• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.792-795
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• 2007

To quantify irregular body motions the time series analysis was applied to the gait study. The motions obtained from gait experiment are complex to exhibit nonlinear behaviors. The purpose of this study is to measure quantitatively the characteristics of the major six joints of the body during walking. The gait experiments were carried out for eighteen young males walking on a motor driven treadmill. Joint motions were captured using eight video cameras, and then three dimensional kinematics of the neck and the upper and lower extremities were computed by KWON 3D motion analysis software. The largest Lyapunov exponent was calculated from the time series to quantify stabilities of each joint. The results provides a data set of nonlinear dynamic characteristics for six joints engaged in normal walking.

• 대한물리치료과학회지
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• 제7권1호
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• pp.285-294
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• 2000

80 persons who don't have past history of cardiopulmonary and neuromuscular disease. The results were as follow; 1. PCI(Physiological Cost Index) value without loading to ankle were significantly increased compared to 1kg, and 2kg (p<0.01). 2. Female Subjects showed more increased PCI value in without loading and lkg, 2kg loading compared to male subjects (p<0.01). 3. In every PCI condition the difference among height groups was observed (p<0.01). 4. The difference among weight groups in each PCI condition was observed (p<0.01). These results showed that energy consumption was increased according to loading on the ankle during gait so weight of orthosis or prosthesis must be considered when choosing them and during gait training with these ones.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1994년도 춘계학술대회논문집
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• pp.136-144
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• 1994

In this study, the human gait trajectories during normal walking were synthesized using the inverse kinematics and optimization techniques. The synthesis based on a lower extremity model consisting of a torso and two legs. Each leg has three segments: thigh, shank, foot, and is assumed to move with six degrees-of-freedom. In order to synthesize trajectiories of this redundant system, the sum of angular displacements of articulating joints was selected as an objective function to be minimized. The proposed algorithm in this study is very useful for the analysis of human gait. For the gait analysis, the trajectories of four points in each leg should be measured. However, by using the algorithm, measuring the trajectories of two points is sufficient, and thus the experimental set-up can be simplified. The predicted joint trajectories showed a good agreement with those obtained from the experiment. The statistical analysis and graphic simula- tions are also presented.

• 전기학회논문지
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• 제58권5호
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• pp.1010-1018
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• 2009

An inertial navigation system for pedestrian position tracking is proposed, where the position is computed using inertial sensors mounted on shoes. Inertial navigation system(INS) errors increase with time due to inertial sensor errors, and therefore it needs to reset errors frequently. During normal walking, there is an almost periodic zero velocity instance when a foot touches the floor. Using this fact, estimation errors are reduced and this method is called the zero velocity updating algorithm. When implementing this zero velocity updating algorithm, it is important to know when is the zero velocity interval. The gait states are modeled as a Markov process and each state is estimated using the hidden Markov model smoother. With this gait estimation, the zero or nearly zero velocity interval is more accurately estimated, which helps to reduce the position estimation error.

• 한국임상수의학회지
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• 제20권4호
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• pp.504-507
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• 2003

Force plate analysis was used to describe the effect of acupuncture on right knee osteoarthritis (OA) in a seven-year-old hound breed dog weighing 27 kg. The acupuncture treatment was performed twice a week for 3 weeks. Ground reaction forces (GRFs) and subjective clinical scores in both hind limbs were obtained prior to and 72 hours after each treatment. Right vertical peak force was increased as the dog was acupunctured. Although their sensitivity was lower than that of the GRF data, the subjective clinical scores reflected an improvement. In addition, vertical peak force of normal left hind limb was also increased during this trial. These results indicate that gait analysis may be valuable objective method in future evaluation of acupuncture for OA of the stifle joint.

• Archives of Plastic Surgery
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• 제46권3호
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• pp.267-271
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• 2019

A 70-year-old man complained imbalance while walking, inability to perform ankle flexion, and could not stand on tip-toe 3 months after injury. The ankle looked swollen with loss of Achilles contour and obvious gait disturbance. Magnetic resonance imaging shows a 5-cm Achilles tendon gap. Subsequently, surgery was performed to solve the neglected Achilles tendon rupture. Patient was put under general anesthesia with a regional block. Using a nontourniquet technique, a reconstructive procedure was performed using a half-width autologous Achilles tendon graft, which was attached to the calcaneal prominence with wire in a double strand Bunnell fashion. As for the proximal stump, double core Bunnell/modified Kessler suturing was carried out to suture the graft to Achilles stump. To increase the vascularization, an ipsilateral gastrocnemius fascial flap with a distally based-pedicle was harvested to wrap around the tendon graft. At a 6-month follow-up, the patient was able to stand on tip-toe and had also regained a normal gait.

