• PNF and Movement
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• v.19 no.2
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• pp.279-285
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• 2021

Purpose: This study aimed to develop new digital navicular drop test (ND-NDT) equipment and to determine its validity and reliability. Methods: A total of 24 healthy male and female adults, who fully understood the purpose of the study and gave consent to participate in the study, were selected as participants. The NDT and ND-NDT were conducted in the dominant foot of the participants in a random order. For the NDT, the position of the navicular bone was marked with a pen first; then, the height of the navicular bone from the ground was measured in both sitting and standing positions. For the ND-NDT, after the sticker-type reflection markers were attached to the position of the navicular bone, the height of the navicular bone from the ground was measured in both sitting and standing positions. To assess the validity of the diagnostic tests, the same examiner measured the height of the medial longitudinal arch (MLA) three times in both the sitting and standing positions. To assess the inter-rater reliability of the ND-NDT, three examiners, in a random order, attached the sticker-type reflection markers to the position of the navicular bone and then measured the height of the MLA in both positions. Results: In the sitting position, the Pearson correlation coefficient (r) between the two diagnostic tests was very high (r = 0.97) and statistically significant. In the standing position, the Pearson correlation coefficient (r) between the two tests was 0.95, which was also statistically significant. The ICC_2,1 values in the sitting and standing positions were 0.93 and 0.95, respectively, indicating significantly high inter-rater reliability. Conclusion: The ND-NDT equipment showed very high diagnostic validity, as well as excellent inter-rater reliability, indicating the clinical usefulness of the equipment as a diagnostic system for confirming pes planus.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.4
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• pp.269-279
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• 2023

Purpose : The most effective intervention for flat foot is strengthening exercises for the intrinsic and extrinsic of the foot. Additionally, visual feedback is necessary for movement accuracy. However, the effectiveness of the intervention when combined with visual feedback was not revealed. To confirm this, the research was to investigate the effect of visual feedback and a complex exercise program on navicular bone height, plantar pressure, and lower extremity alignment. Methods : The twenty eight adult men and women with flat foot were randomly assigned to group 1 (n=14) and group2 (n=14), group1 performed complex exercises with visual feedback, and group 2 performed only complex exercises. Both groups performed a 40 minute compound exercise program three times a week. Navicular drop test, plantar pressure test, and lower extremity alignment test were performed equally in both group. Results : As a result of comparing the change in navicular height within the group according to the intervention, both groups showed a significant difference before and after the exercise (p>.05). There was not significant difference comparing the difference between the groups in the navicular height (p>.05). Comparing the change in plantar pressure within groups, there was not significant difference in the change in plantar pressure in both groups (p>.05). Coparing the difference before and after exercise between groups, there was not significant plantar pressure (p>.05). Comparing the change in leg alignment within the group, there was a significant difference in the change in ankle before and after exercise in group 1 (p<.05), but there was not significant difference in group 2. There was not significant difference in pelvic tilt and knee tilt before and after exercise in both groups (p>.05). Comparing the before and after exercise difference between groups, there were not significant in all variables of leg alignment (p>.05). Conclusion : The results of this study showed that complex exercise applied to patients with flat foot were effective in increasing the height of the navicular bone and ankle angle, but there was no effect due to visual feedback.

• Physical Therapy Korea
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• v.7 no.3
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• pp.72-80
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• 2000

This study was to investigate the effects of a functional electrical stimulation (FES) on temporal parameters (stride length, step width and cadence) of gait patterns in a patient with right hemiparesis. A single-subject reversal (ABAB) design was used. The subject was a 25-year-old male who had foot drop and circumduction gait pattern. An ink foot-print method was used to assess the temporal parameters of gait between the baseline phase and the intervention phase. FES was applied at 8 m walkway, three times a week for 5 weeks. The results showed that stride length was increased by 4.04 cm and that step width was decreased by 3.93 cm in the intervention phase. There was no difference in cadence between the baseline phase and intervention phase.

• Physical Therapy Korea
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• v.30 no.4
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• pp.281-287
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• 2023

Background: The flexible flatfoot is characterized by a flattening of the foot arch due to excessive bodyweight. The use of shoe insoles or taping methods has been identified as effective in realigning the navicular or calcaneus bones and addressing supination in pronated feet. Objects: This study aimed to analyze the difference between the arch taping attachment method, introduced in a previous study, and a novel taping method designed to provide support to the inner aspect of the heel bone in cases of flexible flatfoot. Methods: A navicular drop test was performed to discriminate flexible flatfoot. To analyze the differences in pressure distribution during walking for each taping method, the subjects underwent testing in the barefoot state with no attachments. The procedure included a sequence of arch taping and heel taping. Subsequent analysis of pressure distribution during walking utilized the GaitRite^® system (GAITRite Gold, CIR Systems Inc.). Results: Arch taping and calcaneus taping significantly reduced the integrated pressure over time and peak pressure on the medial side of the midfoot for both feet compared to the barefoot state. Conclusion: The findings of this study suggest that supporting the inside of the heel through calcaneus taping, without direct stimulation to the longitudinal arch and navicular bone, is an effective intervention for flexible flatfoot.

