• School Mathematics
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• v.6 no.3
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• pp.283-299
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• 2004

It is a very important objective of mathematical education to lead students to apply mathematics to the problem situations and to solve the problems. Assuming that mathematical modeling is appropriate for such mathematical education objectives, we must emphasize mathematical modeling learning. In this research, we focused what mathematical concepts are learned and what reasoning are applied and used through mathematical modeling. In the process of mathematical modeling, the students used several types of reasoning; deduction, induction and abduction. Although we cannot generalize a fact by a single case study, deduction has been used to confirm whether their model is correct to the real situation and to find solutions by leading mathematical conclusion and induction to experimentally verify whether their model is correct. And abduction has been used to abstract a mathematical model from a real model, to provide interpretation to existing a practical ground for mathematical results, and elicit new mathematical model by modifying a present model.

• PNF and Movement
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• v.18 no.2
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• pp.255-263
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• 2020

Purpose: The purpose of this study was to investigate the effect of proprioceptive neuromuscular facilitation (PNF) lower extremity pattern on the dominant leg on muscle activity of the lower extremity supported by the ground. Methods: The subjects were 20 healthy males living in Busan. All subjects performed four direction PNF lower extremity patterns, and data were collected by surface electromyography from the gluteus medius (GM), tensor fascia latae (TFL), vastus medialis oblique (VMO), vastus lateralis oblique (VLO), and semitendinosus (STD) muscles of the opposite lower extremity during PNF lower extremity pattern. The PNF lower extremity pattern applied to the dominant leg was (1) flexion/adduction/external rotation with knee flexion; (2) extension/abduction/internal rotation with knee extension; (3) flexion/abduction/internal rotation with knee flexion; and (4) extension/adduction/external rotation with knee extension pattern, repeated 3 times per pattern and using the average value of the collected results. Collected muscle activity values were analyzed by one-way ANOVA, and post-hoc Tukey testing was performed to check between-group differences. The statistical significance level was set at α = 0.05. Results: GM and TFL flexion/abduction/internal rotation pattern with knee flexion was significantly higher than other patterns. VMO and VLO extension/adduction/external rotation pattern with knee extension was significantly higher than other patterns. STD flexion/adduction/external rotation pattern with knee flexion was significantly higher than other patterns. Conclusion: The study confirms differences in lower extremity muscle activity for the PNF lower extremity pattern, indicating that selective muscle contraction induction is possible using a pattern appropriate to the purpose of treatment.

• The Journal of Korean Physical Therapy
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• v.12 no.2
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• pp.95-105
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• 2000

Glenohumeral internal and external rotation with shoulder abducted in the frontal plane often causes impingement of the supraspinatus tendon. whereas similar activity in scapular plane does not cause impingement. The Purpose of this study was to determine if assessment among the three positions as 30 degrees, 60 degrees, 90 degrees abduction in the sitting position of the scapular plane could be affected the comparison between intemal and external peak torque, total work, average power. In this study, Isokinetic shoulder rotational strength was evaluated in twenty healthy male university students, using the Cybex NORMTM System (CYBEX Division of LUMEX, Inc., Ronkonkoma, New York). Test data was gathered in the plane of the scapular, 30 degrees of horizontal flexion anterior to coronal plane, and the subjects performed the test with the arm 30, 60, and 90degrees abducted in the sitting position. also, test speed was set at deg/sec. Statistical analysis was performed using SPSS 7.5 for Windows software and mean and standard deviations were calculated. ANOVA was used to analyze the difference of the values in the three test positions. A paired t-test was used of examining the difference in the means peak torque between external and internal rotation. Not any significant difference was found among three abduction positions in scapular plane, even though there was a consistent pattern of greater strength in the abducted position of 60 degrees. Internal relation strength peak torque and total work were greater than those of external rotation in every test positions.

• The Research Journal of the Costume Culture
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• v.25 no.3
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• pp.301-314
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• 2017

