• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.83-98
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• 2004

The purpose of this study was to investigate the test-retest of plantar pressures using the F-Scan system over speeds and plantar regions. 6 healthy female subjects in 20's were recruited for the study. Plantar pressure measurements during locomotor activities can provide information concerning foot function, particularly if the timing and magnitude of the loading profile can be related to the location of specific foot structures such as the metatarsal heads. The Tekscan F-Scan system consists of a flexible, 0.18mm thick sole-shape having 1260 pressure sensors, the sensor insole was trimmed to fit the subjects' right. left shoes - sneakers shoes & dress shoes. It was calibrated by the known weight of the test subject standing on one foot. The Tekscan measurements show the insole pressure distribution as a function of the time. This finding has important implications for the development of plantar pressure test protocols where the function of the forefoot is important. According to the result of analysis it is as follows 1) Center of force trajectory in women's dress shoes display direct movement, compare with center of force trajectory in Sneaker shoes displays a little bit curved slow pronation movement. Sneaker shoes in forefoot part display very quick supination movement, therefore, this shoes effects negative effectiveness for ankle's stability Considering center of force trajectory analyzing the more center of force close straight line, the more movement can be quick movement for locomotion. For foot pressure distribution, center of force trajectory in locomotion is better to curved trajectory with pronation movement. So sneaker shoes style is good shoes considering center of pressure distribution trajectory compare with women's dress shoes. 2) Women's dress shoes increased peak pressure in medial, this is effected by high hill's height. The more increased women's dress shoes's height, the more women's peak pressure will increase, pronation can increase compare with before. Supination movement increase, this focused pressure in lateral, also, supination increased more. If the supination movement increased, foot pressure focused in lateral, therefore, it is appeared force distribution in gait direction. This is bad movement in foot's stability. 3) Women's dress shoes in landing phase displayed a long time, this is when women's dress shoes wear, gait movement is unbalance, so, landing phase displayed a long time. For compensation in gait, swing phase quick movement. 4) Women's dress shoes displayed peak pressure distribution in lateral of rearfoot part, Sneakers shoes displayed peak pressure distribution in medial of forefoot part. Its results has good impact absorption compare with women's dress shoes. In forefoot part, sneakers shoes has good propulsive force compare with women's dress shoes.

• Journal of the Korean Society of Costume
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• v.57 no.10
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• pp.50-59
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• 2007

This study has been conducted to classify elderly men's feet with the three-dimensional body scanner data of Size Korea. It was intended to assist the manufacturing of the shoes that can appropriately perform the functions of feet, by providing the specific information about the shapes of elderly men's feet that are altered as a result of aging and shoe-wearing for a long time. The findings are as follows. 1. The investigations into the average and standard deviation of the measurements and index values for the elderly men's feet showed a large personal difference in the items of length and circumference. 2. The factors constituting the elderly men's feet were observed to be the size of foot width(Factor 1), the central angle of feet and the extension of toes(Factor 2), the size of ankle(Factor 3), the positions of lateral malleolus and pternion(Factor 4), and the position and size of medial malleolus(Factor 5). 3. The cluster analysis for the classification of elderly men's feet produced three types of them.

• Korean Journal of Applied Biomechanics
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• v.28 no.2
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• pp.135-141
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• 2018

Objective: The purpose of this study was to investigate the effect of functional ankle instability (FAI) and surgical treatment (ST) on postural stability and leg stiffness during vertical-drop landing. Method: A total of 21 men participated in this study (normal [NOR]: 7, FAI: 7, ST: 7). We estimated dimensionless leg stiffness as the ratio of the peak vertical ground reaction force and the change in stance-phase leg length. Leg length was calculated as the distance from the center of the pelvis to the center of pressure under the foot. Furthermore, the analyzed variables included the loading rate and the dynamic postural stability index (DPSI; medial-lateral [ML], anterior-posterior [AP], and vertical [V]) in the initial contact phase. Results: The dimensionless leg stiffness in the FAI group was higher than that of the NOR group and the ST group (p = .018). This result may be due to a smaller change in stance-phase leg length (p = .001). DPSI (ML, AP, and V) and loading rate did not show differences according to the types of ankle instability during drop landing (p > .05). Conclusion: This study suggested that the dimensionless leg stiffness was within the normal range in the ST group, whereas it was increased by the stiffness of the legs rather than the peak vertical force during vertical-drop landing in the FAI group. Identifying these potential differences may enable clinicians to assess ankle instability and design rehabilitation protocols specific for the impairment.

