• Journal of the Korea Fashion and Costume Design Association
• /
• v.16 no.2
• /
• pp.31-40
• /
• 2014

The purpose of the study was to examine model postures at fashion shows with respect to expressing fashion images including elegance and neutral-gender images. Data were gathered from the fashion shows held 2000 S/S through 2009 F/W, when elegance and neutral-gender fashion images were obvious in fashion collections. Three designer brands representing elegance and neutral-gender fashion images were selected by the researcher and fashion specialists including graduate students majoring in fashion. The fashion collection photos representing each image were selected from style.com, a website which contains four world's biggest fashion collections. The results showed different hand positions as a model posture according to fashion images. In the neutral-gender image, 16 photos (47%) showed a hand position at pockets, in the elegance image, 24 photos (82.3%) showed a hand position laying down by the sides. Also, walking pose was shown to be different between two fashion images. In the neutral-gender fashion image, 16 photos (52.9%) revealed a pose of 'natural walk', while 29 photos (100%) showed a pose of 'walk in a straight line' in the elegance imaged fashion. In conclusion, the neutral-gender image photos showed the pocket-positioned hand and the 'natural walk' poses more than elegance image photos, and elegance image photos revealed the hand position laying down by the sides and the 'walk in a straight line' poses than the photos of the neutral-gender image.

• Steel and Composite Structures
• /
• v.28 no.5
• /
• pp.589-606
• /
• 2018

The previous studies reflected the significant effect of neutral-axis position and coupling of in-plane and out-of-plane displacements on behavior of functionally graded (FG) nanobeams. In thin FG beam, this coupling can be eliminated by a proper choice of the reference axis. In shear deformable FG nanobeam, not only this coupling can't be eliminated but also the position of neutral-axis is dependent on through-thickness distribution of shear strain. For the first time, in this paper it is avoided to guess a shear strain shape function and the exact shape function and consequently the exact position of neutral axis for arbitrary gradation of higher order nanobeam are obtained. This paper presents new methodology based on differential transform and collocation methods to solve coupled partial differential equations of motion without any simplifications. Using exact position of neutral axis and higher order beam kinematics as well as satisfying equilibrium equations and traction-free conditions without shear correction factor requirement yields to better results in comparison to the previously published results in literature. The classical rule of mixture and Mori-Tanaka homogenization scheme are considered. The Eringen's nonlocal continuum theory is applied to capture the small scale effects. For the first time, the dependency of exact position of neutral axis on length to thickness ratio is investigated. The effects of small scale, length to thickness ratio, Poisson's ratio, inhomogeneity of materials and various end conditions on vibration and buckling of local and nonlocal FG beams are investigated. Moreover, the effect of axial load on natural frequencies of the first modes is examined. After degeneration of the governing equations, the exact new formulas for homogeneous nanobeams are computed.

• The Korean Journal of Pain
• /
• v.24 no.3
• /
• pp.141-145
• /
• 2011

Background: Stellate ganglion block is usually performed at the transverse process of C6, because the vertebral artery is located anterior to the transverse process of C7. The purpose of this study is to estimate the location of the transverse process of C6 using the cricoid cartilage in the performance of stellate ganglion block. Methods: We reviewed cervical lateral neutral-flexion-extension views of 48 patients who visited our pain clinic between January and June of 2010. We drew a horizontal line at the surface of the cricoid cartilage in the neutral and extension views of cervical lateral x-rays. We then measured the change in the shortest distance from this horizontal line to the lowest point of the transverse process of C6 between the neutral and extension views. Results: There was a statistically significant difference in the shortest distance from the horizontal line at the surface of the cricoid cartilage to the lowest point of transverse process of C6 between neutral position and neck extension position in both males and females, and between males and females in both neutral position and neck extension position. The cricoid cartilage level was 4.8 mm lower in males and 14.4 mm higher in females than the lowest point of transverse process of C6 in neck extension position. Conclusions: Practitioners should recognize that the cricoid cartilage has cephalad movement in neck extension. In this way, the cricoid cartilage can be still useful as a landmark for stellate ganglion block.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.9 no.5
• /
• pp.491-497
• /
• 2004

This paper presents a new rotor position estimation method for brushless DC motors. It is clear that the estimation error of the rotor position provokes the phase shift angle misaligned between the phase current and the back-EMF waveforms, which causes torque ripple in brushless DC motor drives. Such an estimation error can be reduced with the help of the proposed neutral voltage-based estimation method that is structured in the form of a closed loop observer. A neutral voltage appearing during the normal mode of the inverter operation is found to be an observable and controllable measure, which can be dealt with for estimating an exact rotor position. This neutral voltage is obtained from the DC-link current, the switching logic, and the motor speed values. The proposed algorithm, which can be implemented easily by using a single DC-link current and the motor terminal voltage sensors, is verified by simulation and experiment results.