This study focused on the movement adaptability of $19^{th}$ century classical opera stage costumes. Researchers focused on a basic $19^{th}$ century women's jacket. The study analyzed movement adaptability using ROM (range-of-motion) tests of the upper limb flexion and abduction postures. It developed two research garments to mimic basic $19^{th}$ century style jackets with or without gussets at the axilla. The ROM experiment identified the gusset size as 11cm in length. Experimental postures included upper limb flexion and abduction. The study measured subjective comfort at 8 postures. These postures included the flexion and abduction of the arms and torso. Subjects also evaluated the subjective comfort of the rotation posture of the torso. Researchers evaluated the similarities between research garments' silhouettes and the $19^{th}$ century women's jacket. The study used a 3D virtual fitting system to evaluate fit, and specialists further analyzed fit with photographs and 3D virtual graphics. The results are as follows. The silhouettes of both research garments were similar to the silhouettes of the $19^{th}$ century western women's jacket. The jacket with axilla gusset had a better fit than the basic style jacket. The basic style jacket without the axilla gusset showed limited movement adaptability at the shoulder joint and it caused discomfort at the axilla and elbow. The 3D virtual fit test was not a suitable method for analyzing silhouette similarity.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.373-380
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• 2015

This study which was conducted on male tennis player on one hand(OH) & two hand(TH) backhand stroke and how both motion differed on low extremity movement with each feature analyzed in detail, the result as follow. The motion of TH based on resultant velocity, appeared to be a higher than OH, which was important variable in determining the ball speed. Contrary to TH where the player minimized the motion in the lower body and finalized a stroke through the turn of the trunk as if sticking the ball closed to the body, OH was carried out such that the player appeared to chase the ball. Whereas in OH, the knee joint extension moment was not found to be larger than TH, the opposite result came out for abduction moment and internal rotation moment. In the case of hip joint, consisted of extension, abduction and internal rotation moment, the outcome emerged to be greater for TH with conspicuous difference in abduction moment. Flection moment for TH overwhelmed in TH though both adduction and external rotation moment brought about similar outcome for both strokes.

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.145-151
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• 2006

A large interindividual variability and some abnormally kinematic patterns at the lower extremity were the main features of the gait in children with Down syndrome. The purposes of this study were to investigate the gait asymmetry and biomechanical difference between dominant leg and non dominant leg in children with Down syndrome. Seven boys with Down Syndrome(age: $120{\pm}0.9yrs$, weight $34.4{\pm}8.4kg$, leg length: $68.7{\pm}5.0cm$) participated in this study. A 10.0 m ${\times}$ 1.3 m walkway with a firm dark surface was built and used for data collection. Three-dimensional motion analyses were performed to obtain the joint angles and range of motions. The vertical ground reaction forces(%BW) and impulses($%BW{\cdot}s$) were measured by two force plates embedded in the walkway. Asymmetry indices between the legs were computed for all variables. After decision the dominant leg and the non dominant leg with max hip abduction angle, paired samples t-test was employed for selected kinematic and ground reaction force variables to analyze the differences between the dominant leg and the non dominant leg. The max hip abduction angle during the swing phase showed most asymmetry, while the knee flexion angle at initial contact showed most symmetry in walking and running. The dominant leg showed more excessive abduction of hip in the swing phase and more flat-footed contact than the non dominant leg. Vertical peak force in running showed more larger than those of in walking, however, vertical impulse showed more small than walking due to decrease of support time. In conclusion, the foot of dominant leg contact more carefully than those of non dominant leg. And also, there are no significant difference between the dominant leg and the non dominant leg in kinematic variables and ground reaction force due to large interindividual variability.

• Korean Journal of Human Ecology
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• v.24 no.5
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• pp.687-700
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• 2015

Lines of non-extension (LoNEs) on torso surface during arm abduction were investigated to provide appropriate location for inserting less-extensible yarns which can be used as seams for design and or clothing pressure variation. As experimental methods, reference points about 3 cm apart were marked on the skin and scanned at 30, $90^{\circ}$ and $135^{\circ}$ arm abduction. Skin deformation was measured by connecting reference points in horizontal, vertical and various angles of diagonal directions. Observation of skin deformation was made within the separated sections of the torso as well as integrated ones to cover the various occasions of design application. LoNEs of front and back torso were provided as mapping lines. Actual compression wear of three types was constructed with different pattern reduction rate at each separated section using LoNEs as boundary cutting lines. Clothing pressure and subjective evaluations of those three compression wear were evaluated by six subjects. LoNEs found in this study were useful as seam lines to differentiate clothing pressure at each part of the body, providing positive wear sensation. It is also expected that LoNEs can be paths for less strechable conductive yarns of IT-integrated upper garments.

