• Journal of International Academy of Physical Therapy Research
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• v.11 no.2
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• pp.2071-2076
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• 2020

Background: Based on the understanding of the muscle activation relationship between the infraspinatus and posterior deltoid muscles to according to the angle of motion during external rotation on glenohumeral joint, effective shoulder joint strengthening exercise for the prevention and rehabilitation of shoulder injury due to muscle strength imbalance can be performed by achieving the ideal muscle activity ratio during exercise. Objectives: To compare and analyze the muscle activation changes and activity ratio of the infraspinatus and posterior deltoid muscles according to the glenohumeral external rotation angle. Design: Quasi-randomized trial. Methods: The study included 48 healthy male and female adults who provided informed consent for participation in the study. All the subjects performed isometric glenohumeral external rotation by setting the angle of motion to 30°, 45°, and 60° using a 5 kg resistance weight pulley. On surface electromyography, the differences in muscle activation and activity ratio between the infraspinatus and posterior deltoid muscles were investigated. Results: A significant difference in muscle activation was found in the comparison between the infraspinatus and posterior deltoid muscles according to the glenohumeral external rotation angle (P<.05). The muscle activation levels of the infraspinatus and posterior deltoid muscles were highest at the external rotation angles of 30° and 60°, respectively. The muscle activity ratio between the infraspinatus and posterior deltoid muscles also showed a significant difference (P<.05) and was highest at the shoulder external rotation angle of 30°. Conclusion: The findings of this study suggest that muscle activity is the highest at the shoulder external rotation angle of 30° in healthy individuals.

• Journal of Biomedical Engineering Research
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• v.40 no.6
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• pp.223-229
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• 2019

The number of knee-related disease patients and knee joint surgeries is steadily increasing every year, and for knee rehabilitation training for these knee joint patients, it is necessary to strengthen the muscle of vastus medialis and quadriceps femoris. However, because of the cost and time-consuming difficulties of receiving regular hospital treatment in the course of knee rehabilitation, we developed knee exoskeleton using rapid prototype for knee rehabilitation with feedback from the electromyogram (EMG) and inertia motion unit (IMU) sensor. The modules was built on the basis of EMG and an IMU sensor applied complementary filter, measuring muscle activity in the vastus medialis and the range of joint operation of the knee, and then performing the game based on this measurement. The IMU sensor performed up to 97.2% accuracy in experiments with ten subjects. The functional game contents consisted of an exergaming platform based on EMG and IMU for the real-time monitoring and performance assessment of personalized isometric and isotonic exercises. This study combined EMG and IMU-based functional game with knee rehabilitation training to enable voluntary rehabilitation training by providing immediate feedback to patients through biometric information, thereby enhancing muscle strength efficiency of rehabilitation.

• Korean Journal of Exercise Nutrition
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• v.16 no.1
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• pp.43-50
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• 2012

This study was designed to investigate the effect of vibratory stimulation on recovery of muscle function from delayed onset muscle soreness (DOMS). Volunteers performed 3 set of 70 % maximal voluntary eccentric muscle contraction and induced DOMS. volunteers were allocated to one of three treatment group after DOMS : group I (control), group II (ultrasound), group III (vibration). Maximal Voluntary Isometric Contraction (MVIC), Visual Analog Scale (VAS), Range Of Motion (ROM), Root Mean Square (RMS), Median frequency (MDF), Blood Serum Creatine Kinase (CK), Lactic dehydrogenase (LDH) were recorded at baseline, and 24, 48, 72 hours post-exercise. In MVIC measurement, there was a statistically significant difference in group III compared to group I (p < .05). In VAS measurements, there were a statistically significant difference in group II and III compared to group I (p < .05). In ROM measurement, there was a statistically difference in group II and III compared to group I (p < .05). In Muscle Volume with Ultrasonography measurement, there was no statistically significant difference in any groups (p > .05). In RMS and MDF measurement, there were a statistically significant difference in group II and III compared to group I (p < .05). In Blood samples of CK and LDH measurements, There were no statistically significant difference in any groups (p > .05). From the above result, Vibratory stimulation had a positive effect on recovery of muscle function from delayed onset muscle soreness. Further studies should be undertaken to ascertain the more effectiveness of vibratory stimulation and may be a promising treatment modality.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.4
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• pp.41-50
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• 2023

