• PNF and Movement
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• v.10 no.3
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• pp.25-31
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• 2012

Purpose : This study was intended to compare muscle activity in relation to knee joint angles on closed kinetic chain. Methods : A total of 13 subjects consisting of 5 adult males and 8 adult females were made to make movements maintaining knee joint angles at $30^{\circ}$, $45^{\circ}$ and $90^{\circ}$ on closed kinetic chain and the muscle activity occurring in their vastus medialis, rectus femoris and vastus lateralis was measured. Statistical data were analyzed using oneway ANOVA. Results : On closed kinetic chain, the muscle activity of the vastus medialis, rectus femoris and vastus lateralis increased the most at $90^{\circ}$ among the knee joint angles with statistically significant differences(p<0.05). Conclusion : On closed kinetic chain, it could be seen that as the angle of the knee joint increased, the muscle activity increased.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.570-571
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• 2021

The research on waste power batteries in China in the past ten years reveals that the power battery recycling industry is enormous but marred with several challenges. A study of China's current power battery closed-loop supply chain revealed some issues in the power battery recycling industry, such as imperfect supply chain, small recycling scale, asymmetric information, and imperfect profit distribution mechanism. This paper uses the theory of corporate social responsibility and consumer choice to propose a closed-loop network of power batteries based on block chain technology and analyzes the existing closed-loop supply chain of power batteries. Consequently, this study provides a new idea for developing the power battery closed-loop supply chain by proposing the closed-loop network of power batteries based on blockchain technology

• Journal of International Academy of Physical Therapy Research
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• v.1 no.2
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• pp.126-135
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• 2010

The purpose of this study is to investigate the effects of closed and open kinetic chain exercise for increasing knee joint function on the knee position sense in the normal adults. Thirty normal adults(male 15, female 15; mean age: $22.13{\pm}2.58$ years) were participated in this study into two groups, each with 15 people. The group I was trained that closed kinetic chain exercise on the knee joint and the group II was trained that open kinetic chain exercise on the knee joint. Exercise programs performed for 4 weeks, 3 times a week were using Shuttle 2000-1 closed kinetic chain exercise and Knee Extensor open kinetic chain exercise(HUR, Filand). The results of this study were as follows: 1) There were statistically significant decreasing of measuring error degree in $0-20^{\circ}$ were found between before and after training in closed kinetic chain exercise(p<.05). 2) There were statistically significant decreasing of measuring error degree in $21-40^{\circ}$ were found between before and after training in closed kinetic chain exercise(p<.05). 3) There were statistically significant decreasing of measuring error degree in $41-60^{\circ}$ were found between before and after training in closed kinetic chain exercise(p<.05). 4) There were statistically significant decreasing of measuring error degree in $0-20^{\circ}$ were found between before and after training in open kinetic chain exercise(p<.05). 5) There were statistically significant decreasing of measuring error degree in $21-40^{\circ}$ were found between before and after training in open kinetic chain exercise(p<.05). 6) There were statistically significant decreasing of measuring error degree in $41-60^{\circ}$ were found between before and after training in open kinetic chain exercise(p<.05). In conclusion, these results suggest that closed and open kinetic chain exercise has increased in the knee joint proprioception between before and after training. Especially, closed kinetic chain exercise could be more useful intervention than open kinetic chain exercise for increasing proprioceptive sense.

• PNF and Movement
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• v.13 no.2
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• pp.95-102
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• 2015

Purpose: The purpose of this study was to analyze the effect of arm flexion patterns of proprioceptive neuromuscular facilitation on muscle activation in the contralateral lower extremity. Open kinematic chain and closed kinematic chain positions were used. Methods: This study used an electromyogram (MP150, Biopac Systems, USA) to measure muscle activation in 20 healthy male students. Comparative analysis was completed on muscle activation of the vastus lateralis, biceps femoris, tibialis anterior, and gastrocnemius of the contralateral lower extremity. Open kinematic chain and closed kinematic chain positions were used with a unilateral arm flexion-abduction-external rotation pattern. Paired t-tests using the SPSS 12.0 for Windows analyzed the data produced by the electromyogram. Results: There was a statistically significant difference in muscle activation in the biceps femoris, gastrocnemius, and tibialis anterior when the open kinematic chain and closed kinematic chain positions were compared (p < 0.05). Conclusion: The biceps femoris, gastrocnemius, and tibialis anterior muscles showed greater muscle activation in the closed kinematic chain position when compared to the open kinematic chain position.

• Physical Therapy Korea
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• v.24 no.4
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• pp.11-19
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• 2017

Background: Methods for exercising serratus anterior (SA) and upper trapezius (UT) muscles are important for the recovery of patients with various shoulder disorders, yet the efficacy of closed or open kinetic chain exercises have not yet been evaluated. Objects: The purpose of this study was to compare the activation of the SA and UT muscles during scapular protraction considering both closed and open kinetic chain exercises. Methods: Thirty subjects were randomly divided into experimental groups (closed kinetic chain exercise) and control groups (open kinetic chain exercise) in which scapular protraction was performed at $90^{\circ}$ or $125^{\circ}$ shoulder flexion. Electromyographic activity data were collected from the SA and UT muscles per position and exercise method. Results: Separate mixed 2-way analysis of variance showed significant differences in the activation of the SA (F1,28=6.447, p=.017) and the UT (F1,28=35.450, p=.001) muscles between the groups at $90^{\circ}$ and $125^{\circ}$ shoulder flexion. Also, the SA/UT ratio measures at $90^{\circ}$ and $125^{\circ}$ shoulder flexion significantly differed between the groups (F1,28=15.457, p=.001). That is, the closed chain exercise was more effective than open chain exercise for strengthening the SA muscle and controlling the UT muscle, $125^{\circ}$ of shoulder joint was more effective than $90^{\circ}$. Conclusion: The findings suggest that scapular protraction with shoulder $125^{\circ}$ flexion at the closed kinetic chain exercise may be more effective in increasing SA muscle activation and decreasing UT muscle activation as well as increasing the SA/UT ratio than open kinetic chain exercise.

