• Korean Journal of Applied Biomechanics
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• v.19 no.4
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• pp.637-645
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• 2009

The purpose of this study was to investigate the biomechanical alterations in the punching motion of 10 elderly women after 12 weeks of taekwonaerobics training. Seven infrared cameras(Qualisys MCU-240) and 2 force platforms(Kistler-9286AA) were used to acquire raw data. The results were as follows. First, the minimum joint angles of the lower limbs had a statistically significant difference between both the dorsiflexion/plantar flexion(1eft, $p=0.001^*$) and the inversion/eversion(both, $p=0.009^*$, $p=0.04^*$) from the ankle angle. There were differences in abduction/adduction(left, $p=0.04^*$) from the knee angle, as well as internal/external rotation(both, $p=0.07^*$, $p=0.02^*$) from the hip angle. Second, the maximum resultant joint moments of the lower limbs had statistically significant differences in the inversion/eversion moment from the ankle joint(both, $p=0.05^*$, $p=0.05^*$), the abduction/adduction moment(left, $p=0.08^*$) from the knee joint, and the internal/external rotation moment(right, $p=0.09^*$) from the hip joint. Third, the maximum resultant joint powers of the lower limbs had a statistically significant difference both in flexion/extension joint powers(both, $p=0.05^*$, $p=0.01^*$) and in abduction/adduction(both, $p=0.02^*$, $p=0.00^*$) from the hip joint, as well as abduction/adduction(left, $p=0.00^*$) from the knee joint, In conclusion, the elderly women were somewhat changed after 12 weeks of taekwonaerobics training.

• Korean Journal of Applied Biomechanics
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• v.13 no.1
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• pp.73-94
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• 2003

The purpose of this investigation was to analyze A kinematic analysis of the Kuzushi-arm motion when performing Morote-Seoinage in judo who was 5 females university representative judokas of light weight category in judo, and filmed on video cameras(60field/s). The data of this study digitizied by KWON3D 2.1 program computed the average and standard deviation calculated individual 5 trials with Programing Lab view 6i. From the data analysis & discussion, the following conclusions were drawn : 1) distance variable of attacking hand arm in kuzushi motion Left right(X direction) displacement variable was all of A, B, C pattern with moving left to right and leaning. Strip of displacement variable was ordo. to C(55.6cm), A(53.3cm), B(43.9cm) pattern, C pattern largely leaned to left Front Rear(Y direction) displacement variable was different A($131.3cm{\pm}3.1cm$), B($128.7{\pm}4.0cm$) and C(111.0cm) on ready position, 3 pattern leaned to rear direction. Strip of displacement was order to B(43.4cm), A(41.1cm) and C pattern(28.3cm). Up down(Z direction) displacement variable was all of A, B, C pattern leaned to up in the Kuzushi-phase and leaned to down in the Kake-phase. Strip of displacement was order to A(83.9cm), B(80.4cm), C pattern(71.9cm). 2) Shoulder joint angle variable Flexion and extension Ready position' angle was A($138.3{\pm}4.9^{\circ}$), B($142.9{\pm}3.7^{\circ}$) and C($164.5^{\circ}$) pattern, strip of flexion extension was order to C($80.9^{\circ}$), A($79.9^{\circ}$) and B($39.0^{\circ}$) pattern, greatly C pattern had largely angle change. Adduction and abduction : B and C pattern's angle change were adduction and abduction in the Kuzushi-phase after adduction in the Kake phase, A pattern's angle change was abduction in the Kuzushi-phase after adduction in the Kake phase. internal and external rotation : 3 pattern were internal rotation in the Tsukuri phase and external rotation in the Kake phase. After B and C pattern were external rotation and A pattern was internal rotation. 3) Elbow joint angle variable Flexion and extension 3 pattern's ready position angle were A($142.0{\pm}4.4^{\circ}$), B($123.5{\pm}5.5^{\circ}$) and C($105.5^{\circ}$) and flexion. Strip of flexion extension were order to A($57.9^{\circ}$), C($34.6^{\circ}$) and B($25.2^{\circ}$) pattern.

