• 대한의용생체공학회:의공학회지
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• 제28권5호
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• pp.636-646
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• 2007

Adequate postural control depends on the spatial and temporal integration of vestibular, visual, and somatosensory information. Especially, the musculoskeletal function is essential to maintain the postural control. The experimental studies was performed on the muscular activities in the lower extremities during maintaining and moving exercises on an unstable platform with Magneto Rheological(MR) dampers. The unstable platform of the developed system was controlled by electric currents to the MR dampers. A subject executed the maintaining and moving exercises which are presented through the display monitor. The electromyographies of the eight muscles in lower extremities were recorded and analyzed in the time and the frequency domain: the muscles of interest were rectus femoris(RF), biceps femoris(BF), tensor fasciae latae(TFL), vastus lateralis(VL), vastus medialis(VM), gastrocnemius(Ga), tibialis anterior(TA), Soleus(So). The experimental results showed that the muscular activities differed in the four moving exercises and the nine maintaining exercises. For the anterior-posterior pattern, the TA showed highest activities; for the left-right pattern, the TFL; for the 45, $-45^{\circ}$ pattern, the TFL and TA. Also, the rate of the increase in the muscular activities were affected by the condition of the unstable platform with MR dampers for the maintaining and moving exercises. The experimental results suggest that the choice of different maintaining and moving exercises could selectively train different muscles in various intensity. Futhermore, the findings suggested that the training using this system can improve the ability of postural control.

• International Journal of Advanced Culture Technology
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• 제8권3호
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• pp.307-315
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• 2020

The physique and health status of Chinese college students have received a generous concern in recent years. The physical condition of Chinese college students is not good and this phenomenon is especially obvious among female college students, which has been an disputable fact. This study starts from exercise intervention to study the concrete influence of taijiquan (a kind of traditional Chinese shadow boxing) and five-animal exercises on human body balance ability; the study uses experimental apparatus to measure the specific impact of exercise intervention on human body balance ability; meanwhile, the study also applies data analysis to longitudinally study whether the two studied sports items affect body balance, and whether there is difference in terms of the influence of two sports items on human body balance ability. The conclusions are as follows: firstly, 24-style taijiquan and five-animal exercises can improve ankle muscle strength, and the focus and degree of the improvement are different; secondly, five-animal exercises have a better improvement effect on the flexor and extensor muscles of ankle joint and 24-style taijiquan is in the second place. Moreover, compared with 24-style taijiquan, there is no significant difference in terms of the improvement caused by five-animal exercises; thirdly, 24-style taijiquan has a better effect on the improvement of internal rotation and evertors muscle strength. Compared with 24-style taijiquan, five-animal exercises have no significant difference in terms of the improvement degree.

• 대한정형도수물리치료학회지
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• 제23권1호
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• pp.23-30
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• 2017

Purpose: The purpose of this study was to investigate the effect of transverse abdominis ratio and balance ability during bridge exercises on different support surface. Methods: The subjects were 20 students at G University. Ultrasound equipment was used to measure the transverse abdominisratio and the computerized balance measurement equipment was used to measure the balance ability before and after bridge exercises on different support surface. Results: Transverse abdominis ratio change between the groups was a significant difference only in the unstable support surface training group (p<.05). Normal standing eye close balance ability change between the groups was significantly different only in the unstable support surface training group (p<.05). The changes in the transverse abdominis ratio after 7 days of exercise and 14 days after exercise were significantly different between the groups (p<.05). Normal standing eye close balance ability showed a significant difference at 7 days after exercise and 14 days after exercise (p<.05). Conclusions: It is more effective to balance ability and ratio of the transverse abdominis when bridge exercises on an unstable support surface than to perform bridge exercises on a stable support surface. Therefore, we propose an effective program for patients with instability of the lumbar in clinical practice. bridge exercises on different support surface.

• 한국운동역학회지
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• 제21권1호
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• pp.107-114
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• 2011

Closed kinematic chain exercises such as squatting have been widely indicated for knee rehabilitation in patients with patellofemoral disorders such as osteoarthritis and patellofemoral pain. Patellofemoral disorders are thought to be associated with abnormal patellar kinematics. In addition, the Q-angle may be undervalued in patients with patellofemoral pain and a laterally displaced patella. The purpose of this study was to assess patellar kinematics and the Q-angle during double-leg semi-squat and wall-slide semi-squat exercises. In this study, 28 asymptomatic subjects(16 male, 12 female) were assessed. Patellar tilt, patellar spin, and Q-angle were recorded using a motion analysis system during double-leg semi-squat and wall-slide semi-squat exercises. The Q-angle and patellar tilt were significantly increased, whereas patellar spin was significantly decreased, at $45^{\circ}$ of knee flexion compared with $0^{\circ}$. No differences were observed for the Q-angle, patellar tilt, and patellar spin during double-leg semi-squat and wall-slide semi-squat exercises. However, a significant interaction was observed between squat type and knee angle for patellar spin. We found that the patella is laterally tilted during semi-squat exercises and that there was no difference in patellar tracking between knee flexion during double-leg semi-squat and wall-slide semi-squat exercises.