Purpose : The aim of study was to determine the effect of lower trapezius muscle strengthening exercises on the height of rounded shoulder posture and muscle activity in patients with rounded shoulder posture. Methods : Thirty-one subjects with rounded shoulders were selected and assigned, with the use of a random number table, to an experimental group (EG, n=16) that received resistance exercises of the trapezius (lower) muscles or a control group (CG, n=15) that received isometric exercises of the lower trapezius muscles. In the EG, with the subject in a prone position, both arms were abducted at the angles suggested for each posture (145 °, 45 ° abduction), with the hands holding dumbbells to assume a functional posture. The CG performed only isometric exercises without dumbbells in the same conditions. At the start signal, with the thumb raised, the arm was raised to the level of the ear. Both groups were assessed by the height of the rounded shoulder posture (RSP) and muscle activity (EMG). The intervention was performed three times a week. Results : The RSP significantly decreased during the intervention period in both the EG and CG (p<.05), and a significant difference was determined between the RSP of the two groups (p<.05). In the EG, the EMG significantly increased during the intervention period (p<.05), but the CG did not show any significant increase (p>.05). The final EMG was significantly higher in the EG than in the CG (p<.05). Conclusion : Both the EG and CG showed positive improvement in rounded shoulder posture during the intervention period. In particular, lower trapezius resistance exercise appears to reduce shoulder height and positively affects the activity of muscles around the shoulder.

• Journal of International Academy of Physical Therapy Research
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• v.1 no.2
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• pp.185-191
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• 2010

Background: This study investigated effective posture for gluteus medius rehabilitation training and effects of isometric muscle activity by electrophysiology through EMG while performing dynamic isotonic behavior of weight placed differently on upper limbs. Method: 16 healthy male subjects 20 to 29 years of age volunteered for the study. Lateral stabilizer right gluteus medius activity was assessed using EMG while the right lower extremity maintains single limb support, and the left upper extremity elevation movement maintains 5 seconds without load, 1RM to 1 repetition, 5RM to 5 times, 10RM to 10 times, 5RM and 10RM maintain 5sec. Results: Comparison of the mean value of EMG data showed a statistically more significant difference in upper extremity elevation movement on opposite upper extremity added weight than one that was not added on a single limb weight bearing posture(p>.05). Weight supported side gluteus medius activity for 1RM, 5RM, 10RM weight difference and movement repetition did not differ(p>.05). Comparison in maximum value showed statistically significant differences in not adding weight on upper limb elevation exercise and 1RM, 5RM, 10RM repeated behavior. Elevation behavior and repetition appeared over 70% of MVIC. Conclusion: Unilateral weight bearing stance added weight in the opposite upper limb elevation movement was an indirect exercise to effectively stimulate gluteus medius activity. Applying various added weight will have effective exercise on the early stages of rehabilitation because activity gluteus medius did not differ through added weight.

• The Journal of Korean Physical Therapy
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• v.14 no.3
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• pp.136-144
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• 2002

The Purpose of this study was to compare the lumbar strength and lumbar flexor/extensor ratio between spondylolisthesis and herniated disc patients. The patients who had a subacute low back pain have been proved to each disease through MRI and we measured the maximal isometric strength of all patients(28) through MedX lumbar extension machine(Ocala, FL). In all patients, males had higher lumbar extensor strength than that of females. Especially, the spondylolisthesis patients had lower lumbar extensor strength than that of herniated disc patients. The statistical significant(p<.05, p<.01) differences were manifested in $48^{\circ},\;60^{\circ}\;and\;72^{\circ}$ between male groups. Also the statistical significant (p<.05) differences were manifested in $60^{\circ}\;and\;72^{\circ}$between female groups. In the lumbar flexor/ extensor ratio, the males of spondylolisthesis groups represented the functional weakness in the flexed portion of the range of motion, and the females of spondylolisthesis and the all patients of herniated disc represented the functional weakness in the extended portion of the range of motion. In conclusion, we may propose the program such that the spondylolisthesis males must increase the ratio of extended portion exercise, and the spondylolisthesis females and herniated disc patients must increase the ratio of flexed portion exercise.

• Physical Therapy Rehabilitation Science
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• v.10 no.4
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• pp.487-492
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• 2021

Objective: This study aimed to identify the effects of assuming two types of posture (standing and kneeling) during squat exercise on lower body muscle activity. Design: Cross-sectional study Methods: Twenty-five healthy adults (18 men and 7 women) were instructed to perform the squat exercises while assuming two types of posture (standing and kneeling). EMG (Electromyography) data (% maximum voluntary isometric contraction) were recorded three times from the rectus femoris (RF), gluteus maximus (GMax), gluteus medius (GMed) and biceps femoris (BF) of participant's dominant side and the mean values were analyzed. Results: During the squat exercise with all postures, there was statistically significant difference on rectus femoris, gluteus maximus, gluteus medius, and biceps femoris muscle activity (p<0.05). The results showed that, there was significantly greater rectus femoris, gluteus medius, and biceps femoris muscle activity in standing posture than in kneeling position (p<0.05). However, the gluteus maximus muscle activity was significantly greater with kneeling posture compared to standing posture (p<0.05). Conclusions: With standing posture, it is showed that rectus femoris, gluteus medius, and biceps femoris muscle activity was greater than kneeling position. While the gluteus maximus muscle activity with standing posture was less than with kneeling posture. Therefore, it is considered that this study can be used as a selective indicator of exercise posture for strengthening specific muscle or weakness caused by paralysis.