• Journal of Korean Foot and Ankle Society
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• v.9 no.2
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• pp.140-145
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• 2005

Purpose: To analyze the outcome of metatarsal lengthening of first brachymetatarsia by callotasis using an external fixator. Materials and Methods: Between January 1998 and February 2004, 10 patients (17 cases) were reviewed. The mean age at operation was 17.3 years. Seven patients had bilateral first brachymetatarsia and eight patients had combined 4th brachymetatarsia. The operations were performed with a monoexternal fixator, and distraction was started at a rate of 0.75 mm/day after 7 days. The radiographic results were evaluated by lengthening amount and percentage, fixation time, and healing index. Complications and AOFAS score were evaluated. Results: The average lengthening amount was 17.7 mm and the average lengthening percentage was 43.4%. The external fixation time was 107 days and average healing index was 69.8 days/cm. The evaluation according to AOFAS score was excellent in 12 cases and good in 5 cases. Complications were 4 cases of hallux valgus, 4 of metatarsophalangeal joint stiffness, 3 of medial angular deformity, 3 of pes cavus, 2 of pin breakage, 2 of pin site infection, and 1 of skin hyperpigmentation. Conclusion: Callotasis for 1st brachymetatarsia is a very useful treatment method with high patient satisfaction, excellent healing rate and early ambulation without bone graft. Nevertheless, great care must be taken to minimize the various possible complications.

• Journal of Korean Foot and Ankle Society
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• v.2 no.2
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• pp.76-81
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• 1998

Chiefly, painful heel syndrome is observed at old age. Many possible reasons were bursitis, plantar fasciitis, calcaneal periostitis around the calcaneus and achilles tendon. But the exact cause was not clearly identified due to complexity of subcalcaneal pain mechanism. The incidence of calcaneal spur and overweight were significant in painful heel syndrome. Our purpose of this study was analysis of underlyng cause and correlation about bony spur and overweight in painful heel syndrome. The author used incidence of heel spur on painful heel syndrome and body mass index to evaluate overweight. The material is 55 cases of painful heel syndrome patients and 60 cases of control group. Bony spur was one of the cause of painful heel syndrome. Body weight and calcaneal spur was developing factors on painful heel syndrome. And the result was as follows. 1. Spur formation incidence is 35 cases (63.6 %) in painful heel syndrome, 8 cases (13.3%) in normal control group. So, patient's group is significantly high (p<0.01). 2. Body mass index is 26.48 in painful heel syndromes, 21.75 in normal control groups. Overweight above index 27 is 22 cases (40%) in painful heel syndromes, 3 cases (5%) m normal control groups. So, patient's group is significantly high (p<0.01). 3. In painful heel syndrome, tenderness site is 46 cases (83.6%) in medial calcaneal tuberosity, 4 cases (7.3%) in central calcaneal tuberosity, 1 cases (1.8%) in both site. 4. Underlying causes of painful heel syndrome is 19 cases (34.5%) in plantar fasciitis, 16 cases (29.1%) in calcaneal periostitis, 11 cases (20%) in bursitis, 4 cases (7.3%) in tendinitis, 2 cases (3.6%) in entrapment neuropathy.

