• Journal of The Korean Society of Integrative Medicine
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• v.7 no.1
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• pp.1-8
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• 2019

Purpose : The purpose of this study was to examine the correlation between static and dynamic balance according to the virtual reality-based squat and conventional squat exercise. Methods : Twenty four participants were randomly assigned to the virtual reality-based squat (VRS) group (n=12) or conventional squat (CS) group (n=12). The static balance (C90 area, C90 angle, trace length, sway average velocity) and dynamic balance (forward, rearward, leftward, rightward) were measured using a force plate by BT4. The VRS group used the virtual reality system during 4 weeks, while the CS group underwent classical squat training. Independent t-test was used to test the homogeneity of the general characteristics of the subjects. The collected data was analyzed using the paired t-test for static and dynamic balance comparisons before and after exercise in both groups and Pearson's test for the correlation between static and dynamic balance according to the measured time. The significance level was set to 0.05. Results : There was no significant correlation between group and static and dynamic balance related variables (p>.05). There was a significant correlation between measurement time and static and dynamic balance related variables (p<.05). According to the measurement time, the static balance parameter C90 area in the VRS group after exercise was significantly decreased (p<.05). The values of forward, leftward and rightward in the VRS group were significantly increased after exercise (p<.05). Conclusion : It is suggested that 20 normal healthy adult men and women who have normal balance ability can improve their ability to control their posture by improving the balance ability when applying virtual reality-based squat exercise.

• Physical Therapy Rehabilitation Science
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• v.13 no.2
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• pp.205-212
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• 2024

Objective: The purpose of this study is to confirm the exercise effect when combining wearable exercise assist robot, Bot fit's resist mode (Samsung Electronics) and stair climbing. Design: Cross-section study Methods: Targeting 53 adults and seniors, foot pressure and muscle activity were measured when climbing 3-story stairs using foot pressure measurement equipment (W-insole Science System) and surface muscle activity measurement equipment (sEMG; FreeEMG, BTS Bioengineering, Italy) using Bot Fit's resist mode. All subjects were measured without wearing Bot Fit, and the data between the two conditions were compared and analyzed. Results: The front area(p<0.01) and middle area(p<0.05) foot pressures of adults significantly increased when wearing the Bot fit. Frontal area foot pressure significantly increased in elderly people with knee arthritis and obesity(p<0.05). The gastrocnemius activity in all subjects significantly decreased after wearing Bot Fit(p<0.01). In elderly people with knee arthritis, the muscle activity of the rectus femoris was significantly reduced(p<0.05)., and in obese elderly people, the muscle activity of the gastrocnemius muscle was significantly reduced(p<0.05). Conclusions: Based on the results of this study, it is possible to induce correct stair climbing posture when climbing stairs using Bot fit resistance mode. In particular, it is expected to be an effective exercise for strengthening muscle endurance by increasing the activity of the rectus femoris muscle.

• Journal of the Korea Society of Computer and Information
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• v.25 no.3
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• pp.145-154
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• 2020

This paper proposes a corresponding bicycle fitting method through a number of clinical results and experiments, with the aim of standardizing the comprehensive bicycle fitting method with the aim of developing a system that incorporates bicycle fitting software and hardware to proceed more precisely and quickly. This bicycle fitting method can determine the value of bicycle setting for the rider through in-depth counseling, bicycle check, sophisticated body sizing and analysis, and from the bicycle adjusted to this setting, the posture and pedaling torque can be analyzed through fixed lading, which can be followed to find the most efficient setting value and optimize the bicycle to meet the needs of the rider. Such a fitting method can increase the satisfaction of bicycle riders and also be expected to prevent injury through accurate bicycle setting values. This paper can be established as a bicycle fitting technology that can be recognized even in the global market if the final bicycle fitting system is implemented as the result presented in the most concrete domestic and foreign countries.

