• 제목/요약/키워드: Heel Strike

검색결과 48건 처리시간 0.019초

대퇴골두 무혈성 괴사증에 있어서 괴사 영역의 위치와 천공방향의 변화에 따른 대퇴골두 괴사영역에서의 응력 변화 분석에 대한 생체역학적인 고찰 (A Biomechanical Analysis of Stress Transfer Behaviors Within the Necrotic Area of Femoral Head secondary to Changes in Core Placement Direction on Various Distributions of Necrotic Areas in the Osteonecrosis of the Femoral Head)

  • 임도형;이성재;김정성;신정욱;김용식
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1998년도 추계학술대회
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    • pp.157-158
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    • 1998
  • The purpose of this study was to test the hypothesis that even very small change of the cue direction in the treatment of the early osteonecrosis could affect the outcomes of operation. For this, the changes in stress transfer within the necrotic area of the femoral head were investigated under various directions and placements of the core utilizing finite element method. The loading of 3188N, which represents after-heel-strike, was imposed in cubic cosine pattern. All nodes on the most distal surface of the model were constrained in all directions. All materials included were assumed to have linear-elastic behavior. The result says that the critical stress, which causes collapse of the femoral head, was reduced when the core was oriented toward the posterior side of the femoral head regardless of location of the necrotic area. The same result was obtained either fibular bone grafting or cementation was adopted. As a consequence, the biomechanical study suggests that the core should be directed toward the loading point where the resultant force is applied to get more desirable treatment of the osteonecrosis of the femoral head in the early stage.

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내리막 달리기의 충격 쇼크와 신체 관절의 운동학적 특징 (Impact shock and kinematic characteristics of the lower extremity's joint during downhill running)

  • 류지선
    • 한국운동역학회지
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    • 제15권4호
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    • pp.117-129
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    • 2005
  • The purpose of this study was to characterize the impact shock wave and its attenuation, and the kinematic response of the lower extremity's joints to the impact shock during downhill running in which the lower extremity's extensor acts dominantly. For this study, fifteen subjects(mean age:$27.08{\pm}4.39$; mass:$76.30{\pm}6.60$; height:$177.25{\pm}4.11$) were required to run on the 0% grade treadmill and downhill grades of 7%, and 15% in random at speed of their preference. When the participant run, acceleration at the tibia and the sacrum and kinematic data of the lower extremity were collected for 20s so as to provide at least 5 strides for analysis at each grade. Peak impact accelerations were used to calculate shock attenuation between the tibia and sacrum in time domain at each grade. Fast Fourier transformation(FFT) and power spectral density(PSD) techniques were used to analyze impact shock factors and its attenuation in the frequency domain. Joint coordinate system technique was used to compute angular displacement of the ankle and knee joint in three dimension. The conclusions were drawn as fellows: 1. Peak impact accelerations of the tibia and sacrum in downhill run were greater than that of 0% grade run, but no significant between conditions. Peak shock of PSD resembled also in pattern of peak impact acceleration. The wave of impact shock attenuation between the tibia and sacrum decreased with increasing grade, but didn't find a significant difference between grade conditions. 2. Adduction/abduction, flexion/extention, and internal/external rotation of the ankle and knee joints at support phase between grade conditions didn't make much difference. 3. At grade of 7% and 15%, there were relationship between the knee of the flexion/extension movement and peak impact acceleration during heel strike and found also it in the ankle of plantar/dorsiflexion at grade of 15%.

달리기 속도 증가에 따른 성별 CoP (Center of Pressure)의 복잡성 패턴 (Complexity Pattern of Center of Pressure between Genders via Increasing Running Speed)

