• PNF and Movement
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• v.20 no.2
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• pp.215-222
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• 2022

Purpose: The purpose of this study was to compare the effects of passive scapular upward rotation and posterior tilt and active scapular posterior tilt on the muscle activity of the upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA). Methods: Fifteen healthy subjects performed general arm elevation, arm elevation with passive scapular upward rotation and posterior tilt, and arm elevation with active scapular posterior tilt. For active scapular posterior tilt, the subjects were trained in this movement using visual biofeedback and a motion sensor. During each arm elevation condition, electromyography was used to measure the muscle activity of the UT, LT, and SA. The measured data were analyzed using a one-way repeated ANOVA. Results: LT muscle activity was significantly increased during arm elevation with active scapular posterior tilt compared to both general arm elevation and arm elevation with passive scapular upward rotation and posterior tilt (p < 0.05). SA muscle activity was greater during arm elevation with passive scapular upward rotation and posterior tilt than during general arm elevation (p < 0.05). There was no significant change in UT muscle activity among the tested arm elevation conditions (p > 0.05). Conclusion: Performing arm elevation with active scapular posterior tilt and performing arm elevation with passive scapular upward rotation and posterior tilt may be useful strategies for increasing muscle activation of the LT and SA, respectively.

• PNF and Movement
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• v.15 no.2
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• pp.177-183
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• 2017

Purpose: This study compared and analyzed the effect of the proprioceptive neuromuscular facilitation (PNF) arm extension pattern and leg flexion pattern on the contralateral lower extremity muscles when the patterns were applied to the same subject. Methods: In the study, 35 healthy men and women who understood the PNF patterns were selected as participants. The participants completed the PNF arm extension-abduction-internal rotation pattern and leg flexion-adduction-external rotation with knee flexion pattern in the supine position. While the patients' completed each pattern, the contralateral leg muscle activity was measured to examine the irradiation effect. The maximum isometric contraction time of the muscles to be measured was kept for 5 seconds, and the mean value was obtained by repeating the pattern three times. Results: When the leg flexion-adduction-external rotation with knee flexion pattern was completed, the muscle activity in the vastus lateralis, vastus medialis, biceps femoris, tibialis anterior, and gastrocnemius of the contralateral lower extremity was significantly greater than that found in the PNF arm extension-abduction-internal rotation pattern. Conclusion: The PNF leg flexion pattern showed greater muscle activity on the contralateral lower extremity than the arm extension pattern. Thus, the PNF leg extension pattern is more effective in the activation of the muscles associated with weight-bearing activity.

• PNF and Movement
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• v.12 no.3
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• pp.173-179
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• 2014

Purpose: The purpose of this study is to analyze the effect of arm leg flexion patterns of proprioceptive neuromuscular facilitation on the muscle activation of the contralateral lower extremity. Methods: In this study, Electromyogram MP150(Biopac system, USA) was applied to 20 healthy male subjects. Unilateral arm flexion- abduction- external rotation pattern and Unilateral leg flexion- adduction- external rotation with knee flexion pattern were applied within mid range of the supine position for measurement. The muscle activation of vastus lateralis, biceps femoris, tibialis anterior and gastrocnemius(medialis) muscle of the contralateral lower extremity were compared and analyzed during the applications. Results: The results of this study were summarized as follows: There was a statistically significant difference in the muscle activation of vastus lateralis and biceps femoris between the arm and leg patterns(P<0.05). There was a statistically significant difference in the muscle activation of gastrocnemius and tibialis anterior between the arm and leg patterns(P<0.05). Conclusion: contralateral vastus lateralis, biceps femoris, gastrocnemius and tibialis anterior muscles show the higher muscle activation in the leg pattern than one in the arm pattern.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.3
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• pp.161-166
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• 2003

In order to improve the fatigue lift of a lower control arm in the vehicle suspension, a new shape optimization procedure is presented. In this approach, the shape control point concept is introduced to reduce the numbers of shape design variables. Also, the two-level orthogonal way is employed to evaluate the design sensitivity of fatigue life with respect to those shape design variables, because the analytical design sensitivity information is not directly supplied from the commercial CAE softwares. In this approach, only the six design variables are used to approximate the shape of lower control arm. Then, performed are only 10 fatigue life analyses including the baseline design, 8 DOE models and the final design. The final design, the best combination obtained from the sensitivity information, can maximize the fatigue lift nearly two times as that of the baseline design, while reducing the 12 percentage of weight than it.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.5 s.248
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• pp.602-608
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• 2006