• 한국전문물리치료학회지
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• 제20권1호
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• pp.64-73
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• 2013

The purposes of this study were to develop a new orthosis controlling ankle and knee joint motion during the gait cycle and to identify the effects of the newly designed orthosis on gait kinematics and tempospatial parameters, including coordination of the extremities in stroke patients. Fifteen individuals who had sustained a stroke, onset was 16 months, participated in this study. Before application of the measurement equipment the subjects were accustomed to walking on the ankle-foot orthosis (AFO) or stance control knee with knee flexion assisted-oil damper ankle-foot orthosis (SCKAFO) for 5 minutes. Fifteen patients were investigated for 45 days with a 3-day interval between sessions. Measurements were walking in fifteen stroke with hemiparesis on the 3D motion analysis system. Comparison of AFO and SCKAFO are gait pattern. The difference between the AFO and SCKAFO conditions was significant in the gait velocity, step length of the right affected side, stance time of both legs, step-length asymmetry ratio, single-support-time asymmetry ratio, ${\phi}$-thigh angle and ${\phi}$-shank angle in the mid swing (p<.001). Using a SCKAFO in stroke patients has shown similar to normal walking speeds can be attained for walking efficiency and is therefore desirable. In this study, the support time of the affected leg with the SCKAFO was longer than with the AFO and the asymmetry ratio of single support time decreased by more than with the AFO. This indicates that the SCKAFO was effective for improving gait symmetry, single-support-time symmetry. This may be due to the decrease of gait asymmetry. Thus, the newly designed SCKAFO may be useful for promoting gait performance by improving the coordination of the extremity and decreasing gait asymmetry in chronic stroke patients.

• 한국운동역학회지
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• 제17권4호
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• pp.191-200
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• 2007

The purpose of this study was to analyze the foot-pressure distribution of trekking boots for assessing their functionality. Subjects participated in this study included 10 university male students who had no injury experience in lower limbs and a normal gait pattern. The size of all subjects was 270mm. Five models of trekking boots, most popular in Korea (A, B, C, D & E company), were selected for the test. Using the PEDAR-X system and PEDAR-X insoles, 5 different walking stages were analyzed for the foot-pressure distribution: (a) straight gait; (b) $45^{\circ}$ turn gait; (c) $25^{\circ}$ uphill gait; and (d) $25^{\circ}$ downhill gait. Results of the foot-pressure distribution and functionality on each stage were as follow; 1. Straight gait - In case of Max ground reaction force, mean plantar pressure and Max plantar pressure, there was not a distinct tendency; however, products manufactured by E and A company showed relatively lower pressure distribution. 2. $45^{\circ}$ turn gait - In Max ground reaction force, mean plantar pressure and Max plantar pressure, there wasn't a distinct tendency; however, products manufactured by E and A company showed relatively lower pressure distribution. Results also revealed that the products manufactured by E and A company were superior to those by other companies in terms of functionality. 3. $25^{\circ}$ uphill gait - In Max ground reaction force, mean plantar pressure and Max plantar pressure, there wasn't a distinct tendency; however, products manufactured by E and C company showed relatively lower pressure distribution. Results also revealed that the products manufactured by E and C company were superior to those by other companies in terms of functionality. 4. $25^{\circ}$ downhill gait - In Max ground reaction force, Mean plantar pressure and Max plantar pressure, there wasn't a distinct tendency; however, products manufactured by E company showed relatively lower pressure distribution. Results also revealed that the products manufactured by E company were superior to those by other companies in terms of functionality. Overall, five pairs of trekking shoes selected in this study showed the excellent performance in several conditions. The findings above may provide us with the important criteria for choosing trekking boots.

• The Journal of Korean Physical Therapy
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• 제10권1호
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• pp.127-138
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• 1998

This study was carried out tn invstigate and compare biomechanical characteristics during free speed gait in hemiplegic patients after stroke who took therapeutic exercise by analyzing kinematic and kinetic data in the sagital plane and electromyographic data. Six patients($41\~69$ years old) and age-matched six volunteers in good health(51-61 years old) wire studied. The patients were sorted into two groups, depending on their self-speed of walking : fast speed group(3 patients) and slow speed group(3 patients). The results were as fellows. : 1. In spatio-temparal parameters, affected and unaffected side of fast group showed symetry but blew group showed asymetry of single limb support, opposite foot contact and stance phase (p<0.05). Compared with normal group, patient group showed slower velocity, shoter stride length and longer double limb support (p<0.05). 2. In the pelvic anterior tilt, patient group showed lower valued than normal group. It. In the ground reaction force-vertical force, fast group showed similar double peak gragh compared with normal group, butvslow group showed lower values without double peak (p<0.05).

• 대한인간공학회지
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• 제26권1호
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• pp.19-27
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• 2007

Despite the widespread use of laterally wedged insoles for patients with knee osteoarthritis and medially wedged insoles for controlling rearfoot pronation, an understanding of the effects of wedged insoles was limited and sometimes controversial. The objective of this study was to evaluate the effect of wedged insoles on the kinematics and kinetics of normal gait. Ten male subjects without history of lower limb disorders were recruited. Each subject performed four gait cycles under each of seven conditions; shod with 5$^{\circ}$, 8$^{\circ}$ and 15$^{\circ}$, 8$^{\circ}$ and 15$^{\circ}$ laterally wedged insoles. In order to determine statistical differences among seven conditions, the measured temporal spatial variables, angular displacements, joint moments, and ground reaction forces were compared with a one-way analysis of variance. Some significant changes induced by wedged insoles were apparent in joint moments and ground reaction forces. The medially wedged insole increased the laterally directed ground reaction force and varus moments at the ankle force and varus moments at the ankle and the knee.