  • Ryu, Jiseon
    • 한국운동역학회지
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    • 제29권4호
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    • pp.247-254
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    • 2019
  • Objective: The goal of this study was to determine the center of pressure (CoP) complexity pattern in approximate entropy technique between genders at different conditions of running speed. Background: It is conducted to evaluate the complexity pattern of CoP in the increment of running speed to have insights to injury prediction, stability, and auxiliary aids for the foot. Method: Twenty men (age=22.3±1.5 yrs.; height=176.4±5.4 cm; body weight=73.9±8.2 kg) and Twenty women (age=20.8±1.2 yrs.; height=162.8±5.2 cm; body weight=55.0±6.3 kg) with heel strike pattern were recruited for the study. While they were running at 2.22, 3.33, 4.44 m/s speed on a treadmill (instrumented dual belt treadmills, USA) with a force plate, CoP data were collected for the 10 strides. The complexity pattern of the CoP was analyzed using the ApEn technique. Results: The ApEn of the medial-lateral and antero-posterior CoP in the increment of running speed showed significantly difference within genders (p<.05), but there were not statistically significant between genders at all conditions of running speed. Conclusion: Based on the results of this study, CoP complexity pattern in the increment of running speed was limited to be characterized between genders as an indicator to judge the potential injury and stability. Application: In future studies, it is needed to investigate the cause of change for complexity of CoP at various running speed related to this study.

기능적 전기자극 치료기를 이용한 중풍구두가 편마비 환자의 보행에 미치는 영향 (The Effects Where the Stroke Shoes Which Use Functional Electric Stimulation Goes Mad to Walking of the Hemiplegia)

  • 김정선;박지환
    • 대한정형도수물리치료학회지
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    • 제13권1호
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    • pp.36-43
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    • 2007
  • Purpose: An objective analysis and observations were to be done on hemiplegia patients that are wearing a walking support device, Stroke shoes. Their improvements in walking pace, the reduction of distance between the two knee joint, the increase of curve angle of the knee joint and their steps and the reduction of ankle joint upon swing phase were analyzed using a 20 walking analyzer. Methods: An examination was carried out to see the patients' communication skill and independent walking and then let them walk with the Stroke shoes on to get results before and after wearing it. Simi Reality Motion Systems GmbH (Germany, 2007) was used to analyze the results regarding knee joint and ankle joint angle changes of sagitta plane and coronal plane, stepping distances, distances between the knees and walking pace. Results: 1. The articulation angle of ankle joint during swing phase decreased and knee joint has shown a statistically significant increase in such value(p<0.05). 2. Only knee joint showed a significant increase in articulation angle during heel strike(p<0.05). 3. Knee joint showed a significant increase in articulation angle during toe off(p<0.05). 4. The distance between the two knees as well as their foot steps significantly decreased compared with when Stroke shoes were not worn(p<0.05). 5. Stroke shoes with FES have shown positive effects on the patients in improving their walking styles overall. (p<0.05). Conclusion: There was an improvement in rotation walking pattern by a reduction in the distance between the knees after wearing Stroke shoes with FES. Plantar flexion reduced that occurred in ankle joint during walking and flexion angle increased in knee joint, both of which improved foot drop which was a major problem in hemiplegia patients. Also it is believed that the device will have some positive influences on knee joint stiffening paralysis to aid in improving inefficient walking phases.

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달리기 시 발의 인체측정학적 변인과 운동역학적 변인의 관계 (The Relationship between Anthropometric Parameters of the Foot and Kinetic Variables during Running)

  • Lee, Young Seong;Ryu, Jiseon
    • 한국운동역학회지
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    • 제29권3호
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    • pp.173-183
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    • 2019
  • Objective: The aim of this study was to investigate the correlation coefficients between anthropometric parameters of the foot and kinetic variables during running. Method: This study was conducted on 21 healthy young adults (age: $24.8{\pm}2.1yes$, height: $177.2{\pm}5.8cm$, body mass: $73.3{\pm}7.3kg$, foot length: $256.5{\pm}12.3mm$) with normal foot type and heel strike running. To measure the anthropometric parameters, radiographs were taken on the frontal and sagittal planes, and determined the length and width of each segment and the navicular height. Barefoot running was performed at a preferred velocity ($3.0{\pm}0.2m/s$) and a fixed velocity (4.0 m/s) on treadmill (Bertec, USA) in order to measure the kinetic variables. The vertical impact peak force, the vertical active peak force, the braking peak force, the propulsion peak force, the vertical force at mid-stance (vertical ground reaction when the foot is fully landed in mid-stance or at the point where the weight was uniformly distributed on the foot) and the impact loading rate were calculated. Pearson's correlation coefficient was used to investigate the relationship between anthropometric variables and kinetical variables. The significance level was set to ${\alpha}=.05$. Results: At the preferred velocity running, the runner with longer forefoot had lower active force (r=-.448, p=.041) than the runner with short forefoot. At the fixed velocity, as the navicular height increases, the vertical force at full landing moment increases (r= .671, p= .001) and as the rearfoot length increases, the impact loading rate decreases (r=- .469, p= .032). Conclusion: There was a statistically significant difference in the length of fore-foot and rearfoot, and navicular height. Therefore it was conclude that anthropometric properties need to be considered in the foot study. It was expected that the relationship between anthropometric parameters and kinetical variables of foot during running can be used as scientific criteria and data in various fields including performance, injury and equipment development.