• Industrial Engineering and Management Systems
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• v.7 no.1
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• pp.78-89
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• 2008

The need for holistic modeling efforts for returns that capture the extended closed loop supply chain (CLSC) system at strategic as well as operational level has been clearly recognized by the industry and academia. Strategic decision-makers need comprehensive models that can guide them in efficient decision-making to increase the profitability of the entire forward and return chain. Therefore, determination of a near optimal design configuration, which includes the environmental, economical and technological capability factors, is important in strategic decision-making effort that affect the profitability of the closed loop supply chain. In this paper, we adopted an improved system dynamics methodology to tackle strategic issues that affect various performance measures, like market, time/cost, environment etc., for closed loop supply chains. After studying real life implementation issues in CLSC design, we presented guidelines for the PBM (Participative Business Modeling) methodology and presented its extension for the strategic dynamic system modeling of return chains. Finally, we demonstrated the measurement of operational performance by extending SD (system dynamic) application to closed loop supply chain management.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.3
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• pp.369-378
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• 2013

PURPOSE: The purpose of present study was to ascertain how the activity of the serratus anterior muscle, the upper trapezius muscle and the pectoral major muscle was affected while the upper arm was being flexed at 70, 90 and 110 degrees respectively in a closed kinetic chain exercise (wall push up plus) and an open kinetic chain exercise (static hug). METHODS: Sixteen healthy young men subjects participated in the study. Surface electromyography (EMG) data were collected from the dominant-side muscles during a closed kinetic chain exercise and an open kinetic chain exercise. The activity of each muscle was measured quantitatively, and by the use of the two-way repeated ANOVA, the data were compared with each other according to exercises and shoulder flexion angles. RESULTS: Results indicated that the closed kinetic chain exercise did not interact with the open kinetic chain exercise (p>.05). In both the closed kinetic chain exercise and the open kinetic chain exercise, the activity of the serratus anterior muscle became different significantly according to angles (p<.05). Its activity increased in order of 70, 90 and 110 degrees (p<.05). In both exercises and all angles, muscle activity was significantly higher in the serratus anterior muscle than in the upper trapezius muscle and the pectoral major muscle (p<.05). CONCLUSION: The above results show that there is a need to selectively control the exercise stress of the serratus anterior muscle in the case of the patients with the shoulder impingement syndrome characterized by the winged scapula, insufficient scapular protraction and upward rotation.

• Journal of Society of Preventive Korean Medicine
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• v.12 no.3
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• pp.115-128
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• 2008

Purpose : This study was performed to distinguish the muscle activation of vastus medialis and biceps femoris through open and closed kinetic chain exercise. Methods : 31 healthy male and female students in Daegu Health College were participated in this study. All subjects were conducted three types open and closed kinetic chain exercises to examine muscle activity during the last four seconds using the sEMG system. Collected EMG data were normalized using the maximal voluntary isometric contraction(MVIC). Results : MVIC of each muscle was showed significantly increased(p<0.5). In the case of open chain exercise, the type 3 exercise most increased than type 2 and 3 exercise in vastus medialis than biceps femoris muscle. The closed chain exercise presented type 6 exercise most increased than type 4 and 5 exercise in biceps femoris than vastus medialis. Conclusion : This study finally proved that muscle activity which maintains stability of knee differ from depending on the types of exercises. Therefore, the combination of the two chain exercises is believed to greatly contribute to increments in muscle activity.

• PNF and Movement
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• v.11 no.2
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• pp.87-93
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• 2013

Purpose : The purpose of this study was to investigate the effects of closed chain breathing exercise on thorax circumference increase and ROM of shoulder rotation for cervical vertebral cord injury patient's. Methods : 12 cervical vertebral cord injury patients volunteer to participate in this study. closed chain breathing exercise group of 4 subjects performed exercise three time a week. The deep breathing exercise group and general exercise group of 4 subjects performed exercise three time a week. We analyaed the descriptive statistics and $3{\times}2$ repeated measures ANOVA by SPSS 12.0 for window. Results : In comparison of rotation of shoulder ROM between pre and post value, the increase of rotation ROM of shoulder was significant in the closed chain breathing exercise group(p<.05). Conclusion : The closed chain breathing exercise helped to increased rotation ROM of shoulder.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.8 no.2
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• pp.75-86
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• 2004

In this study, a recursive algorithm for generating the equations of motion of a chain of rigid rods is presented. The methods rests upon the idea of replacing the rigid body by a dynamically equivalent constrained system of particles. The concepts of linear and angular momentums are used to generate the rigid body equations of motion without either introducing any rotational coordinates or the corresponding transformation matrices. For open-chain, the equations of motion are generated recursively along the serial chains. For closed-chain, the system is transformed to open-chain by cutting suitable kinematic joints with the addition of cut-joints kinematic constraints. An example of a closed-chain of rigid rods is chosen to demonstrate the generality and simplicity of the proposed method.