• 한국운동역학회지
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• 제18권1호
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• pp.169-178
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• 2008

본 연구는 계단 보행 중 연속적인 두 스텝의 3차원적 지면반력 파라미터를 제공하고, 계단의 너비에 따른 지면 반력 파라미터의 차이 및 비대칭성과 일관성을 규명하는데 있다. 10명의 성인 대상자가 본 실험에 참여하였으며, 각 10번의 평지, 상향 및 하향보행을 3가지의 다른 너비의 계단에서 실시하였다. 본 연구를 수행한 결과 다음과 같은 결론을 얻었다. 첫째, 계단의 너비는 대부분의 지면반력 파라미터들의 패턴이나 일관성, 비대칭지수에 영향을 미치지 않았다. 둘째, 평지 보행과 계단보행은 지면반력 파라미터의 패턴에서 큰 차이를 보였다. 평지보행과 상향보행은 Fz1, Fz2, 그리고 Fz3로 구성되는 "M" 형태를 보인 반면에 하향보행에서는 Fz2가 거의 없고 큰 Fz1과 작은 Fz3로 구성된 패턴을 보였다. 또한 계단 보행은 평지보행과 매우 다른 전 후 지면반력 패턴을 보였다. 즉 상향보행은 Fy1이 존재하지 않는 패턴을, 하향보행은 Fy2가 존재하나 매우 작은 크기를 보였다. 셋째, 계단보행의 수직 지면반력 파라미터들은 적용가능한 일관성 지수 및 비대칭 지수를 나타내었다.

• 한국운동역학회지
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• 제21권2호
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• pp.189-196
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• 2011

The purpose of this study was to verify the difference in biomechanical variation and pattern of the lower limb between planned and unexpected termination, which is related to the prevention of fatal fall in the elderly. Therefore, selected twenty subjects for each group which composed of females(age: $73.5{\pm}4.63$ year, height: $153.2{\pm}6.46$ cm, body mass: $58.98{\pm}5.82$ kg) and women(age: $23.4{\pm}2.5$ year, height: $164.65{\pm}3.9$ cm, body mass: $58.47{\pm}5.53$ kg) in their twenties. As a result, lower limb's extension moment and power were increased significantly in statistics(p<.05). Also, knee joint power showed instant changes from concentric contraction to eccentric contraction and hip joint power from eccentric contraction to concentric contraction. During unexpected termination there were dramatical increase in eccentric contraction and power(p<.05). In both planned and unexpected termination, ankle joint moment were higher in young group, but the moment of the hip joint were higher in the elderly group(p<.05). In contrast to younger group, there were no changes in knee extension moment in elderly group(p<.05). but showed relatively higher hip joint extension moment and power(p<.05).

• 대한의용생체공학회:의공학회지
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• 제15권4호
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• pp.429-438
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• 1994

An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate eleclromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocnemius m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher'stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical slimulator restored partially gait function in paraplegic patients.

• 한국정밀공학회지
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• 제22권7호
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• pp.112-121
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• 2005

This paper is concerned with smooth trajectory generation of biped robot which has inverted pendulum type balancing weight. Genetic algorithm is used to generate the trajectory of the leg and balancing weight. Balancing trajectory can be determined by solving the second order differential equation under the condition that the reference ZMP (Zero moment point) is settled. Reference ZMP effect on gait pattern absolutely but the problem is how to determine the reference ZMP. Genetic algorithm can find optimal solution under the high order nonlinear situation. Optimal trajectory is generated when use genetic algorithm which has some genes and a fitness function. In this paper, minimization of balancing joints motion is used for the fitness function and set the weight factor of the two balancing joints at the fitness function. Inverted pendulum type balancing weight is very similar with human and this model can be used fur humanoid robot. Simulation results show ZMP trajectory and the walking experiment made on the real biped robot IWR-IV.

• The Journal of Korean Physical Therapy
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• 제11권3호
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• pp.151-158
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• 1999

당뇨병성 신경병증은 환자의 자각증상이 없다하더라도 검사를 시행했을 시 신경전달속도가 떨어진다. 특히 감각신경과 자율신경의 손상이 지배적이다. 환자는 외부적인 압박에 대하여 감각이 둔하게 된다. 그로 인해 궤양이 생기고 보행과 자세조절에 문제가 생기게된다. 당뇨가 심하게 되면 환자는 가벼운 건드림조차도 통증으로 인지한다. 때로는 통증 때문에 잠을 잘 수 없기도 없다. 당뇨 치료법에는 인슐린요법, 식이요법 외에 운동치료가 당을 조절하는데 매우 효과적이다. 부가적으로 생기는 통증조절에는 경피전기신경자극이 적절하다. 앞으로의 당뇨환자들의 치료접근 중 물리치료 방법에 있어서, 궤양치료, 통증치료, 신경손상의 회복, 보행조절과 자세안정, 그리고 운동치료에 관한 더 많은 연구가 필요하다.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권8호
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• pp.506-509
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• 2003

This paper describes the possibility of analyzing gait pattern from the changes of the lower leg electrical impedance. This impedance was measured by the four-electrode method. Two current electrodes were applied to the thigh, knee, and foot., and two potential electrodes were applied to the lateral, medial, and posterior position of human leg. The correlation coefficients of the joint angle and the impedance change from human leg movement was obtained using a electrogoniometer and 4ch impedance measurement system developed in this study. 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. The correlation coefficients of the ankle, knee, and the hip movements were -0.913, 0.984 and 0.823, respectively. From such features of the human leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level. This system showed feasibility that lower leg movement could be easily measured by impedance measurement system with a few skin-electrodes.

