• Journal of the Korean Society of Physical Medicine
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• v.13 no.4
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• pp.9-17
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• 2018

PURPOSE: This study was conducted to compare the effects of the Graston-based massage method and microcurrent application on muscle fatigue after causing muscle fatigue of the quadriceps femoris by applying high-intensity exercise. METHODS: Study subjects (56 healthy subjects in their 20s) were randomized into a microcurrent group (MG), Graston group (GG), and control group (CG). To induce fatigue of the quadriceps femoris, the subjects performed squats 100 times without a break within about 5 minutes. Muscle fatigue was measured immediately after performing squats and 15 minutes after intervention. To measure muscle fatigue, surface electromyogram (EMG) was used to obtain and compare the median frequency. Microcurrent or Graston massage was applied to their quadriceps muscles 15 minutes after performing the squats. RESULTS: Muscle fatigue increased significantly in the vastus lateralis before and after intervention in the Graston group (p<.05), while no significant difference was observed in the rectus femoris and vastus medialis (p>.05). There were also no significant differences in the microcurrent group or the control group. CONCLUSION: Both the microcurrent group and Graston group showed a tendency for increasing median frequency values compared to the control group, but there was no significant difference except in the vastus lateralis treated with the Graston technique. Although there was no significant difference, the Graston technique could be utilized to reduce the occurrence of DOMS by preventing muscle fatigue in clinical practice or sports medicine.

• The Journal of Korea Robotics Society
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• v.19 no.2
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• pp.203-212
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• 2024

Simultaneous motion is essential in the activities of daily living (ADL). For motion intention recognition, surface electromyogram (sEMG) and corresponding motion label is necessary. However, this process is time-consuming and it may increase the burden of the user. Therefore, we propose a simultaneous motion recognition framework using data augmentation based on muscle activation model. The model consists of multiple point sources to be optimized while the number of point sources and their initial parameters are automatically determined. From the experimental results, it is shown that the framework has generated the data which are similar to the real one. This aspect is quantified with the following two metrics: structural similarity index measure (SSIM) and mean squared error (MSE). Furthermore, with k-nearest neighbor (k-NN) or support vector machine (SVM), the classification accuracy is also enhanced with the proposed framework. From these results, it can be concluded that the generalization property of the training data is enhanced and the classification accuracy is increased accordingly. We expect that this framework reduces the burden of the user from the excessive and time-consuming data acquisition.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.3
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• pp.99-111
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• 2023

PURPOSE: This study examined the effects of pelvic compression methods on the muscle activities of the trunk muscles during plank exercises in individuals with and without low back pain. METHODS: Individuals who experienced back pain for three or more days within the last six months (low back pain group, LBPG; n = 15) and those who did not (non-experienced low back pain group, NLBPG; n = 15) were instructed to perform plank exercise without pelvic compression or while wearing a ReaLine or Com-pressor belt. The electromyography (EMG) data was measured during each session of exercise. Surface EMG signals were collected for the rectus abdominis (RA), external oblique (EO), erector spinae (ES), and gluteus maximus (GM) muscles. The data were collected during three 5-s exercises with a 1-min rest period between the three sets. RESULTS: During the plank exercise, the muscle activity of the RA in the LBPG was significantly higher than that in the NLBPG (p < .05), and greater muscle activity was observed in the LBPG even when two pelvic compression methods were applied (p < .05). The muscle activity of RA was decreased significantly during pelvic compression according to the pelvic compression methods in both groups (p < .05). No significant interaction was observed between the groups or the pelvic compression methods for the RA, EO, ES, or GM muscle activities during plank exercises. CONCLUSION: Both pelvic compression methods reduced the RA muscle activity during plank exercises in individuals who had not experienced back pain within the last six months.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.1
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• pp.129-136
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• 2018

PURPOSE: This Study compared the level of activation of the muscles around the shoulder at the time of abduction through Pilates breathing and regular breathing by using quantified biofeedback. METHODS: Experiment was conducted on 25 healthy males and females in the age bracket of 20's~30's as the subjects. The level of activation of muscles displayed at the time of Pilates breathing were measured at intercostal (InC) muscle, transverse abdominis (TrA) muscle, internal oblique (IO) muscle and external oblique (EO) muscle by using surface electromyogram (EMG) and were provided as biofeedback. Moreover, the changes in the level of muscular activation at sternocleidomastoid (SCM) muscle, upper trapezius (UT) muscle and Deltoid (Del) muscle, which are the muscles around the shoulder, at the time of abduction of shoulder during Pilates breathing and regular breathing were measured. RESULTS: When abduction of shoulder is executed through Pilates breathing, the level of muscular activation of UT muscle was $11.56{\pm}7.10%$ at the time of exhaling of Pilates breathing and $17.54{\pm}9.57%$ at the time of exhaling of regular breathing. Del muscle also displayed lowered level of muscular activation at the time of Pilates breathing with $12.88{\pm}5.80%$ during inhaling and $15.14{\pm}5.49%$ during exhaling. CONCLUSION: In conclusion, the results could be interpreted as indicating that the muscle activities of upper trapezius and deltoid muscle were decreased based on Pilates breathing more than those on regular breathing.

• PNF and Movement
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• v.12 no.4
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• pp.209-215
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• 2014

Purpose: This study aims to understand the effect of balance training on ankle muscle activity and static balance in stroke patients. Methods: The subjects were composed of 12 patients who were admitted with chronic stroke in H, K, and R hospitals located in Gangwon-do from August to October 2014. This study conducted balance training on the subjects for 20 min a session, twice a day, five times a week for six weeks. This study measured the surface electromyogram (EMG) of the paretic side's tibialis anterior and medial gastrocnemius for muscle activity. Static balance was measured as a TETRAX stability index. The measurements were conducted before the experiment and six weeks after. The result was statistically analyzed using paired t-test at the significance level of 0.05. Result: Muscle activity of the paretic side's tibialis anterior and medial gastrocnemius did not show a significant difference in the comparison between pre- and post-balancing training. However, the stability index showed a significant difference (p<0.05) between standing with eyes open (NO) and standing on a sponge with eyes open (PO). Conclusion: Although balance training did not affect the muscle activity of chronic stroke patients, it had an effective influence on the stability index. That is, balance training was effective at the functional level, but it did not change the structure level in terms of the ICF evaluation standard. Balance training becomes more effective when it is applied in relation to task.