normal elderly people.