• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.75-84
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• 2013

In this study, the patterns and characteristics according to gait cycle were analyzed using to EMG signals during walking, and analyzed in the time domain and frequency domain. The experiments was performed divide to level-ground walking and stair walking, and gait cycle was analysis by stance and swing. In the sagittal plane by using the tilt sensor measures the angle of the lower leg, and EMG was measured from the quadriceps and biceps femoris. The tilt of the lower leg was showed the biggest tilt at HS, and showed lowest value at TO. All in walking according to the gait cycle IEMG showed a specific pattern, and is expected useful to determine the gait cycle and kind. In the frequency domain analysis was using STFT on able to frequency analysis according to time, and using the tilt sensor was identify gait cycle. We analyzed also spectrum of the results of the STFT in all gait types, and recognized that stance had broad bandwidth than that of swing. Through this study, it was confirmed the possibility of judgment and analysis of the gait cycle using EMG and the tilt in the sagittal plane of the lower leg. When used it, can improve the quality of life of amputation patients

• Journal of the Ergonomics Society of Korea
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• v.25 no.1
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• pp.43-49
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• 2006

A laboratory study was conducted to evaluate if two different age groups(young vs. old) had differences in walking velocity and heel contact velocity and, furthermore, if these gait characteristics could adversely influence initial friction demand characteristics(i.e. RCOF) and the likelihood of slip-initiation. Twenty eight(14 younger and 14 older adults) participated in the study. While wearing a safety harness, all participants walked at their preferred gait speed for approximately 20 minutes on the linear walking track(1.5m× 20m) consisting of two floor-mounted forced plates. During subsequent 20 cameras, respectively. The results indicated that older adults walked slower(i.e., slower whole body center-of-mass velocity), exhibited lower heel contact velocity, and produced lower initial friction demand characteristics (i.e. RCOF) in comparison to younger adults. However, ANCOVA indicated that the diferences in heel contact velocity between the two age groups were due to the effects of walking velocity. The bivariate analysis further suggested that walking velocity was correlated to RCOF and heel contact velocity, while heel contact velocity was not found to be correlated to RCOF. In conclusion, could be a better indicator for predicting initial friction demand characteristics(i.e. RCOF) not hel contact velocity.

• Korean Journal of Applied Biomechanics
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• v.25 no.3
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• pp.241-248
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• 2015

Objective : The purpose of this study was to investigate the theta on the components of ground reaction force according to the ground conditions during gait. Method : Six healthy women(mean age: 22 yrs, mean height: $166.14{\pm}2.51cm$, mean body weights: $56.61{\pm}4.58kg$) participated in this study. The medial-lateral GRF(Fx 1), anterior-posterior GRF(Fy 1, Fy 2), vertical GRF(Fz 1, Fz 2, Fz 3), and impact loading rate were determined from time function and frequency domain. Also, GRF theta were time function and forces. Results : Fx 1, Fy 1 and Fy 2 of stair descending showed significant statistically higher forces than that of level walking, and ascending. Fz 1 of stairs descending showed significant statistically higher forces than that of level walking and stairs ascending(theta $88.62^{\circ}$). Also, Fz 2 of level walking showed significant statistically higher forces than that of stairs ascending and descending(theta $65.78^{\circ}$). Fz 3 of stairs ascending showed significant statistically higher forces than that of level walking and stairs descending($65.26^{\circ}$). Impact loading rate of stairs descending showed significant statistically higher forces than that of level and ascending walking. The GRF showed similar correlation with GRF theta(r=.603) according to the ground conditions during gait. Conclusion : These results suggest that the GRF theta can be used in conjunction with a gait characteristics, prediction of loading rate and dynamic stability.

• Physical Therapy Korea
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• v.9 no.3
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• pp.47-65
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• 2002

This study examined the correlations among the Berg Balance Scale, which is a clinical tool used to evaluate balance ability, spatiotemporal parameters of gait, and falling; determined the parameters most closely related to falling; and identified a discriminatory parameter and its predictability. Thirty-four subjects aged 72 to 92 years participated in this study. Following a questionnaire survey about falling, the Berg Balance Scale and spatiotemporal parameters of gait were measured. The results revealed that the incidence of falls increased with aging and an accompanying reduction in the flexion range of motion of the hip joint. The gait characteristics of elderly people who fell easily included a slower walking speed, shorter stride, and longer stance time than other elderly. When the cutoff score was set at 45, the Berg Balance Scale was able to identify correctly those individuals who truly have experience of falling than when the cutoff score was set at 39. But when the cutoff score was set at 39, the scale's specificity identifying correctly those individuals who truly have not experience of falling was higher than at the cutoff score of 45. Therefore, the Berg Balance Scale is an appropriate screening method in a clinical setting for the early detection of elderly people at risk of falling. In conclusion, elderly people with a Berg Balance Scale score. below 45 are the most likely to fall owing to their decreased balance ability.