달리기 시 인솔의 굽힘 강성 증가에 따른 발목과 중족골 관절의 운동학적 변인 및 관절 협응에 미치는 영향 (The Effects on Kinematics and Joint Coordination of Ankle and MTP Joint as Bending Stiffness Increase of Shoes during Running)

  • Kim, Sungmin;Moon, Jeheon
    • 한국운동역학회지
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    • 제31권3호
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    • pp.205-213
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    • 2021
  • Objective: The aim of this study was to analyze body stability Joint coordination pattern though as bending stiffness of shoes during stance phase of running. Method: 47 male subjects (Age: 26.33 ± 2.11 years, Height: 177.32 ± 4.31 cm, Weight: 65.8 ± 3.87 kg) participated in this study. All subjects tested wearing the same type of running shoes by classifying bending stiffness (A shoes: 3.2~4.1 N, B shoes: 9.25~10.53 N, C shoes: 20.22~21.59 N). They ran 10 m at 3.3 m/s (SD ±3%) speed, and the speed was monitored by installing a speedometer at 3 m intervals between force plate, and the measured data were analyzed five times. During running, ankle joint, MTP joint, coupling angle, inclination angle (anterior-posterior, medial-lateral) was collected and analyzed. Vector coding methods were used to calculate vector angle of 2 joint couples during running: MTP-Ankle joint frontal plane. All analyses were performed with SPSS 21.0 and for repeated measured ANOVA and Post-hoc was Bonferroni. Results: Results indicated that there was an interaction between three shoes and phases for MTP (Metatarsalphalangeal) joint angle (p = .045), the phases in the three shoes showed difference with heel strike~impact peak (p1) (p = .000), impact peak~active peak (p2) (p = .002), from active peak to half the distance to take-off until take-off (p4) (p = .032) except for active peak~from active peak to half the distance to take-off (p3) (p = .155). ML IA (medial-lateral inclination angle) for C shoes was increased than other shoes. The coupling angle of ankle angle and MTP joint showed that there was significantly difference of p2 (p = .005), p4 (p = .045), and the characteristics of C shoes were that single-joint pattern (ankle-phase, MTP-phase) was shown in each phase. Conclusion: In conclusion, by wearing high bending stiffness shoes, their body instability was increased during running.

