• Journal of Biomedical Engineering Research
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• v.19 no.5
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• pp.519-530
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• 1998

In this paper, the basic study on the design of the flexible keel of the energy-storage prosthetic foot was performed in order to Improve the walking performance and Increase the activities of the below knee amputees. Based on the analysis of the anthropometric data and the normal gait on two dimensional sagittal plane available In the literature, we presented a model of the basic structure of the flexible keel of the prosthetic foot. The model of the basic structure was composed of the simple beams, and linear rotational spring and damper. Laminated carbon fiber-reinforced composites were selected as the material of the basic structure model of the flexible keel In order to apply the high strength and light weight materials to the basic structure of the flexible keel of the prosthetic foot. The recoverable strain energy In response to the change of beam shape was calculated bur the finite element analysis and it was suggested that the change of beam shape could be the design variable in flexible keel design. The simulation process was systematically designed by using orthogonal array table in order to design the flexible keel structure which could store the more recoverable strain energy. finite element analysis was carried but according to the design of simulations by using the finite element program ABAQUS and the flexible keel structure of the energy-storage prosthetic foot was obtained from the analysis of variance(ANOVA). The dynamic simulation model of the prosthetic walking using the flexible keel structure was made and the dynamic analysis was carried but during one walk cycle. Based on the above results, an effective design process was presented for the development of the prosthetic fool system.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.105-115
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• 2006

The purpose of this study is to elucidate the mechanical characteristics of lower extremity joint movements at different walking speeds in obese people and suggest the very suitable exercise for obese person's own body weight and basic data for clinical application leading to medical treatment of obesity. This experimental subjects are all males between the ages of 20 and 30, who are classified into two groups according to Body Mass Index(BMI): one group is 15 people with normal body weight and the other 15 obese people. Walking speed is analysed at 3 different speeds ($1.5^m/s$, $1.8^m/s$, $2.1^m/s$) which is increased by $0.3^m/s$ from the standard speed of $1.5^m/s$. We calculated joint moments of lower extremity during stance phase through video recording and platform force measurement.Two-way ANOVA(Analysis of Variance, Mix) is applied to get the difference of moments according to walking speeds between normal and obese groups. Pearson's Correlation Analysis is applied to look into correlation between walking speeds and joint moments in both groups. Significance level of each experiment is set as ${\alpha}=.05$. As walking speed increases maximum ankle plantar flexion moment in the stance phase is smaller in obese group than in normal group, which is suggestive of weak toe push-off during terminal stance in obese group, and the highest maximum ankle plantar flexion moment in obese group during the middle speed walking($1.8^m/s.$). Maximum ankle dorsal flexion moment in obese group is relatively higher than in normal group and this is regarded as a kind of compensatory mechanism to decrease the impact on ankle when heel contacts the floor. Maximum knee flexion and extension moments are both higher in normal group with an increase tendency proportional to walking speed and maximum hip flexion and extension moments higher in obese group. In summary, maximum ankle plantar flexion moment between groups(p<.025), maximum knee moment not in flexion but in extension(p<.001) within each group according to increasing walking speed, and maximum hip flexion and extension moment(p<.001 and p<.004, respectively according to increasing walking speed are statistically significant but knee and hip moments between groups are not. Pearson correlation are different: high correlation coefficients in maximum knee flexion and extension moments, in maximum hip extension moment but not hip flexion, and in maximum ankle dorsal flexion moment but not ankle plantar flexion, in each group. We suspect that equilibrium imbalance develops when the subject increases walking speed and the time is around which he takes his foot off the floor.