Vehicle components such as lower control arm are usually affected by heat during the welding process. As a result, residual stress is generated, which has much effect on mechanical performances such as crashworthiness and durability. In this study, the residual stress in lower control arm has been measured by the x-ray diffraction method and been analyzed by finite element methods. Heat transfer during seam weld process has been calculated and used in calculating thermal deformation with temperature dependent material properties. High residual stress has been found at vertical wall both by measurement and simulation. The simulation also showed the residual stress re-distribution when the component is subjected to cyclic loading condition.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.783-788
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• 2000

Hydroforming is a method for forming circular tubes. If this technology is to be applied economically, it is essential to have knowledge of the avoidance of failure cases as well as of the behavior of the tube in the tool under the compressive stress and forces that are exerted by the machine. A finite element simulation for manufacturing of lower arm from straight tubes, using the hydroforming method, was performed to investigate the effects of varying process parameters. Explicit method is used to simulate hydroforming in many cases, but that is not included flow rule. And then it needs simulation for implicit method. It was simulated by two methods, implicit and explicit, to compare the result of the hydroforming.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.4
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• pp.50-58
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• 1994

To examine the residual stress field resulting from stamping process for the lower control arm of a car, the explicit finite element analysis is performed for the stamping process by way of the ABAQUS Explicit. The residual stress is obtained in terms of the Von Mises stress and other parameters such as equivalent plastic strain, the change of blank thickness, the final configuration of the blank and the spring back effect are also considered. Moreover, discussed is the convergence of the explicit FEM versus the punch sped and the element discretization

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.94-101
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• 2003

Recently, miniaturization and weight reduction is getting more attention due to various benefits in automotive components design. It is a trend that the design of experiment(DOE) and statical design method are frequently used for optimization. In this research, the safety of lower control arm is evaluated according to its material change form S45C to A16061 for the reduction of arm's weight. The variance analysis on the basis of structure analysis and DOE is applied to the lower control m. We have proposed a statistical design model to evaluate the effect of structural modification by performing the practical multi-objective optimization considering mass, stress and deflection.

• Journal of International Academy of Physical Therapy Research
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• v.10 no.4
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• pp.1868-1872
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• 2019

Background: Lower trapezius muscle function is important for the prevention and treatment of shoulder injuries. However, scapular posterior tilt movement has been overlooked in lower trapezius strengthening exercise programs. Objective: To examine the effects of prone arm lifting with scapular posterior tilt (PALSPT) on trapezius muscles. Design: Crossover study Methods: 17 healthy males were recruited for participation in this study. Participants performed backward rocking diagonal arm lifting (BRDAL) and PALSPT. To train participants in scapular posterior tilt movements for PALSPT, visual biofeedback of scapular movements was provided using a motion sensor. Electromyography (EMG) activities of the middle and lower trapezius were recorded using a surface EMG system. Differences in middle and lower trapezius muscle activity between BRDAL and PALSPT exercises were analyzed. Results: Lower trapezius muscle activity was significantly greater during PALSPT than during BRDAL (p=.006). Although greater EMG activity was observed in the middle trapezius during PALSPT than during BRDAL, this difference was not significant (p=.055). Conclusions: The results of the present study indicate that scapular posterior tilt movements must be considered in lower trapezius muscle strengthening programs.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.7
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• pp.672-678
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• 2008

This paper proposes a new rehabilitation robot with upper and lower limb connections for gait training. As humans change a walking speed, their nervous systems adapt muscle activation patterns to modify arm swing for the appropriate frequency. By analyzing this property, we can find a relation between arm swinging and lower limb motions. Thus, the lower limb motion can be controlled by the arm swing for walking speed adaptation according to a patent's intension. This paper deals with the design aspects of the suggested gait rehabilitation robot, including a trajectory planning and a control strategy. The suggested robot is mainly composed of upper limb and lower limb devices, a body support system. The lower limb device consists of a slider device and two 2-dof footpads to allow walking training at uneven and various terrains. The upper limb device consists of an arm swing handle and switches to use as a user input device for walking. The body support system will partially support a patient's weight to allow the upper limb motions. Finally, we showed simulation results for the designed trajectory and controller using a dynamic simulation tool.