• Journal of the Society of Naval Architects of Korea
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• v.50 no.4
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• pp.206-216
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• 2013

The present study considers the prediction of wind-induced heel of cruise ship and its stabilization. Wind load in ocean exerts on the surface of superstructure of cruise ship, which causes the heel moment on the ship. The calculation of wind load starts from choosing wind speed profile, so that the logarithmic wind profile model is applied in this study. Heel moment by wind load is calculated by adopting approximate formulation and applied to the ship motion analysis in time domain. Motion stabilizers, such as stabilizing fin and U-tube tank, are considered to reduce the heel effect as well as excessive roll motion. From this study, it is expected that the present method can be applied to the prediction and stabilization of the heel motion of cruise ships.

• The Journal of Korean Physical Therapy
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• v.33 no.1
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• pp.28-33
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• 2021

Purpose: This study examined the effects of heel raise exercises combined with neuromuscular electrical stimulation (NMES) on the muscle strength and postural control ability of subjects with functional ankle instability (FAI). Methods: Twenty-two subjects with FAI participated in this study. They were assigned randomly to two groups: 11 each in the NMES and the sham-NMES groups. Heel raise exercise was applied, and NMES electrodes were attached to the peroneus longus muscles. The NMES group applied NMES during the heel raise exercise. NMES was applied for 20 minutes during the heel raise exercise. The heel raise exercise was performed four times a week for five weeks. The muscle strength and balance error scoring system (BESS) were measured before and after the intervention. Results: A comparison of before and after the intervention within the groups revealed improved muscle strength in the NMES and Sham-NMES groups, but the BESS was improved under all conditions only in the NMES group. The Sham-NMES group showed no improvement in the unstable support surface. Furthermore, when comparing the amount of change before and after the intervention between the groups, there were significant differences in the total score and unstable support in the BESS and muscle strength. Conclusion: NMES had a positive effect on the functional activities of the functional ankle instability subjects, such as balancing on an unstable support surface during postural control and increasing muscle strength.

• Korean Journal of Applied Biomechanics
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• v.24 no.2
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• pp.151-160
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• 2014

The purpose of this study was to investigate the GRF(ground reaction force) parameters according to the shoes's heel heights and ground landing distances during downward stairs on bus. Participants selected as subject were consisted of young and healthy women(n=9, mean age: $21.30{\pm}0.48$ yrs, mean height: $164.00{\pm}3.05cm$, mean body mass: $55.04{\pm}4.41kg$, mean BMI: $20.47{\pm}1.76kg/m^2$, mean foot length: $238.00{\pm}5.37mm$). They were divided into 2-types of shoe's heel heights(0 cm/bare foot, 9 cm) and also were divides into downward stairs with 3 types of landing distance(20 cm, 35 cm, 50 cm). A one force-plate was used to collect the GRF(AMTI, USA) data from the sampling rate of 1000 Hz. The GRF parameters analyzed were consisted of the medial-lateral GRF, anterior-posterior GRF, vertical GRF, loading rate, Center of Pressure(${\Delta}COPx$, ${\Delta}COPy$, COP area) and Dynamic Postural Stability Index(MLSI, APSI, VSI, DPSI) during downward stairs on bus. Medial-lateral GRF and vertical GRF didn't show significant differences statistically according to the shoe's heel heights and landing distance, but 9 cm shoes heel showed higher vertical GRF than that of 0 cm bare foot in landing distance of 50 cm. Also anterior-posterior GRF didn't show significant difference statistically according to the shoe's heel heights, but landing distance of 20 cm showed higher than that of landing distances of 35 cm and 50 cm in anterior-posterior GRF. Loading rate didn't show significant difference statistically according to the landing distance, but 9 cm shoe's heel showed higher than that of 0 cm bare foot during downward stairs. The ${\Delta}COPy$ and COP area didn't show significant differences statistically according to the shoe's heel heights and landing distance, but 0 cm bare foot showed higher than that of 9 cm shoe's heel in ${\Delta}COPx$. Dynamic Postural Stability Index(MLSI, APSI, VSI, DPSI) didn't show significant differences statistically according to the landing distance, but 9 cm shoe's heel showed decreased value than that of 0 cm bare foot in dynamics balance. Considering the above, parameters of GRF showed different characteristics according to the shoe's heel heights and ground landing distances during downward stairs on bus.