• Korean Journal of Applied Biomechanics
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• v.29 no.1
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• pp.23-32
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• 2019

Objective: The aim of this study was to provide kinematic data on the characteristics of spinal disease patients by comparing and analyzing kinematic variables related to foot balance and gait pattern of spinal disease. Method: The subjects of the study included 40 adult men and 60 adult women who visited the hospital in Busan. Patients who were diagnosed with spinal disease by a physician through X-ray examination were selected as subjects for the diagnosis of vertebral disc herniation, spinal stenosis, spinal disease diagnosed with spinal disease and the general public. Left and right foot pressure and contact area were checked by Gaitview pro meter. X-ray photographs were taken with a Zen-2090 mobile fluoroscopy under physicians' direct participation. One-way ANOVA was performed to compare the differences between the kinematic variables and post-hoc was performed by the Duncan method. Results: The difference in contact area between the left foot and the right foot was $115.30{\pm}14.15cm^2$ in the left side and $124.25{\pm}13.65cm^2$ in the left side in the spinal disease patients. The difference in pressure between the left and right side of the spinal disease patients was wider than that of the general people. Especially, the right side of the spinal disease patients showed a larger area of left foot contact than the general population. Conclusion: Spinal disease patients have wider contact area of the left foot than those of the general population. In the case of right spinal disease, the left foot support area is widened due to pain. In the gait, women showed slightly more posterior body center than men, and the upper body muscle imbalance and immobilization due to the spinal disease caused imbalance of the muscles moving to the lower limb, It was analyzed to inhibit movement.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.108.3-108
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• 2002

$\textbullet$ Introduction $\textbullet$ trend of walking robot $\textbullet$ Characteristics of waist-jointed walking robot $\textbullet$ simulation $\textbullet$ conclusion

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.4
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• pp.685-694
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• 2001

In this study, a transfemoral prosthesis system of which both stance phase and swing phase are controllable has been developed for the recovery of the biomechanical function of the amputated leg. It consists of a 5 bar link mechanism, a hydraulic-rubber knee damper for stance phase control and a pneumatic cylinder controlled via a microprocessor for stance phase control. The mechanical characteristics of the knee damper which absorbs the impact energy generated at the heel contact were investigated. The characteristics of the pneumatic cylinder essential for the speed adaptation of the prosthesis during swing phase were also studied for its mechanical characteristics. The prosthesis was subject to the clinical tests, and the gait characteristics obtained were very close to those of normal subjects. The stance and swing controlled prosthesis that were developed in this study showed good stability during the stance phase and showed good controllability during the swing phase.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.504-509
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• 2000

In this study, a transfemoral prosthesis system of which stance phase and swing phase are controlled during walking has been developed for the recovery of the biomechanical function of the amputated leg. It consists of a 5 bar link mechanism, a hydraulic-rubber knee damper for stance phase control and a pneumatic cylinder controlled via a microprocessor for stance phase control. The mechanical characteristics and behaviour of the knee damper which absorbs the impact energy generated at the heel contact was investigated. The characteristics of the pneumatic cylinder essential for the speed adaptation of the prosthesis during swing phase was also studied for its mechanical characteristics. The prosthesis was subject to the clinical test ant the gait characteristics obtained were very close to those of normal. The stance and swing controlled prosthesis that were developed in this study showed good stability during the stance phase and showed good controllability during the swing phase.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.7
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• pp.479-490
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• 2014

A lower extremity exoskeleton is a robot device that attaches to the lower limbs of the human body to augment or assist with the walking ability of the wearer. In order to improve the wearer's walking ability, the robot senses the wearer's walking locomotion and classifies it into a gait-phase state, after which it drives the appropriate robot motions for each state using its actuators. This paper presents a method by which the robot senses the wearer's locomotion along with a novel classification algorithm which classifies the sensed data as a gait-phase state. The robot determines its control mode using this gait-phase information. If erroneous information is delivered, the robot will fail to improve the walking ability or will bring some discomfort to the wearer. Therefore, it is necessary for the algorithm constantly to classify the correct gait-phase information. However, our device for sensing a human's locomotion has very sensitive characteristics sufficient for it to detect small movements. With only simple logic like a threshold-based classification, it is difficult to deliver the correct information continually. In order to overcome this and provide correct information in a timely manner, a probabilistic gait-phase classification algorithm is proposed. Experimental results demonstrate that the proposed algorithm offers excellent accuracy.

• Physical Therapy Korea
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• v.27 no.3
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• pp.178-184
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• 2020

Background: Stroke patients have reduced trunk control compared to normal people. The ability to control the trunk of a stroke patient is important for gait and balance. However, there is still a lack of research methods for the characteristics of stroke control in stroke patients. Objects: The aim of this research was to determine whether trunk position sense has any relation with balance and gait. Methods: This study assessed trunk performance by measuring position sense. Trunk position sense was assessed using the David back concept to determine trunk repositioning error in 20 stroke patients and 20 healthy subjects. Four trunk movements (flexion, extension, lateral flexion, rotation) were tested for repositioning error and the measurement was carried out 6 times per move; these parameters were used to compare the mean values obtained. Subjects with stroke were also evaluated with clinical measures of balance and gait. Results: There were significant differences in trunk repositioning error between the stroke group and the control group in flexion, lateral flexion to the affected side, lateral flexion to the unaffected side, rotation to the affected side, and rotation to the unaffected side. Mean flexion error: post-stroke: 7.95 ± 6.76 degrees, control: 3.32 ± 2.27; mean lateral flexion error to the affected side: 6.13 ± 3.79, to the unaffected side: 5.32 ± 3.15, control: 3.57 ± 1.92; mean rotation error to the affected side: 8.25 ± 3.09, to the unaffected side: 9.24 ± 3.94, control: 5.41 ± 1.82. There was an only significant negative correlation between the repositioning error of lateral flexion and the Berg balance scale score to the affected side (-0.483) and to the unaffected side (-0.497). A strong correlation between balance and gait was found. Conclusion: The results of this study indicate that stroke patients exhibit greater trunk repositioning error than age-matched controls on all planes of movement except for extension. And lateral flexion has correlation with balance and gait.