Shoes from Pinet to the Present

  • June, Swann
    • 한국복식학회:학술대회논문집
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    • 한국복식학회 2001년도 19th International Costume Association Congress
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    • pp.11-13
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    • 2001
  • For those unfamiliar with the shoe world, Pinet (1817-1897) was a contemporary of Worth, the great Parisian couturier. So I look at the glamour shoes and the world of haute couture, and indeed the development of the named designer. That is a concept we are all familiar with now. So it is not easy to comprehend the lack of names for the exquisite work before 1850. Straightway I have to say that the number of noted shoe designers is far fewer than famous dress designers, but I will introduce you to some of them, against the background of contemporary shoe fashions. Franc;ois Pinet was born in the provinces (probably Touraine) in 1817, two years after the end of the Napoleonic Wars. His father, an ex-soldier, settled to shoemaking, a comparatively clean and quiet trade. It had a tradition of literacy, interest in politics, and was known as the gentle craft, which attracted intelligent people. We should presume father would be helped by the family. It was usual for a child to begin by the age of 5-6, tying knots, sweeping up, running errands and gradually learning the job. His mother died 1827, and father 1830 when he was 13, and at the time when exports of French shoes were flooding world markets. He went to live with a master shoemaker, was not well treated, and three years later set out on the tour-de- France. He worked with masters in Tours and Nantes, where he was received as Compagnon Cordonnier Bottier du Devoir as Tourangeau-Ia rose dAmour (a name to prove most appropriate). He went on to Bordeaux, where at 19 he became president of the local branch. In 1841 he went to Paris, and in 1848, revolution year, as delegate for his corporation, he managed to persuade them not to go on strike. By now the shoemakers either ran or worked for huge warehouses, and boots had replaced shoes as the main fashion. In 1855 Pinet at the age of 38 set up his own factory, as the first machines (for sewing just the uppers) were appearing. In 1863 he moved to new ateliers and shop at Rue ParadisPoissoniere 44, employing 120 people on the premises and 700 outworkers. The English Womans Domestic Magazine in 1867 records changes in the boots: the soles are now wider, so that it is no longer necessary to walk on the uppers. There is interest in eastern Europe, the Polonaise boots with rosette of cord and tassels and Bottines Hongroises withtwo rows of buttons, much ornamented. It comments on short dresses, and recommends that the chaussure should correspond to the rest of the toilet. This could already be seen in Pinets boots: tassels and superb flower embroidery on the higher bootleg, which he showed in the Paris Exposition that year. I think his more slender and elegant Pinet heel was also patented then or 1868. I found little evidence for colour-matching: an English fashion plate of 1860 shows emerald green boots with a violetcoloured dress.

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대퇴골두 무혈성 괴사증의 수술적 기법 적용 후 괴사 망상골 내에서의 응력 변화 해석 (An Analysis of Stress Transfer Behaviors within the Necrotic Cancellous Bone following Surgical Procedures or the Management of the Osteonecrosis of the Femoral Head)

  • 정성;이성재
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 추계학술대회
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    • pp.245-248
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    • 1997
  • Operative interventions for the management of osteonecrosis of the femoral head (ONFH) include core drilling, with or without vascularized fibular bone grafting. Nevertheless, their clinical results have not been consistently satisfactory. Recently, a new surgical procedure that incorporates cementation with polymethylmethacrylate (PMMA) after core drilling has been tried clinically. In this study, a biomechanical analysis using a finite element method(FEM) was undertaken to evaluate surgical methods and their underlying surgical parameter. Our finite element models included five types. They were (1) normal model (Type I), (2) necrotic model (Type II), (3) core decompressed model (Type III). (4) fibular bone grafted model (Type IV), and (5) cemented with PMMA model (Type V). The geometric dimensions of the femur were based on digitized CT-scan data of a normal person. Various physiological loading conditions and surgical penetration depths by the core were used as mechanical variables to study their biomechanical contributions in stress transfer within the femoral head region. In addition. the peak von Mises stress(PVMS) within the necrotic cancellous bone of the femoral head was obtained. The fibular bone grafted method and cementation method provided optimal stress transfer behaviors. Here. substantial increase in the low stress level was observed when the penetration depth was extended to 0mm and 5mm from the subchondral region. Moreover, significant decrease in PVMS due to surgery was observed in the fibular bone grafted method and the cementation method when the penetration depths were extended up to 0 and 5mm from the subchondral region. The drop in PVMS was greater during toe-off than during heel-strike (57% vs. 28% in Type IV and 49% vs. 22% in Type V). Both the vascularized fibular bone grafting method (Type IV) and the new PMMA technique (Type V) appear to be very effective in providing good stress transfer and reducing the peak Von-Mises stress within the necrotic region. Overall results show that fibular bone grafting and cementation methods are quite similar. In light of above results, the new cementation method appears to be a promising surgical alternative or the treatment of ONFH. The use of PMMA for the core can be less prone to surgical complication as opposed to preparation of fibular bone graft and can achieve more immediate fixation between the core and the surrounding region.

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