• Journal of Korean Foot and Ankle Society
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• v.22 no.1
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• pp.21-25
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• 2018

Purpose: To analyze the correlation between a rupture of the hypovascular zone and early single heel raising after Achilles tendon repair. Materials and Methods: From January 2012 to August 2015, 68 patients, who underwent surgical treatment for a Achilles tendon rupture using Krackow method, were analyzed retrospectively. The patients were divided into two groups according to possibility of single heel raises within 3 months postoperatively. During the periodic outpatient observations, the visual analogue scale, Achilles tendon total rupture score (ATRS), and timing capable single heel raises were evaluated. In addition, the preoperative defect size and distance between the calcaneal osteotendinous junction and the rupture site were measured by ultrasound in all cases. Results: Twenty-three patients could perform a single heel raise within 3 months after surgery (early single heel raise group), and fortyfive patients could perform a single heel raise after 3 month postoperatively. The age, gender, body mass index, smoking, and operation delay were similar in the two groups. In addition, the defect size and distance between the calcaneal osteotendinous junction and rupture site as measured by preoperative ultrasound were similar (p=0.379 and p=0.631, respectively). On the other hand, when the rupture site was divided into the hypovascular zone (4~7 cm from calcaneal osteotendinous junction) and non-hypovascular zone, the hypovascular zone rupture rate was significantly lower in the early single heel raise group (60.9%, 14/23; 91.1%, 41/45; p=0.003). In logistic regression analysis, the odds of the hypovascular zone rupture group being capable of early single heel raise were 0.189 (p=0.017). The ATRS score at 3 months and 1 year after surgery were significantly higher in the early single heel raise group (p<0.001). Conclusion: Achilles tendon rupture at the hypovascular zone is a poor prognostic factor for early single heel raise and might affect the prognosis significantly after an Achilles tendon rupture operation.

• Physical Therapy Korea
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• v.6 no.2
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• pp.32-42
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• 1999

This study was conducted to identify the effects of high-heel shoes on EMG activities of rectus femoris and biceps femoris in 28 healthy women. Subjects were composed of experimental group (wearing high-heel shoes) and control group (wearing low-heel shoes). Two groups participated in three conditions standing (bare foot wearing athletic shoes and 7.5 cm height shoes). In high-heel shoes condition, EMG activities of rectus femoris of control group were significantly lower than that of biceps femoris of experimental group, but EMG activities of both muscles of experimental group did not should significant difference. In bare foot standing condition, EMG activities of rectus femoris of experimental group were significantly lower than that of biceps femoris but EMG activities of both muscles of control group had no significant difference. These results showed that hamstring lengthening effects was produced when wearing high-heel shoes because the external knee extension moment was increased. In the short term, high-heel shoes effect on the increase of the biceps femoris activities by spindle reflex, but in the long term, the normal amplitude of the same muscle activities by Golgi tendon organ reflex.

• Archives of Plastic Surgery
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• v.42 no.5
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• pp.619-625
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• 2015