• Physical Therapy Korea
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• v.23 no.1
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• pp.87-93
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• 2016

Background: Posture balance control is the ability to maintain the body's center of gravity in the minimal postural sway state on a supportive surface. This ability is obtained through a complicated process of sensing the movements of the human body through sensory organs and then integrating the information into the central nervous system and reacting to the musculoskeletal system and the support action of the musculoskeletal system. Motor function, including coordination, motor, and vision, vestibular sense, and sensory function, including proprioception, should act in an integrated way. However, more than half of stroke patients have motor, sensory, cognitive, and emotional disorders for a long time. Motor and sensory disorders cause the greatest difficulty in postural control among stroke patients. Objects: The purpose of this study is to determine the effect of visual and somatosensory information on postural sway in stroke patients and carrying out a kinematic analysis using a tri-axial accelerometer and a quantitative assessment. Methods: Thirty-four subjects posed four stance condition was accepted various sensory information for counterbalance. This experiment referred to the computerized dynamic posturography assessments and was redesigned four condition blocking visual and somatosensory information. To measure the postural sway of the subjects' trunk, a wireless tri-axial accelerometer was used by signal vector magnitude value. Ony-way measure analysis of variance was performed among four condition. Results: There were significant differences when somatosensory information input blocked (p<.05). Conclusion: The sensory significantly affecting the balance ability of stroke patients is somatosensory, and the amount of actual movement of the trunk could be objectively compared and analyzed through quantitative figures using a tri-axial accelerometer for balance ability.

• Journal of the Ergonomics Society of Korea
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• v.33 no.2
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• pp.143-153
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• 2014

Objective: The aim of this study is to investigate the effects of trunk-forearm supported sitting on trunk flexion angle, trunk extensor fatigue and seat contact pressure. Background: The relationship between sitting posture and musculoskeletal disorders of the trunk extensor fatigue and seat contact pressure has been documented. The trunk-forearm support type ergonomic chair was devised from the fact that trunk-forearm support has been reported to reduce trunk extensor activity and discomfort. Method: Using three different sitting postures, upright ($P_1$), trunk-forearm supported ($P_2$) and normal sitting ($P_3$), six healthy subjects participated in the study. Motion capture system was used to collect head and trunk flexion angle, and surface electromyography (sEMG) was used to collect myoelectric signal of upper trapezius, lower trapezius, erector spinae, multifidus, and pressure mat system was used to measure seat contact pressure. Results: When trunk and forearm were supported by the ergonomic chair, higher head flexion angle showed upright > trunk-forearm supported > normal in order, and muscle fatigue showed less than upright and normal sitting. Mean seat contact pressure decreased 19% than upright sitting. But muscle fatigue was not affected by each condition. Conclusion: Trunk-forearm supported sitting of the ergonomic chair showed positive effect in respect of trunk and head flexion angle, trunk extensor fatigue, seat contact pressure. To acquire comprehensive understanding of the effectiveness of the ergonomic chair, further studies such as anatomical effects from measurement of external applied loading effect to the body from interface pressure analysis are required. Application: The results of the publishing trend analysis might help physiological effects of trunk-forearm support type chair.

• Journal of Digital Contents Society
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• v.19 no.7
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• pp.1225-1235
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• 2018

In this study, as a part of practical and customized smart contents development planning research related to smart fitness contents associated with smart wear that can monitor physical activity, we investigated the potential needs for smart fitness contents through research. As a result, the potential needs for smart fitness contents is 'accessibility to use', 'inducement of interest', 'diverse story line' were derived at the stage of 'before exercise', 'Real - time voice coaching', 'accurate exercise posture monitoring', and 'personalized exercise prescription' were derived at the stage of 'during exercise'. At the stage of 'after exercise', 'substantial reward system', 'grading system', 'body figure change monitoring' and 'everyday life monitoring' were derived. At the stage of 'connection to the next exercise', 'triggering exercise motivation', 'high sustainability' wear derived.

• KIPS Transactions on Computer and Communication Systems
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• v.6 no.6
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• pp.271-280
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• 2017

In this paper, we propose a new safety system composed of wearable devices, driver's seat belt, and integrating controllers. The wearable device and driver's seat belt capture driver's biological information, while the integrating controller analyzes captured signal to alarm the driver or directly control the car appropriately according to the status of the driver. Previous studies regarding driver's safety from driver's seat, steering wheel, or facial camera to capture driver's physiological signal and facial information had difficulties in gathering accurate and continuous signals because the sensors required the upright posture of the driver. Utilizing wearable sensors, however, our proposed system can obtain continuous and highly accurate signals compared to the previous researches. Our advanced wearable apparatus features a sensor that measures the heart rate, skin conductivity, and skin temperature and applies filters to eliminate the noise generated by the automobile. Moreover, the acceleration sensor and the gyro sensor in our wearable device enable the reduction of the measurement errors. Based on the collected bio-signals, the criteria for identifying the driver's condition were presented. The accredited certification body has verified that the devices has the accuracy of the level of medical care. The laboratory test and the real automobile test demonstrate that our proposed system is good for the measurement of the driver's condition.

• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.373-378
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• 2012

The purpose of this study was to develop an electric riding machine for cycle fitting to control riding posture easily, to measure frame size quantitatively, and to overcome disadvantages of the traditional systems. The electric riding machine consisted of actuator, load controller, and display & control unit. The actuator unit by BLDC(BrushLess Direct Current) motor drives the saddle height up and down, the crank forward and backward, the handlebar up and down, and the handlebar forward and backward. The load controller unit controls loads by Eddy current controller with electromagnet and aluminum circular plate. The display & control unit consisted of frame size controller and display panel which shows top tube length(485~663mm), head tube length(85~243mm), seat tube length(481~671mm), and seat tube angle($62.7{\sim}76.4^{\circ}$). The range of frame size control for developed electric riding machine did not have difference compared to traditional commercial systems, but quantitative and precise control with 0.1 mm length and $0.1^{\circ}$ angle was possible through digital measurement. Unlike traditional commercial systems, frame size control was possible during riding through motor driven method, thus fitting duration decreased. It is necessary for further improvement to have feedback from users. It is believed that developed electric riding machine can help to develop domestic fitting system.

• Journal of Korean Physical Therapy Science
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• v.26 no.3
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• pp.70-75
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• 2019

Purpose: The purpose of this study was to investigate the changes of static and dynamic balance control ability according to the stability of shoes in elderly woman and female university student. Design: Cross-sectional study. Methods: Six elderly women and seven female university students were recruited for this study. The subject's static and dynamic balance were evaluated while wearing two different types of shoes (comfortable running shoe and masai walking shoe). The BT4 system was used to measure the static (postural sway area and velocity) and dynamic balance (limit of stability on forward, backward and left and right side). The measurement of static and dynamic balance control ability was performed in standing posture wearing comfortable running shoes and masai walking shoes. Results: In the static balance control ability, both female university students and elderly women showed significant increase in postural sway area and velocity when wearing unstable shoes (p<0.05) In addition, in the dynamic balance control ability, both female university students and elderly women showed significant decrease in limit of stability on forward and backward when wearing unstable shoes (p<0.05). Conclusion: In selecting shoes for the elderly, the stability of shoe should be considered for prevention of falls.

• Journal of the Korean Society of Physical Medicine
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• v.7 no.4
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• pp.459-469
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• 2012

PURPOSE: The purpose of the present study was to examine changes caused by asymmetric bag carrying methods to carry the bag with one shoulder only to plantar pressure during walking. METHODS: Twenty three normal adults without any gait problem participated in the present study. Experimental conditions used consisted of walking without carrying any bag(condition 1), walking wearing a bag on both shouders (condition 2), and walking wearing a bag on the right shoulder(condition 3) and the weight of the bag was set to 15% of each subject's body weight. All the subjects were instructed to participate in all experiments under these three conditions and plantar pressures were measured from the subjects' right and left feet using an F-scan system while the subjects were walking under the three conditions. To analyze the measured plantar pressure, the sole was divided into seven areas (Hallux, Toe, Met1, Met23, Met45, Mid foot and Heel) and maximum plantar pressures in individual areas were measured. RESULTS: The results of measurement of plantar pressures under three walking conditions did not show significant changes in any areas of the left and right feet except for the mid foot area of the right food. The asymmetry between the left and right feet was examined and the results showed significant differences only in area Met23 under condition 2 and did not show significant differences in any other areas. CONCLUSION: On comprehensively considering the results of the present study, it could be seen that asymmetric bag carrying did not have large effects on changes in plantar pressure during walking compared to symmetric carrying. The reason for this is considered to be posture adjusting mechanisms against load positions.