• Korean Journal of Acupuncture
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• v.21 no.1
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• pp.113-127
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• 2004

Objectives : The usage of acupuncture has gained popularity as an alternative method of treatment for certain chronic pain conditions. However, the efficacy of acupuncture in various diseases has not been fully established and the underlying mechanism is not clearly understood. In the present study, the effect of electroacupuncture (EA) applied to foot samli$(ST_{36})$ on the carrageenan-induced knee arthritic pain was examined. Methods : A common source of persistent pain in humans is the knee arthritis. Knee arthritis was induced by injection of 2 % carrageenan $50\;{\mu}l$ into the knee joint cavity. When rats developed pain behaviors, EA was applied for 30 min. under enflurane anesthesia with repeated train stimuli at the intensity of 10X of muscle twitch threshold. The weight bearing force of the hind limb was measured for an indicator of pain level after each manipulation. Results : The average weight borne by the hind limb during normal gait was 55% of total body weight, which was reduced to less than 10% after knee arthritis. EA improved the weight bearing of the arthritic hind limb significantly for the duration of 4 hr. EA applied to $ST_{36}$ point produced a significant improvement of stepping force of the arthritic foot lasting for at least 4 h. However, $GB_{31}$ point did not produce any significant increase of weight bearing force. The analgesic effect was specific to the acupuncture point since the analgesic effect on the knee arthritis model could not be mimicked by EA applied to a nearby point, $GB_{31}$. The relations between EA-induced analgesia and endogenous nitric oxide(NO) and inducible NO synthase(iNOS)/neuronal NOS was also examined. Results were turned out that both NO production and nNOS/iNOS protein expression which is increased by arthritis were suppressed by EA stimulation applied to $ST_{36}$ point. Conclusions : The data suggest 1) that EA produces a potent analgesic effect on the rat model of chronic knee arthritis pain in a point specific manner and 2) that EA-induced analgesia modulate endogenous NO through the suppression of nNOS/iNOS protein expression.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.2
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• pp.199-209
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• 2020

Purpose : This study used a sarcopenia diagnostic algorithm proposed by the Asia working group in adults over 50 to diagnose sarcopenia and analyze body function. The purpose of this study is to prepare basic data for the management and prevention of sarcopenia. Methods : We performed a diagnostic evaluation of sarcopenia in 97 adults over the age of 50 years with the cooperation of the Seongnam senior experience complex in Seongnam-si, Gyeonggi-do. As a result of the diagnostic process, 24 subjects were placed into the sarcopenia group, while 73 subjects were placed into the normal group. We measured each subject's body, performed the timed up and go test to evaluate functional mobility, and conducted a questionnaire on the pre-symptom of locomotive syndrome and locomotive syndrome. Results : There were statistically significant differences in height, weight, and skeletal muscle mass between the two groups. There was also a statistically significant difference in the timed up and go test, which confirmed the difference in functional mobility between the two groups. In addition, there was a statistically significant difference between the two groups in the proportion and the mean score of subjects with pre-symptom of locomotive syndrome and locomotive syndrome. In the correlation analysis, grip strength was statistically significantly correlated with height, weight, skeletal muscle mass, waist circumference, timed up and go test, pre-symptom of locomotive syndrome and locomotive syndrome. Gait speed was significantly correlated with the timed up and go test and locomotive syndrome. Appendicular skeletal muscle index was significantly correlated with height, weight, waist circumference, hip circumference, and the pre-symptom of locomotive syndrome. Conclusion : In conclusion, sarcopenia is closely related to height, weight, skeletal muscle mass and functional mobility, as well as the pre-symptom of locomotive syndrome and, locomotive syndrome. In consideration of this, the prevention and management of sarcopenia should be made accordingly.

• Korean Journal of Applied Biomechanics
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• v.19 no.4
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• pp.771-778
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• 2009

We aimed to determine the effect of heel height on foot pressure by comparing and analyzing data on foot pressure in shoes with different heel heights. Qn the basis of a previous study, we selected 3cm and 7cm as the shoe heel heights preferred by female college students. We divided 10 female students into forefoot and hindfoot to measure vertical force, maximum pressure, and average pressure. The average pressure on the forefoot was higher and that on the hindfoot was lower in the case of 7cm high-heeled shoes. The maximum pressure on the forefoot was significantly higher in the case of the 7cm heel height (p<.05). The vertical force, maximum pressure, and average pressure on the hindfoot were also significantly higher in the case of the 7cm heel height (p<.05). The results showed that wearing 7cm high-heeled shoes exerted greater maximum pressure on the forefoot and greater vertical force, maximum pressure, and average pressure on the Hndfoot. This leads to increase in confining pressure caused by high pressure distribution over the forefoot and increase in the pressure on the hindfoot, which may cause deformation of toes and heel pain over a long period. Therefore, female college students who wish to wear high heels are recommended to wear 3cm high-heeled shoes rather than 7cm high-heeled shoes.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.11 no.1
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• pp.11-28
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• 2005