Background The reconstruction of ankle and heel defects remains a significant problem for plastic surgeons. The following options exist for reconstructing such defects: local random flaps, reverse flow island flaps, and free flaps. However, each of these methods has certain drawbacks. Peroneal artery perforators have many advantages; in particular, they are predictable and reliable for ankle and heel reconstructions. In this study, we report our clinical experience with peroneal artery perforator-based pedicled flaps in ankle and heel reconstructions. Methods From July 2005 to October 2012, 12 patients underwent the reconstruction of soft tissue defects in the ankle and heel using a peroneal artery perforator-based pedicled flap. These 12 cases were classified according to the anatomical area involved. The cause of the wound, comorbidities, flap size, operative results, and complications were analyzed through retrospective chart review. Results The mean age of the patients was 52.4 years. The size of the flaps ranged from $5{\times}4$ to $20{\times}8cm^2$. The defects were classified into two groups based on whether they occurred in the Achilles tendon (n=9) or heel pad (n=3). In all 12 patients, complete flap survival was achieved without significant complications; however, two patients experienced minor wound dehiscence. Nevertheless, these wounds healed in response to subsequent debridement and conservative management. No patient had any functional deficits of the lower extremities. Conclusions Peroneal artery perforator-based pedicled flaps were found to be a useful option for the reconstruction of soft tissue defects of the ankle and heel.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.593-601
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• 2009

The goal of this study was to investigate the lower extremity's coordination determined by temporal relations with increasing high-heel (3, 7, 9cm) while walking on a treadmill. Twelve healthy women who walked on a treadmill under three conditionswearing 3cm high-heel shoes, 7cm, and 9cm-while kinematic data were collected using a six-cameras (240Hz) Qualisys ProReflex System. From these data, knee flexion, tibia internal rotation, and foot eversion were calculated in Euler technique and found the time for occurring the maximum angle of these movements. The maximum angle of these movements occurred almost simultaneously in 3cm high-heel walking, but not in 7cm and 9cm. The ratio of time for maximum angle of the foot eversion to tibia internal rotation converged to 1 in 3cm high-heel walking, but were less than 1 in 7cm and 9cm. In conclusion, it was indicated that 3cm high-heel walking had better the lower extremity's coordination compared with 7, 9cm high-heel walking.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1242-1246
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• 2016

Heel rocking phase in gait cycle is from initial contact to forefoot contact. The purpose of this study was to investigate the effect of age on heel rocking time. Seven young women ($21.9{\pm}1.5yrs$) and seven elderly women ($74.1{\pm}6.7yrs$) participated in this study. Subjects wore the shoes equipped with pressure sensors and walked along 10 m walkway at comfortable speeds. Stride time, stance time, and heel rocking time were compared between groups. Stride time was not different between groups (p=0.087). Stance time was longer (p<0.001) but heel rocking time was shorter in the elderly than in the young (p<0.001). The shorter heel-rocking time in elderly women indicates less efficient shock-absorption in the heel-rocking phase, which might be related to the abnormal control and/or reduced performance of ankle dorsiflexors.

• Journal of Korean Foot and Ankle Society
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• v.4 no.2
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• pp.55-60
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• 2000

Purpose: To investigate the effect of heel elevation on the radiographic parameters of the forefoot. Materials and Methods: Forty feet in twenty-one adults were studied. Weight bearing dorsoplantar radiograph was taken with the foot on a flat surface and with the heel of the foot elevated by 5cm. Various parameters were measured and compared between the results with and without heel elevation. Result: The hallux valgus angle was increased by $5.0{\pm}3.5$ degrees with heel elevation and the change was statistically significant(p<0.01). There was no statistically significant changes in the other parameters. Conclusion: The results of this study suggest that high-heeled shoes might contribute in causing or aggravating the degrees of the hallux valgus.

• Journal of The Korean Society of Integrative Medicine
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• v.4 no.1
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• pp.49-56
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• 2016

Purpose : The purpose of this study is to examine the effect of different heel heights on gait deviation and balance. Method : Participants were 16 women majoring in physical therapy in Kyungbuk college, located in Yeong-ju, North Kyungsang Province. Balance and gait patterns were measured by Good Balance and GAIT Rite. Result : Statistically significant differences were found in swing right measured by Gait-rite, and also in Analyze End, Ant-post, Med-Lat, and gait ability score(p < .05) regarding dynamic balance ability. Conclusion : There was no statistically significant difference in gait ability between those who walked barefoot and highheeled. However, balance ability was different "between them". This shows that heel height can lead to decrease in gait ability. Further research should include more participants and use a wide range of heel heights.