• 대한통합의학회지
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• 제4권4호
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• pp.101-108
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• 2016

Purpose : The purpose of this study was to determine the effect of selective thoracic extensor strengthening exercises in the sitting position using a foam-roller by investigating the electromyographic(EMG) activities of the thoracic and lumbar extensors. Methods : Eighteen healthy subjects with no medical history of back pain were recruited. EMG activity was recorded from thoracic extensor(TE) and lumbar extensor(LE) while subjects performed three thoracic extension exercises: prone thoracic extension(PTE), prone thoracic extension with abdominal draw-in maneuver(PTE-ADIM), and sitting thoracic extension using a foam-roller(STE). TE and LE EMG activity, and TE/LE EMG activity ratio were analyzed by one-way repeated-measures analysis of variance(ANOVA). Where a significant difference was identified, a Bonferroni correction was performed(p<.017, .05/3). Results : TE and LE EMG activity, and TE/LE EMG activity ratio differed significantly among the three exercises(p<.05). Post hoc pair-wise comparison with Bonferroni correction showed that TE muscle activity in the STE exercise was significantly different from PTE and PTE-ADIM exercises(p<.017). There was no significant difference between TE muscle activity for PTE and PTE-ADIM exercises(p>.017). LE muscle activity and TE/LE ratios were significantly different among the three exercises p<.017). Conclusion : TE/LE ratio showed superior selective thoracic extensor strengthening for the STE exercise than PTE and PTE-ADIM exercises. Therefore, we recommend STE exercise for selective thoracic extensor strengthening.

• 대한물리의학회지
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• 제15권3호
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• pp.11-20
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• 2020

PURPOSE: Excessive activity of the upper trapezius (UT) muscle contributes to a rounded shoulder posture (RSP) through abnormal rotation of the scapula that weakens the lower trapezius (LT) and serratus anterior (SA) muscles. This study compared the effects of two arm-lifting exercises with and without the use of a Thera-band on the activities of LT, SA, and UT muscles, and the LT/UT and SA/UT activity ratio in subjects with a rounded shoulder posture. METHODS: Sixteen subjects with RSP participated in this study. All subjects performed arm-lifting (AL), diagonal arm-lifting (DAL), arm lifting with isometric adduction (ALIA), and diagonal arm-lifting with isometric adduction (DALIA) exercises. The surface electromyography data, LT, SA, UT, and the LT/UT and SA/UT activity ratios were measured. A paired t-test was used to compare the differences between two arm-lifting exercises and two arm lifting with isometric adduction exercises. RESULTS: In ALIA and DALIA exercises, the UT muscle activity decreased significantly, whereas the LT/UT, SA/UT activity ratio increased significantly. The activity of SA muscle increased significantly more with DALIA than that with DAL. CONCLUSION: Arm-lifting exercises using a Thera-band can be implemented as an effective way to reduce the UT overactivity and increase the SA activity and LT/UT, SA/UT activity ratio in subjects with RSP.

• The Journal of Korean Physical Therapy
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• 제30권5호
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• pp.166-172
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• 2018

Purpose: This study compared the different sling and resistance exercises on pelvic rotation during active straight leg raises (ASLR) and on pain in patients with chronic low back pain (CLBP). Methods: Twenty subjects were divided randomly into a sling group (SG) and a resistance exercise group (REG). Internal oblique (IO), external oblique (EO), rectus abdominis (RA), and rectus femoris (RF) muscle activity; pelvic rotation angle during ASLR; and visual analogue scale, pressure pain threshold were measured. Sling and resistance exercises were then performed for 30 minutes and the measurements taken again. Results: Both groups showed significantly lower RF muscle activity and significantly higher EO and IO muscle activity (p<0.05). The RA muscle activity decreased significantly in the SG, but increased significantly in the REG (p<0.05). The pelvic rotation angle was significantly lower in the SG (p<0.05). The pain press threshold increased significantly in both groups (p<0.05). The visual analogue scale decreased significantly in the SG (p<0.05). Conclusion: Both exercises appear to be beneficial for modifying the muscle activity and pain control in the intervention of CLBP. On the other hand, the sling was more effective in increasing the pressure threshold than resistance exercise, and the pelvic rotation angle was reduced. Therefore, both exercises can help patients with CLBP change their muscle activity and control pain. CLBP patients should use a sling for short periods of time to learn to reduce the pain and control pelvic rotation.