Spasticity has been defined as "a motor disorder characterized by a velocity-dependent increased in tonic stretch reflexes with exaggerated tendon jerks, resulting from hyperexcitability of the stretch reflex, as one components of the upper motorneuron syndrome". Spasticity is one of the common symptoms of stroke patients and frequently interferes with the motor functions such as gait, posture and activities of daily living. Therefore, its management is becoming a major issue in physical therapy. The purpose of this study was to determined the effects of reciprocal inhibition by isometric contraction of pre-tibia muscle on spasticity in hemiplegic patients through Hoffmann reflex. The subjects were consisted 45 patients who had hemiplegia due to stroke. All subjects randomly assigned to 3 group: manual reciprocal inhibition program group(manual group), neuromuscular electrical stimulation group(NMES group) and control group. The manual group received voluntary isometric contraction of pre-tibia muscle. The NMES group received neuromuscular electrical stimulation on tibialis anterior. The control group was not received any therapeutic intervention. Before and after experiments, Hoffmann reflex, M-wave and Modified Ashworth scale was measure in all patients. The data of 30 patients who complete experimental course were statistically analysed. Modified Ashworth scale were significantly decreased after experiment in manual group(p<.01). The Hmax/Mmax ratios were significantly decreased after experiment in manual group(p<.o1). There were no statistical difference between pre-test and post-test with modified Ashworth scale in NMES group(p>.01). There were no statistical difference between pre-test and post-test with Hmax/Mmax ratios in NMES group(p>.01). There were no statistical difference between pre-test and post-test with modified Ashworth scale in control group(p>.01). There were no statistical difference between pre-test and post-test with Hmax/Mmax ratios in control group(p>.01). The present results revealed that reciprocal inhibition which produced by voluntary isometric contraction of pre-tibia muscle can be reduce spasticity of gastrocnemius. Therefore, reciprocal inhibition is useful to improve functional activities in hemiplegic patient. Further study should be done to analyse the effects of intervention duration of reciprocal inhibition, appropriate muscle contraction, optimal time to apply the reciprocal inhibition in more long period.

• Journal of Life Science
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• v.21 no.9
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• pp.1336-1345
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• 2011

The purpose of this study was to analyze and compare the effects of exercise science of shoes for Aged' health promotion. Kinematic and kinetic data were collected using cinematography and the Zebris system (Zebris Emed Sensor Platform, GR-DVL9800) to analyze pressure of foot and ground reaction force. Subjects recruited were 20 healthy elderly men. They walked at 1.36m/sec velocity wearing type A (domestic), type B (foreign) and walking shoes (A company). One-way ANOVA was used to analyze statistics. The results were as following: no significant differences were observed in gait variables among the three groups (p<0.05). There was a significant difference in max pronation angle of heels examined among the three groups (p<0.05). There were no significant differences in kinetic variables (ground reaction force and max pressure) among the three groups (p<0.05). A physiology study was performed to analyze the effects of walking with shoes with silver added to them on percent body fat, resting metabolic rate and energy expenditure. Sixty adults males were recruited from the public health center. They were divided into four groups. C: control group (n=20), EY: elderly Y group (n=20), and EO: elderly O group (n=20). The results of this study were as follows: percent body fat was decreased following each exercise period, however, not all the groups showed a significant difference. The change of resting metabolic rate was significantly increased in HI (high intensity) and LI (low intensity) periods in the C and EY groups. However, there was no significant difference in the EO group. The mean energy expenditure during and after exercise were significantly lowered in all periods compared to the control group.

