• Biomedical Engineering Letters
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• v.8 no.4
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• pp.345-353
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• 2018

This study suggested a new EMG-signal-based evaluation method for knee rehabilitation that provides not only fragmentary information like muscle power but also in-depth information like muscle fatigue in the field of rehabilitation which it has not been applied to. In our experiment, nine healthy subjects performed straight leg raise exercises which are widely performed for knee rehabilitation. During the exercises, we recorded the joint angle of the leg and EMG signals from four prime movers of the leg: rectus femoris (RFM), vastus lateralis, vastus medialis, and biceps femoris (BFLH). We extracted two parameters to estimate muscle fatigue from the EMG signals, the zero-crossing rate (ZCR) and amplitude of muscle tension (AMT) that can quantitatively assess muscle fatigue from EMG signals. We found a decrease in the ZCR for the RFM and the BFLH in the muscle fatigue condition for most of the subjects. Also, we found increases in the AMT for the RFM and the BFLH. Based on the results, we quantitatively confirmed that in the state of muscle fatigue, the ZCR shows a decreasing trend whereas the AMT shows an increasing trend. Our results show that both the ZCR and AMT are useful parameters for characterizing the EMG signals in the muscle fatigue condition. In addition, our proposed methods are expected to be useful for developing a navigation system for knee rehabilitation exercises by evaluating the two parameters in two-dimensional parameter space.

• The Journal of Korean Physical Therapy
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• v.33 no.1
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• pp.40-46
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• 2021

Purpose: This study compared the muscle activity of the lower limb according to the three types of fixed angles of the ankle joint during a lunge exercise. Methods: Twenty healthy subjects performed the lunge motion in a trial including the three types of fixed angle. The lunge motion with a neutral, 20° dorsiflexion, and 20° plantarflexion of the ankle joint were randomized and measured repeatedly. The muscle activity of the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF), and semitendinosus (ST) was measured by surface electromyography. Results: In the change in ankle joint angle, the RF, VL, BF, and ST muscle activity showed significant differences (p<0.05). In the 20° dorsiflexion position, the muscle activity of VL, BF, and ST showed a significant decrease compared to that in the neutral position (p<0.017). The muscle activity of RF and VL in the neutral position was greater than that in the 20° plantarflexion position (p<0.017). Only the muscle activity of the BF in the 20° plantarflexion position was significantly greater than the 20° dorsiflexion position (p<0.017). Conclusion: These results revealed a difference in the muscle activity of lower extremities in the proximal region according to the angle of the ankle joint during the lunge.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.2
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• pp.49-56
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• 2020

PURPOSE: This study examined the difference in muscle activity of the trunk and legs during flat walking with or without an abdominal drawing-in maneuver. METHODS: This study was conducted on 15 healthy males and eight females who were attending D University in Busan. This experiment was conducted after 15 minutes of abdominal drawing-in training using a pressure biofeedback unit before the experiment, and the difference in the muscle activity of the trunk and legs during flat walking with or without an abdominal drawing-in technique was investigated. Surface electromyography was used, and the electrode attachment site was the right sternocleidomastoid muscle, splenius capitis muscle, rectus abdominis muscle, external abdominal oblique muscle, transverse abdominis muscle, erector spinae muscle, vastus medialis muscle, and vastus lateralis muscle (TM DTS, Noraxon, USA). The data were analyzed statistically using a paired t-test on SPSS version 18.0 (IBM). RESULTS: The muscle activity of the rectus abdominis muscle, external abdominal oblique muscle, transverse abdominis muscle, vastus medialis muscle were increased significantly and maintained more than walking without maintaining an abdominal drawing-in maneuver (p < .05). Moreover, muscle activity of the erector spinae muscle was decreased significantly and maintained more than walking without maintaining an abdominal drawing-in maneuver (p < .05). CONCLUSION: Maintaining an abdominal drawing-in maneuver during flat walking is more effective during walking training.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.3
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• pp.131-140
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• 2022

Purpose : Although many studies have explored the effect of seating side angles on the spinal curve and surrounding muscles during seating, only a few studies have investigated the effect of different seating face angles on different lower limb and deep trunk muscles. Therefore, this study investigated the effects of seating surface angles (0 degrees, 10 degree anterior, and 10 degree rear) on lower extremity and deep trunk muscles in healthy adults. Methods : Thirty people were asked to sit once on each seating surface three times during the day, and their muscle thicknesses were measured by ultrasound while sitting. The method of sitting was the same when sitting on the three seating surfaces. Results : From the comparison results of the muscle thicknesses according to the seating surface angles, a significant difference existed in the muscle thicknesses of the vastus medialis, vastus medialis oblique, vastus intermedius, soleus and gastrocnemius (p<.05). However, no significant difference was found in the transversus abdominis, internal obliques, rectus femoris and vastus lateralis (p>.05). Conclusion : Our findings revealed that the lower back load decreases, the leg load increases, and the legs specific muscles are affected as the body tilts forward when sitting on the seating surface inclined forward. Therefore, it is possible to suggest a forwardly inclined seating surface that reduces lower back loads and utilizes the posture-maintaining muscles of the legs when sitting in a person with a poor sitting posture or lower back pain at ordinary times.