• Journal of the Korea Convergence Society
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• v.10 no.2
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• pp.309-313
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• 2019

This study examined the response of the EMG of URA, LRA, IO, EO and RFM of various types of abdominal motion (crunch, spine V-up on ball, prone V-up on slide board, prone V-up on TRX, and prone V-up power wheel). The subjects performed anisometric contact of abs during these exercises. Tests have shown that there were no statistically significant differences between EO, URA and LRA between any movements. However, during the inspection of IO, the positive-wawed V-up motion showed significantly greater muscle activity than during the slide movement. Also, EMG activity during crunch was significantly lower than any other five exercises. These results indicate that in the implementation of equilateral absolutism, the equipment-free based exercise gives an impetus similar to equipment-based exercise. Abdominal muscle tissue is considered one of the five components that make up an individual's core. The abdominal muscles also ensure proper functioning of the lumbar spine. Although all abdominal muscles contribute to lumbar stabilization, TA & IO has been shown to perform major stabilizers.

• The Korean journal of sports medicine
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• v.36 no.4
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• pp.197-206
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• 2018

Purpose: This study analyzed the muscle activity changes induced by motions of reaching forward and chest expansion that were examined from the bilateral muscles with rectus abdominis, external oblique, multifidus, and longissimus thoracic using Pilates cadillac instrument. Methods: Nine young adult women, who have no musculoskeletal disorder and any of chronic diseases, were participated. Surface electromyography system was used for recording of all signals produced by muscles, and then normalized as percentage of maximum voluntary isometric contraction (%MVIC). The paired t-test and repeated measures of analysis of variance was performed. Results: Reaching-forward motion showed a higher muscle activity from non-dominant external oblique muscle than that of the chest-expansion motion. During both reaching-forward motion and chest-expansion motion, MVIC values collected from dominant side of external oblique muscle were shown a significantly lower than the values obtained from non-dominant side (p<0.05). Conversely, %MVIC values in external oblique muscle collected from dominant side showed a significantly higher than the values obtained from non-dominant side of the same oblique muscle (p<0.05). Reaching-forward motion was caused a higher %MVIC on non-dominant external oblique muscle than that of the chest-expansion motion (p<0.05). Regardless of dominant or non-dominant sides, external oblique muscle was shown the highest activation rate of all the other muscles during reaching forward action, and longissimus thoracic muscle was shown the highest activation rate of all the other muscles during chest expansion action. Conclusion: Reaching-forward motion is suitable for activating an external oblique muscle, and chest-expansion motion is an effective enough in activating of longissimus thoracic muscle.

• PNF and Movement
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• v.18 no.3
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• pp.323-331
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• 2020

Purpose: This study was conducted to determine the effects of motion taping on muscle activity and the WOMAC in a rehabilitation exercise program for elderly women with knee joint osteoarthritis. Methods: The subjects were 28 elderly women aged over 65 years with knee joint osteoarthritis. The subjects were divided into two groups: one experimental and one control group. During the study period, a total of 26 patients completed the experiment, with one drop each from the experimental group and control group. The experimental group applied motion taping and conducted a rehabilitation exercise program. The control group experienced a rehabilitation exercise program without motion taping. The rehabilitation exercise program consisted of warm-up exercises, maximum isometric exercises, the range of motion of the joints, and leg stretching exercises. The intervention was conducted three times a week for six weeks. To investigate the effects of the intervention, muscle activity and the WOMAC were measured. The WOMAC is a tool that can be used to evaluate the pain, stiffness, and physical function of osteoarthritis patients; it has 29 items in three areas. Results: The change in muscle activity according to the intervention showed a statistically significant increase in both the experimental group and control group. The WOMAC also showed statistically significant changes in terms of pain, stiffness, and physical function in both the experimental and control groups. The experimental group showed a greater functional improvement than the control group. Conclusion: For older women with osteoarthritis of the knee, a rehabilitation exercise program is a good intervention. When motion-taping is applied, it is considered to be an intervention program that can be expected to have a better effect on knee joint osteoarthritis.