• Journal of Korean Foot and Ankle Society
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• v.12 no.1
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• pp.14-19
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• 2008

Purpose: We tried to understand the effects of the derotational closing wedge Akin osteotomy during the operation for the hallux valgus with pronation of great toe. Materials and Methods: Eighty five patients who had undergone Akin osteotomy among the eighty seven patients who had been treated with Scarf osteotomy with hallux valgus were included in this study. Derotational supination was added on the medial closing wedge Akin osteotomy at the base of proximal phalanx and it was secured with K-wire, headless screw or staple. We measured and analyzed pre- and post-operative hallux primus valgus angle and hallux pronational rotatory angle. Results: The hallux primus valgus angle improved an average of $14{\pm}2.98$ degrees to $-1{\pm}1.68$ degrees with the hallux pronational rotatory angle respectively from $24.8{\pm}7.64$ degrees to $4.7{\pm}4.22$ degrees. Conclusions: After the metatarsal osteotomy for the treatment of the hallux valgus with the pronation of great toe, derotational closing wedge Akin osteotomy can give us a belief that it can correct the hallux primus valgus angle and hallux pronational rotatory angle also and it can be a helpful method for minimizing the recurrence rate of the hallux valgus deformity.

• Journal of Korean Foot and Ankle Society
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• v.16 no.3
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• pp.169-174
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• 2012

Purpose: There are various methods proposed for the evaluation of the hindfoot alignment. However, due to structural calcaneus variances between patients, it is hard to assess this alignment definitively. Thus, this study proposes a new method for evaluating of the hindfoot alignment and its comparisons to the existing current methods. Materials and Methods: This study includes simple weight bearing hindfoot coronal view radiographs of 120 patients, taken between the time period of March 2008 to November 2009. Among the 120 patients, there was a 1:1 ratio of male to female with an average age of 40. The newly proposed method for evaluating this alignment is to draw a moment arm from the point where the sustentaculum tali meets the medial calcaneus border to the most prominent aspect of the lateral process of the calcaneal tuberosity. The angle produced via the intersection of this moment arm to the mid-longitudinal axis of the tibia is found and used to evaluate the hindfoot alignment. The inter and intra-observer reliability was evaluated using the coefficient of intraclass correlation. This study also investigates the comparisons between the newly proposed method to the traditionally used Saltzman et al hindfoot alignment evaluating technique. Results: The newly proposed method has higher inter and intra-observer reliability than the existing traditional Saltzman et al technique. Conclusion: This new method is recommended over the traditionally used Saltzman et al technique as it has a stronger confidence level and is appropriate for assessing hindfoot alignment in simple radiographs.

• Journal of Korean Foot and Ankle Society
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• v.27 no.4
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• pp.148-153
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• 2023

Traditionally, arthroscopic microfracture and autologous osteochondral autograft transplantation have been the primary surgical treatments for osteochondral lesions of the talus. On the other hand, recent advancements have introduced alternative approaches, such as autologous chondrocyte transplantation, matrix-derived autologous chondrocyte transplantation, intra-articular injection of concentrated bone marrow aspirate concentrate, and the use of fibrin glue to address chondral defects. Furthermore, some studies have explored a combination of bone marrow aspirate and matrix-derived chondrogenesis. In light of these developments, this report presents a case study of a young male patient in his early twenties with a relatively large osteochondral lesion exceeding 1.5 cm² on the medial talar dome. Instead of removing the osteochondral lesion, a surgical approach was employed to retain the lesion while addressing the unstable cartilage in the affected area. This approach involved a combination of bone marrow aspirate concentrate and matrix-derived chondrogenesis. The treatment yielded favorable clinical outcomes and ultimately successfully induced the bony union of osteochondral lesions. This paper reports the author's experience with this innovative approach with a review of the relevant literature.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2891-2894
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• 2003

This paper describes the possibility of analyzing gait pattern from the variation of the lower leg electrical impedance. This impedance is measured by the four-electrode method. Two current electrodes are applied to the thigh and foot., and two potential electrodes are applied to the lateral aspect. medial aspect, and posterior position of lower leg. We found the optimal electrode position for knee and ankle joint movements based on high correlation coefficient, least Interference, and maximum magnitude of impedance change. From such features of the lower leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.414-417
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• 2002

This paper describes the possibility of analyzing gait pattern from the variation of the lower leg electrical impedance. This impedance is measured by the four-electrode method. Two current electrodes are applied to the thigh and foot., and two potential electrodes are applied to the lateral aspect, medial aspect, and posterior position of lower leg. We found the optimal electrode position for knee and ankle joint movements based on high correlation coefficient, least interference, and maximum magnitude of impedance change. From such features of the lower leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level.