• The Journal of Korean Physical Therapy
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• 제32권2호
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• pp.94-100
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• 2020

Purpose: This study examined the effects of the abdominal hollowing technique applied during plank exercises at different shoulder angles between the ground and the humerus on the abdominal muscle activity Methods: The subjects were 36 male volunteers. They were randomized to perform plank exercises or plank exercises using the hollowing technique at 80˚, 90˚, 100˚, and 110˚ between the ground and the humerus. The abdominis muscles were measured using a surface electromyogram. Independent t-tests examined the changes in the activity of these muscles according to the two exercise methods at each angle. The changes in muscle activity were examined according to the selected angles by one-way analysis of variance. Results: The activity of abdominal muscles was investigated according to the angle between the ground and the humerus during the plank exercise. As a result, the muscle activity increased significantly with decreasing angle in the rectus abdominis, external oblique, and internal oblique·transverse abdominis muscles (p<0.05). In terms of the changes in abdominal muscle activity after hollowing plank exercises at the given angles between the ground and the humerus, an increase in angle resulted in a statistically significant increase in the rectus abdominis muscle activity (p<0.05). The activities of the rectus abdominis, external oblique, and internal oblique/transverse abdominis muscles after hollowing plank exercises showed statistically significant increases (p<0.05) compared to those after plank exercises. Conclusion: The hollowing technique and the increase in the angle between the ground and the humerus may be an effective exercise method for increasing the muscle activity of the abdominis muscles.

• The Journal of Korean Physical Therapy
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• 제17권3호
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• pp.297-310
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• 2005

Open kinetic chain exercise has lost favour in rehabilitation after cruciate ligament reconstruction due to concerns that this exercise is harmful to the graft and will be less effective in improving function. Therefore rehabilitation has focused over the past decade on closed kinetic chain exercise. Open kinetic chain and closed kinetic chain exercises were compared for their effects on proprioception, muscle strength and knee instability in the early period of cruciate ligament reconstruction rehabilitation. The study subjects were 14 patients in 28weeks from cruciate reconstruction surgery(11 male, 3 female; mean age = 44.36 years). Closed kinetic chain exercise group used ball, balance pad and air cushion, to perform weightbearing exercises and the open kinetic chain exercise group used elastic rope and N-K table, to perform non-weightbearing exercises. Between tests, subjects trained 5 times per week for 2 weeks. Statistical analysis was by Wilcoxon signed rank test and Mann Whitney U test. In result, this study shows that both open and closed kinetic chain exercise programs lead to an improved muscle strength and Lysholm score. But there was no improvement in proprioception at both exercises. Closed versus open kinetic chain exercise in early period of rehabilitation after cruciate ligament reconstruction surgery do not differ in their effects on knee proprioception, muscle strength and instability. But the effect of closed kinetic chain exercises was showed more improvement than open kinetic chain exercises between pre-post exercises. Therefore further study is required to assess effect of both groups in more long period.

• 한국전문물리치료학회지
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• 제8권2호
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• pp.65-72
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• 2001

The purpose of this study was to investigate the effect of knee exercises on the onset times of vastus medialis oblique muscle (VMO) and vastus lateralis muscle (VL) and in healthy subjects. Fifteen subjects (7 men, 8 women) in a mean age of 26.4 years participated in the study. Electromyographic (EMG) signals were recorded from the VMO and VL under four exercises. Knee exercises consisted of open kinematic terminal knee extension, straight leg raising, isometric hip adduction exercise, and closed kinematic terminal knee extension. No significant differences were found in the onset times of EMG activities of VMO and VL in the four exercises. There were also no significant differences among the exercises. These results coincided with previous studies that found no difference between onset of VMO and VL. However, it is difficult to say that there is no difference between onset of VMO and VL in healthy subjects. To confirm this results, further researches that follow same on set determination metod and exercises are needed. Not only is the study of onset time of muscle needed, but also the studies of the amount of activation and the rate of increase of muscle activation are needed.