• 한국운동역학회지
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• 제13권1호
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• pp.109-119
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• 2003

The purpose of this study was to investigate differences of the mechanical efficiency on the characteristics of the basketball wheelchairs(cambers & size of the handrims). Nine healthy and normal wheelchair basketball players who had no impairments to their upper extremities were volunteered to participate in this study. $VO_2$ was collected using automatic gas analyzer(vmax29). Gross efficiency, net efficiency and work efficiency were analyzed from the calculated external power output and energy expenditure. The results were followed. First, gross efficiency in the basketball wheelchairs was observed across the range from 4 to 10%. Gross efficiency in this study showed less values than that from the literature reviewed in the arm cranking(15%), racing wheelchair(above 30%), gait(27%) and cycling(18-23%). Second, the small size of handrim(61cm) at the 16 degrees of camber produced higher efficiency values than the large size of handrim(66cm) whereas the different sizes of handrim at the 20 degrees of camber did not show any pattern. Third, both faster speed($1.11^m/s{\rightarrow}1.39^m/s$) and increases in treadmill inclination produced increases in energy expenditure. The results of this study may provide not only better understanding of the mechanical efficiency with adequate camber degree and proper size of handrim but also fundamental information for manufacturing the wheelchair.

• 대한물리의학회지
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• 제3권3호
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• pp.177-183
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• 2008

Purpose : The purpose of this study was to investigate characteristics of the muscle activities during level walking and stairs ascending in young adults. Methods : Fifteen young adult were recruited this study. Muscle activity (BIOPAC System Inc., Santa Barbara, U.SA). Statistical analysis was difference between level and stair walking. Results : In stance phase, muscle activity of low extremity generally more increased during ramp ascent both young adults. In swing phase, muscle activity of low extremity generally more increased during stairs ascent in young adults. Conclusion : These results indicate that stair and ramp ascent is more difficult task than level walking in young adults. Muscle activity was more changed at ramp ascent. In the future, we suggest that studies of stair and ramp gait pattern regarding ambulatory patient with disabilities be further studied and an appropriate stairs and ramp inclination will be indicated.

• 대한통합의학회지
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• 제2권1호
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• pp.23-34
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• 2014

연구목적 : 본 연구의 목적은 8주간의 점진적인 속도증진 훈련이 뇌졸중환자의 족저압, 보행주기, 보행대칭성에 어떠한 영향을 주는지 알아보는 것이다. 연구방법 : 연구에 참여한 대상자들은 뇌졸중으로 진단 받고 N병원에 입원한 편마비환자 20명(실험군 10명, 대조군 10명)을 대상으로 하였다. 이들은 모두 물리치료와 작업치료를 받았고, 실험군은 주3회, 8주간의 트레드밀 보행훈련를 받았고, 대조군은 받지 않았다. 실험전, 후에 F-scan을 이용하여 보행주기, 보행대칭성을 검사하였다. 연구결과 : 8주 후, 보행주기는 실험군의 양하지지지기 I II, 단하지지지기에서 모두 유의하게 증가하였으나, 대조군에서는 양하지지지기 II, 단하지지지기에서 유의하게 증가하였다. 유각기는 실험군과 대조군 모두 유의하지는 않았다. 보행대칭성은 입각기 대칭성에서 대조군과 비교하여 실험군에서 유의하게 증가하였으나, 유각기 대칭성은 실험군과 대조군 모두 유의하지 않았다. 결론 : 뇌졸중 환자에 있어 보행훈련은 보행주기과 보행대칭성과 를 개선시키며, 특히 점진적인 속도 증진훈련은 양하지지지기, 단하지지지기, 입각기 보행대칭성에 효과적인 방법으로 사용될 수 있을 것으로 보인다.

• Journal of Yeungnam Medical Science
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• 제23권1호
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• pp.118-123
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• 2006

Dentatorubropallidoluysian atrophy (DRPLA) is a rare neurodegenerative disorder usually inherited in an autosomal dominant pattern. DRPLA has been shown to be associated with expansion of an unstable cytosine-adenine-guanine (CAG) trinucleotide repeat in a gene on chromosome 12p. We evaluated a family with DRPLA that affected three members; A 35-year-old female presented with seven year history of gait ataxia, dysarthria and mild cognitive impairment. The MRI of the brain revealed diffuse cerebellar atrophy with an incidental lipoma in the midbrain. Her 30-year-old brother presented with progressive cerebellar ataxia that developed at the age of 20. Her grandmother and mother were reported to have developed ataxia during the late period of their life, and died at the age of 60 and 55, respectively. The demonstration of an expanded CAG repeat in the gene for DRPLA was used to confirm the diagnosis.