• Journal of the Ergonomics Society of Korea
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• v.24 no.2
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• pp.9-15
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• 2005

The purpose of this study is to quantitatively investigate perceived discomfort of complex shoulder postures with external loads and to propose a preliminary evaluation scheme of shoulder postures. Twelve healthy male adults participated in an experiment to rate their perceived discomfort of shoulder postures. The independent variables were shoulder flexion angle(45, 90 and 150$^{\circ}$), adduction/abduction angle(-30, -10, 0, 30 and 60$^{\circ}$), and external load(0, 1.5 and 3.0kg). The results revealed that the flexion angle, external load and their interaction significantly affected the perceived discomfort(p$<$0.05) but the effect of adduction/abduction angle on the discomfort was not significant(p$>$0.05). The effect of external load was much larger than that of any other factor with explaining about 81% of the total variation of discomfort scores. Based on the experimental results a preliminary scheme was presented to evaluate the stress of shoulder postures with external loads.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.8
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• pp.1181-1189
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• 2009

This research analyzes the relationship between the height of the sleeve cap and the mobility of arm movement. Ten Korean women participated as subjects. For test clothes, the AH/4+3, AH/4+1, and AH/4-1 height of the sleeve cap were varied. The sleeve circumference was adjusted according to the variation of the height of the sleeve cap. To analyze test clothing objectively, the range-of-motion of two selected movements (Arm Adduction/Abduction and Arm Flexion/Extension) was measured by Leighton flexometer and goniometer. Also, a wearer acceptability rating was examined for acceptance by the subject. Anova and Duncan's multiple range tests are used for statistical analysis. According to the results, the mobility of test clothing 2 and 3 improved 14.9% and 27.7% in Arm Adduction/Abduction, and 12.7% and 31.9% in Arm Flexion/Extension compared to the test clothing 1.

• The Journal of Korea Robotics Society
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• v.12 no.2
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• pp.206-216
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• 2017

This paper proposes a method to simultaneously estimate two degrees of freedom in wrist forces (extension - flexion, adduction - abduction) and one degree of freedom in grasping forces using Electromyography (EMG) signals of the forearms. To correlate the EMG signals with the forces, we applied a multi - layer perceptron(MLP), which is a machine learning method, and used the characteristics of the muscles constituting the forearm to generate learning data. Through the experiments, the similarity between the MLP target value and the estimated value was investigated by applying the coefficient of determination ($R^2$) and root mean square error (RMSE) to evaluate the performance of the proposed method. As a result, the $R^2$ values with respect to the wrist flexion-extension, adduction - abduction and grasping forces were 0.79, 0.73 and 0.78 and RMSE were 0.12, 0.17, 0.13 respectively.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.2
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• pp.76-83
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• 2004

This study aimed to empirically investigate perceived discomfort depending upon external load, upper limb postures and their holding time. Discomfort was obtained through an experiment, in which external load, wrist flexion/extension, elbow flexion, shoulder flexion and adduction/abduction were used as experimental variables. The subjects were instructed to hold given postures for 60s and to rate their subjective discomfort scores at 5s, 20s, 40s and 60s by using the free modulus method of magnitude estimation. The results showed that while only external load and elbow flexion were statistically significant at the holding time of 5s at ${\alpha}=0.05$ or 0.10, external load and upper limb postures excluding shoulder adduction/abduction significantly affected discomfort ratings at 20s, 40s and 60s at ${\alpha}=0.01$ or 0.05. Discomfort scores were also significantly different between four posture holding times at ${\alpha}=0.01$. The effects of external load and holding time were much larger than those of upper limb postures. Based on the results of this study, it is recommended that external load and holding time as well as working postures betaken into consideration to precisely quantify postural load in industry.

• Korean Journal of Applied Biomechanics
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• v.16 no.4
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• pp.73-81
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• 2006

The purpose of this study was to investigate the effects of strength training on knee joint torque during walking in an adolescent with trisomy-21 Down syndrome. One adolescent with Down syndrome and one normal child participated in this study. Strength training consisted of eight exercises: squat, hamstring curl, hip adduction, hip abduction, knee extension, toe raise, sit-ups, and hyperextension of the waist. The participant with Down syndrome was participated in strength training for 12 weeks, three times a week, three sets, 10-15 RM; resistance was adjusted according to the principle of progressive overload. To measure the effect of strength training, isokinetic strength variables and knee joint torques were measured before training and after 12 weeks of training. The participant with Down syndrome had some abnormalities in controlling knee motion during walking due to muscle hypotonia, ligament laxity, and weakness of muscles. Post-training isokinetic strength increased compared to pre-training measurements. Knee range of motion were increased after strength training. Strength training did not affect ad/adduction and in/exteranl moments but did have an effect on flexor/extensor moment and timing.

• Tuberculosis and Respiratory Diseases
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• v.52 no.3
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• pp.265-270
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• 2002

Vocal cord dysfunction (VCD) is respiratory disorder characterized by paradoxical closure of the vocal cord during the respiratory cycle leading to obstructive airway symptoms. The clinical presentation of VCD is often dramatic and its misdiagnosis as asthma or exercise-induced brochospasm(EIB) has led to inappropriate treatment including high dose corticosteroids, intubation, and tracheostomy. Many VCD patients are asymptomatic at rest and require exercise challenge to elicit symptoms and vocal cord abnormalities. The "gold standard" for the diagnosis of VCD remains laryngoscopy or bronchoscopy with direct visualization of paradoxical adduction of the vocal cords. We report a case of exercise-induced Vocal cord masqueraded as exercise-induced asthma unresponsive to corticosteroids. And bronchodilator confirmed by typical bronchoscopic findings with paradoxial adduction of the vocal cords.

• The Journal of Korean Physical Therapy
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• v.25 no.2
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• pp.117-125
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• 2013

Purpose: The purpose of this study was to investigate changes in movement strategies of lower limb joints depending on the type of heel during sit-to-stand. Methods: Twenty healthy females participated in this study. All subjects performed sit-to-stand three times each with three different types of heels - bare feet, 9 cm high-heeled shoes, and unstable shoes. Trails were conducted in random order. Three-dimensional motion analysis systems were used for collection and analysis of the kinematic data of lower limb movements. Results: Results of this study showed kinematic differences in pelvis, hip joints, knee joints, and ankle joints during sit-to-stand based on the type of heels. At the initial sit-to-stand, hip joint flexion, knee joint flexion, ankle joint flexion, and ankle joint inversion showed significant differences. The maximal angles of hip joint flexion, hip joint adduction, knee joint flexion, ankle joint flexion, and ankle joint inversion were significantly different, while hip joint adduction, pelvic forward tilt, hip joint rotation, knee joint flexion, ankle joint flexion, and ankle joint inversion differed significantly during the terminal of sit-to-stand. Conclusion: Therefore, the type of heel played an important role in selection of lower limb movements during sit-to-stand which were essential parts of daily life movements.

• PNF and Movement
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• v.14 no.3
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• pp.195-202
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• 2016

Purpose: This study investigates the influence of applying proprioceptive neuromuscular facilitation (PNF) leg patterns on the activation of three types of mesogluteal fibers at the opposite side. Methods: The target subjects of this study were 19 healthy men who voluntarily agreed to participate in the program. For all subjects, the following four PNF leg patterns were applied while they were in a standing position, and then, the activation of the gluteus medius at the opposite side was measured: (1) flexion abduction internal rotation pattern, (2) flexion adduction external rotation pattern, (3) extension abduction internal rotation pattern, and (4) extension adduction external rotation pattern. In each position, a pattern was executed three times in 5 s, and the average of each measurement was used for the statistics. Results: Among the PNF leg patterns, the activation of the mesogluteal fibers at the opposite side was most significant under the application of the extension abduction internal rotation pattern. The activation of the back muscular fiber was significantly high under the application of the flexion abduction internal rotation pattern. Conclusion: Selective application of PNF leg patterns can improve the functional activity of each mesogluteal fiber.