• Korean Journal of Applied Biomechanics
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• v.22 no.2
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• pp.237-242
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• 2012

The purpose of this study was (a) to develop carbon nanotube-based shock absorbers for reducing potentially harmful impact forces and excessive foot pronation, and (b) to briefly determine how the effects of carbon nanotube-based shock absorbers on biomechanical variance during drop landing. A university student(age: 24.0 yrs, height: 176.2 cm, weight: 679.5 N) who has no musculoskeletal disorder was recruited as the subject. Hardness, specific gravity, tensile strength, elongation, 100% modulus, tear strength, split tear strength, compression set, resilience, vertical GRF, and loading rate were determined for each material. For each dependent variable, a descriptive statistics was used for different conditions. The property test results showed that tensile strength, tear strength, split tear strength, compression set, and resilience in carbon nanotube-based shock absorbers were greater than general Ethylene Vinyl Acetate(EVA). These indicated that resistance against variable strength in developed carbon nanotube-based shock absorbers were greater than general EVA. In vertical GRF of CNTC was less than those of EVA during drop landing and loading rate of CNTC was greater than EVA. It seems that the use of CNT can be a effective way of reducing and controlling shock from impact.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.1
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• pp.47-57
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• 2016

In this paper, we measured human body signals in order to verify a active harness system that we developed for gait and balance training. The experimental procedure was validated by tests with 20 healthy male subjects. They conducted motions of Activities of Daily Living(ADL)(Normal Walking, Stand-to-Sit, Sit-to-Stand, Stair Walking Up, and Stair Walking Down) according to body weight support rates (0%, 30%, 50% of subjects' body weight). The effectiveness of the active harness system is verified by using the results of foot pressure distribution. In normal walking, the decrease of fore-foot pressure, lateral soleus muscle and biceps femoris muscle were remarkable. The result of stand-to-sit results motion indicated that the rear-foot pressure and tibialis anterior muscle activities exceptionally decreased according to body weight support. The stair walking down show the marked drop of fore-foot pressure and rectus femoris muscle activities. The sit-to-stand and stair walking up activities were inadequate about the effect of body weight support because the velocity of body weight support system was slower than male's activity.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.839-847
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• 2020

The purpose of this study was to analyze the effects of ankle flexibility, gender, and Q-angle on the ankle joint injury factors during one leg drop landing. For this study, 16 males(age: 20.19±1.78 years, mass: 69.54±10.12 kg, height: 173.22±4.43 cm) and 16 females(age: 21.05±1.53 years, mass: 61.75±6.97 kg, height: 159.34±4.56 cm) in their 20's majoring in physical education using the right foot as their dominant feet were selected as subjects. First, an independent t-test of joint motion and joint moment according to the experience of ankle injury was conducted to determine the effect of physical characteristics on ankle joint injury during one leg drop landing(α = .05). Second, the variable that showed a significant difference through t-test was set as the dependent variable, and the ankle flexibility, gender difference, and Q-angle were designated as independent variables to use Multiple Linear Regression(α =. 05). As a result of this study, it was found that the group that experienced an ankle joint injury was found to use a landing strategy and technique through adduction of the ankle joint and internal rotation of the knee joint, unlike the group without an injury. It was also confirmed that this movement increases the extension moment of the ankle joint and decreases the extension moment of the hip joint. In particular, it was found that the dorsi flexion flexibility of the ankle affects the ankle and knee landing strategy, and the gender difference affects the ankle extension moment. Therefore, it was confirmed that physical characteristics factors affecting ankle joint injuries during one leg drop landing.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.4
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• pp.341-348
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• 2004

This study experimented dividing compaction load by dynamic compaction test and an oil pressure hammer compaction test for consolidation strength characteristics experimental feedback about soil change aspect of waste landfill ground and revelation of compaction effect as underground research about consolidation behavior of waste landfill ground by compaction load, foot weight and percussion number of times were adapted differently each other with uniformity drop head when dynamic compaction test, and hammer scale and percussion number of times were adapted differently also when oil pressure hammer compaction test.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.4
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• pp.1064-1081
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• 2014

This paper presents a numerical analysis of slamming and whipping using a fully coupled hydroelastic model. The coupled model uses a 3-D Rankine panel method, a 1-D or 3-D finite element method, and a 2-D Generalized Wagner Model (GWM), which are strongly coupled in time domain. First, the GWM is validated against results of a free drop test of wedges. Second, the fully coupled method is validated against model test results for a 10,000 twenty-foot equivalent unit (TEU) containership. Slamming pressures and whipping responses to regular waves are compared. A spatial distribution of local slamming forces is measured using 14 force sensors in the model test, and it is compared with the integration of the pressure distribution by the computation. Furthermore, the pressure is decomposed into the added mass, impact, and hydrostatic components, in the computational results. The validity and characteristics of the numerical model are discussed.

• Journal of Environmental Science International
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• v.32 no.5
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• pp.375-384
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• 2023

Climate data were obtained over an eight-year period (July 2013 to June 2021) using an automatic weather observation system (AWS) installed at the foot of Mt. Geumo in Chilgok, Gyeongbuk. Using climate data, the statistical and meteorological characteristics of the local circulation between the Nakdong River and Mt. Geumo were analyzed. This study is based on automatic weather observation system data for Dongyeong, along with comparative climate data from the Korea Meteorological Administration (Chilgok) and the Gumi meteorological observatory. Over the eight- years, mountain and valley winds have occurred 48 times a year on average, with the highest occurring in May and the weakest winds in June and December. When mountain winds occurred, the temperature in the nearby lowland region more strongly decreased than when valley winds blew. However, the potential to use mountain winds to improve urban thermal environments is limited because mountain winds occur infrequently in summer when a drop in nighttime temperature is required.