• The Journal of Korean Physical Therapy
• /
• v.33 no.1
• /
• pp.40-46
• /
• 2021

Purpose: This study compared the muscle activity of the lower limb according to the three types of fixed angles of the ankle joint during a lunge exercise. Methods: Twenty healthy subjects performed the lunge motion in a trial including the three types of fixed angle. The lunge motion with a neutral, 20° dorsiflexion, and 20° plantarflexion of the ankle joint were randomized and measured repeatedly. The muscle activity of the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF), and semitendinosus (ST) was measured by surface electromyography. Results: In the change in ankle joint angle, the RF, VL, BF, and ST muscle activity showed significant differences (p<0.05). In the 20° dorsiflexion position, the muscle activity of VL, BF, and ST showed a significant decrease compared to that in the neutral position (p<0.017). The muscle activity of RF and VL in the neutral position was greater than that in the 20° plantarflexion position (p<0.017). Only the muscle activity of the BF in the 20° plantarflexion position was significantly greater than the 20° dorsiflexion position (p<0.017). Conclusion: These results revealed a difference in the muscle activity of lower extremities in the proximal region according to the angle of the ankle joint during the lunge.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.1
• /
• pp.207-219
• /
• 2005

The purpose of this study was to determine the effect of the foot rotation on the lower limb muscles. Fourteen subjects performed step-up/step-down at a cadence of 80 beats/min, exercises with the foot neutral, $35^{\circ}$ internally rotated, and $35^{\circ}$ externally rotated, respectively. For each variable, a one-way analysis of variance (ANOVA) was used to determine whether there were significant differences between genders and among the eight types of jump. When a significant difference was found in jump type, post hoc analyses were performed using the Tukey procedure. A confidence level of p < .05 was used to determine statistical significance. The results showed that significant changes in averaged IEMG values occurred with the internal rotation of the foot in the lateral gastrocnemius during the knee extension, and in the semitendinosus during the knee flexion. During the knee extension, however, the internal rotation of the foot produced a significantly lower Averaged IEMG values than the neutral foot position in the medial gastrocnemius. The results also found that the peak IEMG activity of the rectus femoris during the knee extension for the external rotation of the foot was Significantly higher than the corresponding values in the neutral position of the foot, while the intenal rotaion of the foot exhibited a significant difference with the neutral position of the foot in the semitendinosus during the knee flexion. In general, the foot rotation position did not influence the average IEMG and Peak IEMG values of most muscles. The practice of adopting foot rotation to selectively strengthen individual muscles of the lower limb was not supported by this study. The external rotation of the foot produced high muscle activities in the quadriceps during the knee extension. For the knee extension, therefore, maintaining a laterally rotated position should be need for stable and comfortable position.

• Journal of the Korean Society of Physical Medicine
• /
• v.12 no.4
• /
• pp.113-122
• /
• 2017

PURPOSE: The purpose of this study was to investigate the comparison of muscle activity and mechanical loading according to the angle of ankle joint during a sit-to-stand (STS) task. METHODS: Thirty-four young participants performed the STS in a randomized trial with the ankle joint at a neutral, 15 degrees dorsiflexion and 15 degrees plantarflexion angle in a fixed sitting posture with the knee in 105 degrees flexion. Muscle activity of the tibialis anterior (TA), rectus femoris (RF), biceps femoris (BF), and gastrocnemius medialis (GCM) was measured, and the parameters calculated in relation to mechanical loading were the STS-time, maximum peak, minimum peak, and total sum of mechanical loading. RESULTS: In the dorsiflexion position, the muscle activity of the TA and GCM showed a significant increase (p<.05), and the STS time, maximum peak and total sum of mechanical loading showed a significant difference compared to that in the neutral position (p<.05). In the plantarflexion position, the muscle activity of the RF and GCM showed a significant increase (p<.05), while that of the TA showed a significant decrease (p<.05) compared to that in the neutral position. And the minimum peak was significantly increased than the neutral position (p<.05), and the maximum peak and total sum of mechanical loading were showed significant difference compared with dorsiflexion position (p<.05). CONCLUSION: These results show that there is a difference in muscle activity and mechanical loading when performing the STS movement according to the change in the ankle joint angle.