• Journal of Digital Convergence
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• v.11 no.8
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• pp.265-272
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• 2013

The purpose of this study was to provide a foundation for the methods of stretching in sports activities. The subjects were normal adults, the applied exercise was dynamic and static stretching and the research methods were measuring the jump height and muscle activity during jumping with subsequent data comparison and analysis. Twenty normal adults were randomly divided into 2 groups, and each group performed dynamic or static stretching. Jump height and the vastus lateralis and gastrocnemius muscle activities were measured during jumping, which was performed immediately before and after stretching. Statistical analysis was performed using an analysis of covariance. The results indicated that dynamic stretching was more effective than static stretching with respect to both jump height (p<.05) and muscle activity of the vastus lateralis (p<.05). Consequently, it was believed that dynamic stretching should be applied as a warm-up exercise for athletes who need to build and maintain high muscle strength.

• Journal of Society of Preventive Korean Medicine
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• v.11 no.2
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• pp.121-132
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• 2007

The purpose of this study is to find out the effects of taping therapy on muscle activities between the group of taping therapy treatment and control group before or after exercises. The subjects are 18 S college's healthy male students who do not have any problems in the legs and could bend the knee joint normally. Considering physique, condition of health and capacity for locomotion, 3 groups of each 6 persons for the experimentation were classified. Three groups composed of control group without taping therapy treatment for control group, group I with taping therapy treatment only before the experimentation and group II with taping therapy treatment during 24 hour. before and after the experimentation. EMG MP150 was used to evaluate the parameter of the lower leg's muscle activities the exercise before 5 min. after 10 min. and after 24 hour. for the experimentation. Compared with control group, group I and group II had more increased muscle activities in vastus lateralis and rectus femoris and was statistically significant. And group I and group II also had more increase in muscle activities than control group in vastus medialis, although there was no statistically significant. We found that taping therapy increased muscle activity positively. The application of taping therapy could be used not only for preventive effects for sports man but also therapeutic effects for general people.

• The Journal of Korean Physical Therapy
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• v.27 no.4
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• pp.190-195
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• 2015

Purpose: The aim of this study was to determine the effects of isokinetic eccentric training (IET) on lower extremity muscle activation and walking velocity according to slow velocity and fast velocity of isokinetic eccentric training in stroke patients. Methods: Thirty subjects were randomly divided into three groups: experimental group I (n=10), group II (n=10), and control group III (n=10). Each group was provided intervention under three conditions, as follows: isokinetic eccentric training + slow velocity (group I), isokinetic eccentric training + fast velocity (group II), and sit to stand training (group III). The training program was conducted for eight weeks (five times per week; 30 minutes per day). Subjects were measured on lower extremity muscle (vastus lateralis, vastus medialis, gastrocnemius) activation and walking velocity. Analysis of covariance (ANCOVA) were performed for comparison of lower extremity muscle activation and walking velocity between different intervention methods. Results: Significant difference in lower extremity muscle activation and walking velocity was observed in experimental group I and group II compared with the control group III (p<0.01). Results of post-hoc analysis showed a significant in lower extremity muscle activation and walking velocity in group I compared with group II and group III. Conclusion: Findings of this study suggest that slow velocity and fast velocity using isokinetic eccentric training may have a beneficial effect on improvement of lower extremity muscle activation and walking velocity in stroke patients.

• Journal of Korean Physical Therapy Science
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• v.7 no.2
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• pp.697-709
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• 2000

The purpose of this study was to evaluate the effectiveness of ElectroMyoscope(Electro_Acuscope and Myopulse) in tissue repairing on fatigue quadriceps femoris(rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis). Subjects were female adult volunteers with (n=13) and without (n=5) chronic fatigue muscle pain. We needed to fatigue the rectus femoris by overusing of a Cybex machine exercise. We turned the Electro-Myoscope to treatment mode and treated with treatment probe on the fatigue muscle, then turned instrument back to EMG and took the reading. The results indicated that the reading after the treatment was lower than before the treatment. A two-tailed t-test and Chi square indicated significant results(P<.03). It appears that the Electro-Myoscope is effective in treatment on the fatigue muscle.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.981-982
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• 2013

• Journal of The Korean Society of Integrative Medicine
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• v.2 no.3
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• pp.57-63
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• 2014

Purpose : The purpose of this study was to identify the muscle activity of leg during stair down in the subjects with flatfoot and normal foot. Methods : The fourteen subjects with the flatfoot group and the fifteen subjects with the normal foot group volunteered for this study. All subjects descended the stairs that the height was 20cm and consisted 25 stairs. The target muscles for recording muscle activity were posterior fiber of gluteus medius, vastus medialis and vastus lateralis oblique, semitendinosus and biceps femoris, tibialis anterior, and medial and lateral fiber of gastrocnemius muscles. The muscle activity was recorded using the wireless EMG system. Results : The flatfoot group had significantly lower the muscle activity of posterior fiber of gluteus medius than the normal foot group in stance phase during stair down(p<.05). The flatfoot group had significantly higher the muscle activity of biceps femoris and tibialis anterior than the normal foot group in swing phase during stair down(p<.05). Conclusions : This study proposed that the subject with flatfoot should train the strengthening exercise for posterior fiber of gluteus medius.