• Korean Journal of Applied Biomechanics
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• v.26 no.4
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• pp.397-405
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• 2016

Objective: Pilates is a low/mid-intensity exercise that can be easily performed by elderly individuals as it is an individual body-oriented exercise. It is also a cardio workout that can be performed anywhere to develop strength and flexibility. Therefore, we investigated the effects of 8 week Pilates program on the balancing ability of elderly individuals. Method: The research participants were selected from elderly residents in B city. Ten individuals voluntarily signed an agreement to undergo free measurements as well as to participate in the workout program. (Height: $157.1{\pm}11.9cm$, Weight: $61.7{\pm}8.0kg$). The Pilates exercise was performed 60 minutes a day, three times a week for a total of eight weeks. The measurement variables used to test balance were the vestibular test, 5 m habitual and maximum walk test and 3 m tandem walk test. A series of paired t-test were conducted using IBM SPSS Statistics 23.0 to analyze all the research data collected in order to determine the balance ability of the participants before and after the Pilates program. Additionally, the statistically significant level for all analysis was set to ${\alpha}=.05$. Results: In the vestibular test, some meaningful changes were observed in the length envelope area (ENV) while standing on one foot, but there were no significant differences in the ENV, rectangle(REC), root mean square, and total length. Results also revealed that statistically significant differences existed in the 5 m habitual and maximum walk test, as well as the 3 m tandem walk test. Conclusion: To summarize the findings, the 8 week Pilates program employed in this study significantly improved the dynamic balance of the elderly participants. Thus, elderly individuals that frequent perform Pilates are expected to enjoy positive benefits such as increased balance and fewer falling accidents.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.2105-2110
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• 2008

Embedding the compact wearable units to monitor the health status of a person has been analysed as a convenient solution for the home health care. This paper presents a method to detect fall from the other activities of daily living and also to classify those activities. This kind of ambulatory monitoring of the elderly and people with limited mobility can not only provide their general health status but also alarms whenever an emergency such as fall or gait has been occurred and a help is needed. A timely assistance in such a situation can reduce the loss of life. This work shows a detailed analysis of the data received from a chest worn sensor unit embedding a 3-axis accelerometer and depicts which features are important for the classification of human activities. How to arrange and reduce the features to a new feature set so that it can be classified using a simple classifier and also improving the classification resolution. Principal component analysis (PCA) has been used for modifying the feature set and afterwards for reducing the size of the same. Finally a Neural network classifier has been used to analyse the classification accuracies. The accuracy for detection of fall events was found to be 86%. The overall accuracy for the classification of Activities or daily living (ADL) and fall was around 94%.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.383-392
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• 2020

This study was to compare the effects of joint mobilization, treadmill with insole, and joint mobilization and treadmill with insole on pain, pelvic angle, and foot pressure in patients with sacroiliac joint pain. 24 patients randomly assigned to joint mobilization group(n=8), treadmill with insole group(n=8), or joint mobilization and treadmill with insole group(n=8). Each groups were conducted 30 minutes a day, two days a week for four weeks. Pain was evaluated using visual analogue scale and pelvic angle was measured using palpation meter and foot pressure(fore/rear ratio) was measured using Gateview AFA-50 before intervention and after 4 weeks. All groups were significant differences pain in intragroup(p<.01). In pelvic angle, the joint mobilization group was statistically significant in the anterior tilt only, the joint mobilization and treadmill with insole group showed statistically significant improvement in both anterior and posterior tilt(p<.01), and the treadmill with insole group did not show any statistically significant change(p>.05). Also the joint mobilization and treadmill with insole group were significant differences in foot pressure(p<.01). All the interventions reduce sacroiliac joint pain and joint mobilization and treadmill with insole training are most effective changes in pelvic angle and foot pressure. This study can be used as a basic data for prevention of injury, posture correction and gait training in patients with sacroiliac joint pain, as well as chronic low back pain and plantar pressure problem.