• Physical Therapy Korea
• /
• v.25 no.4
• /
• pp.46-52
• /
• 2018

Background: The hamstring muscles in the lower extremity are highly important for knee joint stability and can be classified into medial and lateral hamstrings according to the anatomical position, which have some different functions. To measure the strength of the individual hamstring muscles, manual muscle testing is clinically performed by dividing rotation postures into internal and external postures. However, this has no sufficient scientific background. Objects: This study aimed to test the difference that the tibial rotation would cause in the muscle activity of the medial and lateral hamstrings. Methods: The muscle activities of the biceps femoris, semitendinosus, and semimembranosus were measured in a total of three different postures (neutral position and internal and external rotations) with 3 replications. During the maximal isometric contraction, resistance was constantly provided by the string attached to the strap, not by manual resistance of the examiner. Before and after electromyography measurements, the participants underwent hamstring flexibility measurement using the active knee extension test in the supine position on the treatment table. Results: The semitendinosus had a 12.56% reduction in muscle activity in external rotation as compared with that in neutral position. The biceps femoris and semimembranosus showed reduced muscle activities in both external and internal rotations as compared with those in neutral position. Only the women showed significant decreases in the comparison between pre and post-active knee extension. Conclusion: Only the semitendinosus muscle was consistent with the anatomical speculation. However, the reduction in the muscle activity of the semitendinosus as compared with that in neutral position was only 12.56%, the clinical value of which may be difficult to justify.

• Physical Therapy Korea
• /
• v.17 no.4
• /
• pp.8-15
• /
• 2010

This study was designed to investigate the effect of different hand positions on scapulothorcic muscle activities during push-up plus exercises. Fourteen healthy males performed push-up plus exercises under three conditions (neutral, $90^{\circ}$ internally rotated, and $90^{\circ}$ externally rotated hand positions), during which the activities of the serratus anterior, pectoralis major, and upper trapezius muscles were recorded using surface electromyography. The statistical significance at three different hand positions was tested by repeated one-way ANOVA. The mean activities of the serratus anterior increased and the mean activities of the pectoralis major decreased in the order of neutral hand position, internally rotated hand position, and externally rotated hand position. There was a significant difference during push-up plus between neutral and externally rotated hand positions as well as in the serratus anterior/pectoralis major activity ratio (p<.0.5). However, no significant differences were found in the activity of the upper trapezius muscle or the serratus anterior/upper trapezius activity ratio. We suggest that the push-up plus exercise performed in the externally rotated hand position could a beneficial strategy for selective strengthening of the serratus anterior muscle, while minimizing the activity of the pectoralis major muscle.

• Journal of muscle and joint health
• /
• v.17 no.2
• /
• pp.142-150
• /
• 2010

Purpose: The purpose of this study was to examine EMG activities and VMO/VL ratio of the vastus medialis oblique, vastus lateralis, and rectus femoris during squat exercise (knee angle: 15, 45, and 60 degrees; tibial rotation: internal rotation, neutral, and external rotation). Methods: Twelve subjects performed squat exercise at each knee angle and tibial rotation while electromyographic (EMG) activity was collected. Statistical analysis consisted of two-way repeated measures analysis of variance with post hoc analysis. Results: There were significant main effects of knee angles and foot positions and interaction effect on EMG activities of vastus medialis oblique and vastus lateralis. VMO/VL ratios were significantly different by tibial rotations and there was an interaction effect. A neutral position produced significantly more VMO/VL activity ratio than that from internally rotated position and externally rotated position at 60 degrees. Conclusion: Considering the interaction effects for EMG activity across quadriceps muscles tested, the 60 degrees knee angle with a neutral foot position may provide the most effective condition for patients with acute patellofemoral syndrome.