• Physical Therapy Korea
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• v.23 no.3
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• pp.57-67
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• 2016

Background: Many previous studies recommended the side-lying hip abduction (SHA) exercise for targeting the gluteus medius (Gmed) and gluteus maximus (Gmax) muscle activity while the decreasing tensor fasciae latae (TFL) activation. Mischoice of hip position and angle in SHA may increase the risk of lower extremity injuries and undesirable muscle activation. However, information is limited on the effect of composite hip flexion angles and hip rotation on the gluteal muscle activity during SHA. Objects: This study aimed to compare muscle activity (Gmed, TFL, and Gmax) and activity ratios (Gmed/TFL, Gmax/TFL, and Gmed/Gmax) using surface electromyography (EMG) during SHA exercise at three different hip flexion angles either with or without internal rotation (IR) in subjects with Gmed weakness. We hypothesized that applying hip flexion and IR during SHA would increase gluteal muscle activity and decrease TFL activity. Methods: Muscle activity and activity ratios in 20 volunteers with Gmed weakness during 6 different SHA were investigated with surface EMG. One-way repeated-measures analysis of variance was used to determine the statistical significance. Results: Significant differences were found among the six different exercises for Gmed ($F_{2,41}=11.817$, p<.001) and Gmax ($F_{3,52}=5.513$, p=.003) muscle activity, and Gmed/TFL ($F_{3,54}=8.735$, p<.001) and Gmax/TFL ($F_{2,37}=4.019$, p=.028) activity ratios. Conclusion: Applying hip flexion is an effective method for increasing gluteal activity, and it elicits great Gmed/TFL and Gmax/TFL activity ratios during SHA in subjects with Gmed weakness.

• Physical Therapy Rehabilitation Science
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• v.6 no.1
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• pp.14-19
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• 2017

Objective: To investigate the effect of performing three different bridge exercise conditions on the activities of four different muscles using surface electromyography (sEMG) in healthy young adults. Design: Cross-sectional study. Methods: A total of 20 healthy young adults (10 males, 10 females) voluntarily participated in this study. All subjects randomly performed three different bridge conditions as follows: general bridge exercise, isometric hip abduction (IHAB) with a blue Theraband (Hygenic Corp., USA), and isometric hip adduction (IHAD) with a Swiss ball (Hygenic Corp.). The muscle activities of bilateral erector spinae (ES), gluteus maximus (GM), biceps femoris (BF), and external oblique (EO) muscles during the bridge exercises were measured using sEMG. Subjects performed each of the three bridge conditions three times in random order and mean values were obtained. Results: For bilateral ES and BF, there was a significant increase in muscle activity in the IHAD condition compared to the general bridge and IHAB condition (p<0.05). For bilateral GM, there was a significant increase in muscle activity in the IHAB condition compared to the general bridge condition (p<0.05) and there was a significant increase in muscle activity in the IHAB condition compared to IHAD condition (p<0.05). For left EO, a significant increase was observed in the IHAD condition compared to the general bridge condition (p<0.05). Conclusions: ES and BF muscle activity increases were observed with hip adduction and increased GM activity was observed with hip abduction. These findings may be applicable within the clinical field for selective trunk and lower extremity muscle activation and advanced rehabilitation purposes.

• Physical Therapy Korea
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• v.26 no.1
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• pp.75-83
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• 2019

Background: A tight iliotibial band (ITB) may lead to lateral patellar maltracking, compression, and tilt, and dominant vatus lateralis (VL) muscle activation relative to vastus medialis oblique (VMO) can laterally displace the patella, which leads to anterior knee pain. Therefore, an effective management technique is needed to stabilize the patella in individuals with tight ITB. Increased stability during the modified Thomas test has the potential to decrease compensatory motion and thus to selectively stretch the ITB. Objects: The purpose of this study was to determine the effects of ITB stretching in the modified Thomas test position on ITB flexibility, patellar translation, and muscle activities of the VMO and VL during quadreceps-setting (QS) exercise in individuals with tight ITB. Methods: Twenty-one subjects with tight ITB were recruited. Digital inclinometer was used to measure the hip adduction angle during the modified Ober test. Universal goniometer was used to measure the hip abduction angle during the modified Thomas test. Ultrasonography was used to measure the patella-condylar distance. Electromyography was performed to collect data of muscle activities. Paired t-test was used to determine the statistical significance between pretest and posttest. Results: The range of hip adduction in modified Ober test increased (p=.04) and the range of hip abduction in the modified Thomas test decreased after ITB stretching (p<.01). There was no difference between lateral patellar translation (p=.18). VMO muscle activity significantly increased after ITB stretching during QS (p<.01). VL muscle activity had no difference after stretching. Conclusion: The ITB stretching in the modified Thomas test position can be suggested as a management method for improving ITB flexibility and VMO muscle activity in individuals with tight ITB.