• Korean Journal of Applied Biomechanics
• /
• v.15 no.4
• /
• pp.67-74
• /
• 2005

The purpose of this study is to compare and analyze the muscle activations between the professional golfers without low back pain symptom and the professional golfers with low back pain symptom, and so identify the stress related to golf swings, and provide the basic data to minimize the low back pain and the injury risk. Using surface electrode electromyography, we evaluated muscle activity in 6 male professional golfers during the golf drive swing. Surface electrodes were used to record the level of muscle activity in the Abdominal Oblique, Elector Spinae, Rectus Abdominis, Gluteus Maximus muscles during the golfer's swing. These signals were compared with %RVC(Reference voluntary contraction) which was normalized by IEMG(Integrated EMG). The golf swing was divided into five phases: take away, forward swing, acceleration, early follow through, late follow through. we observed patterns of trunk muscle activity throughout five phases of the golf swing. The results can be summarized as follows: RES(Right Elector Spinae) had statistically significant difference in take away phase, LGM(Left Gluteus Maximus), LRA(Left Rectus Abdominis), LOA(Left Oblique Abdominal) had statistically significant difference in forward swing phase, RES(Right Elector Spinae), RGM(Right Gluteus Maximus), ROA(Right Oblique Abdominal) had statistically significant difference in acceleration phase, RES(Right Elector Spinae), RGM(Right Gluteus Maximus) had statistically significant difference in early follow-through phase, LES(Left Elector Spinae), RGM(Right Gluteus Maximus) had statistically significant difference in late follow through phase.

• Convergence Security Journal
• /
• v.15 no.5
• /
• pp.77-86
• /
• 2015

The organization shall minimize business risks associated with customer information leaks. Enhance information security activities through voluntary pre-check and must find a way to detect the personal information leakage caused by carelessness and neglect accident. Recently, many companies have introduced an information leakage prevention solution. However, there is a possibility of internal data leakage by the internal user who has permission to access the data. By this thread it is necessary to have the environment to analyze the habit and activity of the internal user. In this study, we use the SFI analytical technique that applies RFM model to evaluate the insider activity levels were carried out case studies is applied to the actual business.

• PNF and Movement
• /
• v.22 no.2
• /
• pp.315-324
• /
• 2024

Purpose: The aim of this study was to compare the activation of shoulder stabilizer muscles to variations of manual resistance during three-dimensional shoulder rehabilitation exercises. Methods: A total of 13 participants were included in this study. To normalize each muscle's activity, a maximal isometric voluntary contraction was performed by all participants. After receiving 30 minutes of training in three-dimensional shoulder rehabilitation exercises, participants randomly performed PNF arm and scapular patterns according to the intensities of manual resistance. The activities of the upper trapezius, lower trapezius, and serratus anterior were measured during these patterns. All exercises were performed for five seconds, and the average of three seconds, excluding the first and last seconds, was used for data analysis. Results: Lower trapezius activity was significant among manual resistance intensities. In both the PNF arm and scapular patterns, using 80% manual resistance of maximum resistance showed higher activity of the lower trapezius muscle compared to 20% of the maximum resistance. Conclusion: It is expected that PNF arm and scapular patterns, with varying intensities of manual resistance, can be used for early rehabilitation of patients with shoulder impingement syndrome.

• Physical Therapy Korea
• /
• v.17 no.1
• /
• pp.1-8
• /
• 2010

The purpose of this study was to compare EMG activity for pectoralis major muscle during shoulder movement with various abduction angle and rotation position in supine position. