• Journal of Biomedical Engineering Research
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• v.28 no.6
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• pp.825-831
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• 2007

An elbow orthosis with a pneumatic rubber actuator has been developed to assist and enhance upper limb movements and has been examined for the effectiveness. The effectiveness of the elbow orthosis was examined by comparing muscular activities during alternate dumbbell curl exercises with and without the orthosis. The subjects participated in the experiment were younger adults in their twenties. The subjects were instructed to perform dumbbell curl motion in a sitting position with and without orthosis in turn and a dynamometer was used to measure elbow joint torque outputs in an isovelocity mode. The measurements were done with four various dumbbell loads: 0 kg, 1 kg, 3 kg, and 5 kg. The orthosis was pneumatically actuated and controlled in a passive mode. The most comfortable air pressure to the pneumatic actuator was determined to be 0.294MPa. Electromyography(EMG) was also measured during curl exercises. The muscles of interest were biceps brachii(BB), triceps brachii(TB), brachioradialis(Bo), and flexor carpi ulnaris(FCU) in the upper limbs. The experimental results showed that the muscular activities themselves significantly reduced with elbow orthosis on in performing similar activities without orthosis. As a result of this experiment, the effectiveness of the developed upper limb orthosis was confirmed and the level of assistance was quantified.

• The Journal of Korean Physical Therapy
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• v.28 no.1
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• pp.59-63
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• 2016

Purpose: The objective of this study was to identify determine the effect of the strap height on muscular activity of trunk and lower limbs muscles during bridging exercise with a sling. Methods: The subjects of the study were 17 healthy male adults. In order to For measurement of muscular activity, body surfaces electrodes were placed on areas including erector spinae, multifidus muscles, gluteus maximus, and hamstring and the results was were recorded based on three different heights of strap, which are Levels 1, 2, and 3. Results: The muscular activities in erector spinae, multifidus muscle, and gluteus maximus were significantly different in at all three heights (p<0.05)., Level 3 showed the highest the compared to Levels 1 and 2. In hamstring muscle, there was significant difference in levels 1 and 2, also and levels 1 and 3 (p<0.05),. Bbut there was no significant difference between 2 and 3. The ration of muscular activities in multifidus muscles/erector spinae and gluteus maximus/hamstrings were significantly different for all three strap heights (p<0.05). Also, Level 3 showed higher than 1 or 2. Conclusion: The results of this study suggests to adjustment of the level III, that which has high activity level of multifidus and gluteus maximus affecting trunk stability during bridging exercise using a sling.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.3
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• pp.133-139
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• 2018

PURPOSE: Despite the abundant literature available regarding the activity of intrinsic muscles, few studies have investigated the muscle activity of extrinsic muscles. Therefore, the present study compared the muscle activity of the peroneus longus, tibialis anterior, and abductor hallucis during short foot exercise in subjects with and without flat feet. METHODS: Twelve subjects with and without pes planus participated in this study. During the short foot exercises, muscular activity of the tibialis anterior, fibularis longus, and abductor hallucis longus were measured in both groups. To identify the effects of short foot exercises, navicular drop height was also investigated in pre and post short foot exercises. RESULTS: In a symptomatic group, the navicular drop height was significantly reduced at post measurement compared with pre-measurement. During the short foot exercise, the pes planus group showed significantly lower activities of the fibularis longus than the control group (p<.05). CONCLUSION: Similar to previous studies and clinical literature, short foot exercise was effective for alleviating navicular drop for a population with pes planus. In addition, subjects with pes planus showed decreased muscular activities of the fibularis longus, which suggests that considering extrinsic muscles such as fibularis longus is also important for rehabilitation of pes planus patients.

• PNF and Movement
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• v.10 no.1
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• pp.35-41
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• 2012

Purpose : This study was conducted to identify the effects of high heel shoes on surface electromyography(EMG) activities fo tibialis anterior(TA), soles(S), and gastrocnemius(G) in 12 healthy women. Methods : Subjects were composed of three group(sports shoes, 5cm heel height shoes, and 9cm heel height shoes). The muscle activity of the TA, G, S in the lower leg were measured using a surface EMG. Results : Results of one way repeated measures ANOVA of the after waling 30minutes standing task duration among the sport shoes, 5cm, and 9cm heel height conditions. The comparison of the muscular activities showed significant differences in the G muscles among the high heel shoes. Conclusion : Wearing high heel shoes for hours will bring inappropriate alignment of the lower limbs and cause postural changes or abnormal sensation and several other problems in the body, resulting in exposure to ankle sprain or fall injuries.

• Journal of the Ergonomics Society of Korea
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• v.30 no.2
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• pp.297-302
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• 2011

Many WMSDs(work-related-musculoskeletal disorders) have been reported in diverse industries and have also attracted much attention in recent years. Neck-related MSD is generally known as one of common WMSDs, especially it happens to workers who are working at the automobile assembly plants and/or shipyards. The awkward posture is considered as a main cause of neck-related MSDs. A neck supporter was developed to prevent neck-related MSDs, and 10 males were recruited to evaluate the newly developed neck supporter by measuring subjective discomfort ratings of whole body, shoulder, neck and neck-muscle activities. Muscle activities from four neck muscle groups(left/right sternocleidomastoid and upper/middle trapezius) were measured while simulating an automobile assembly task. Results showed that the neck supporter help to significantly improve subjective discomfort for whole-body, shoulder as well as neck body parts. The analyses of muscular activities also showed that the activities of left/right sternocleidomastoid muscles were statistically decreased with the neck supporter in this study. The muscle activities of upper/middle trapezius in case of wearing the neck supporter were not significantly different with the muscle activities in case of no-wearing the neck supporter. Overall findings verified that the neck supporter might help to prevent neck-related MSDs based on the current study.

• PNF and Movement
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• v.21 no.1
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• pp.87-94
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• 2023

Purpose: The present study aims to investigate the effects of a diagonal exercise pattern on selective activation of the upper extremity muscles using both normalization and isolation methods. Methods: In total, 17 asymptomatic subjects participated in this study. During the two diagonal patterns of exercise (diagonals 1 and 2), muscular activities of the upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), anterior deltoid (AD), and infraspinatus (IS) were measured. The collected data were analyzed in two ways, according to the dominance of muscle activities (%Isolation) and according to normalized activities (%MVIC). Results: There were significant differences in LT, SA, AD, and IS between %MVIC and %Isolation (p<0.05), and the diagonal 1 pattern of exercise showed significantly more LT activities compared with the diagonal 2 pattern (p<0.05). Further, except for LT, there were no significant differences in muscle activities between the diagonal 1 and 2 exercises. Conclusion: The present study suggests that a diagonal pattern of exercise is advantageous for strengthening shoulder muscles, but caution is needed when applying to patients requiring selective strengthening. Regarding both the concentric and eccentric phases of exercise, there was no significant difference in muscular activation, except in LT, between the two diagonal patterns of exercises.

• 한국체육학회지인문사회과학편
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• v.54 no.1
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• pp.515-525
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• 2015

The purpose of this study was to compare muscular activities according to the mastery of Taekwondo kicking motions with the subjects of 8 demonstration team members and 8 undergraduates in Taekwondo major at University. The muscles mainly used for Taekwondo's front kick, tornado kick, or turning hook kick are total 8 trunk muscles and 8 lower limb muscles of the kicking foot as well as the supporting foot. Analyzing the muscular activities of those areas comparatively, the study has reached the following results. At the front kick, non-experts showed higher lower abdominal muscle, biceps thigh muscle activity of the kicking foot and lateral gastrocnemius muscle activity of the supporting foot but lower 2 spinals muscular activity than experts. At the tornado kick (or turning kick), in the turning motion, experts indicated higher activity in biceps muscle of thigh and spinalis than non-experts whereas in the kicking motion, they didn't show the difference between groups except biceps thigh muscle activity. At the turning hook kick, non-experts indicated higher lateral gastrocnemius muscle activity of the kicking foot and quadricpes femoris muscle activity of supporting foot muscular activity than experts. In summary, experts tend to use their trunk in the turning motion for rapid turning and show rather low muscular activity of their kicking foot. However, non-experts indicate high muscular activity in their kicking foot and supporting foot, which means to maintain balance in the kicking motion, they tend to make use of their lower limb more than trunk muscle, and it leads to an inefficient motion.

• Journal of the Korean Society of Clothing and Textiles
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• v.17 no.2
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• pp.197-206
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• 1993

We studied relation between the clothing pressure applied by foundations(waist nipper, girdle, body suit) on the waist of bodies and muscular activity, feeling of tightness. The main results were summerized as follows ; 1. Clothing pressure applied by foundations was high in order of girdle>waist nipper>body suit, also clothing pressure was higher back than front and side, sitting on the chair than standing posture, ventral flection than repose. Individual differences, even if size of body was equal, were shown in clothing pressure applied by foundations with subcutaneous fat's amount in measuring region. 2. The muscular activity of rectus abdominis than obliquus externus abdominis was more affected by foundations in all kinds of postures and motions. Amplitude of electromyogram was high sitting on the chair than standing posture, but there was little difference with motion variation. The wearing girdle strongly affected on the muscular activities of rectus abdominis and obliquus externus abdominis as compared with waist nipper and body suit. 3. The value for feeling of tightness by wearing waist nipper was higher than girdle and body suit. Also the case when sitting on the chair and ventral flection, the value for feeling of tightness was high. When the foundations were on the body, most tightened on the region of the body was anterior abdominal region.

• Journal of the Ergonomics Society of Korea
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• v.20 no.2
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• pp.71-82
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• 2001

Twisting posture in lifting tasks has been identified as a risk factor of low back pain. However, it has been usually estimated in terms of compressive stress or muscular activity. Thus, this study was conducted to predict the influence on muscular fatigue during lifting simulation. Fifteen young and healthy subjects were recruited and performed isometric trunk exertions during upright standing, two-level flexions and five-level asymmetric twisting conditions. EMG signals from five primary trunk muscles in right part of body were collected during 20sec for 45 different lifting conditions. RMS(root mean square) and MPF(mean power frequency) parameters were used to analyze the EMG signals. Twisting postures were significant in right erector spinae(ERSR), right latissimus dorsi(LATR), right internal oblique(INOR) for muscular activities. Especially, when trunk was $30^{\circ}$ CCW twisting posture. ERSR and INOR activities increased respectively by 11% and 3%. Regarding the trunk muscle fatigue, we found that MPF shifts in twisting posture increased 2.3 and 2.6 times for ERSR and INOR muscles respectively. Therefore, It is probable for workers to suffer from low back disorders when they were exposed to a extreme twisting posture during prolonged lifting. This study suggests NIOSH(National Institute for Occupational Safety and Health) lifting equation needs the time-duration multiplier in addition to asymmetric multiplier.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.713-714
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• 2007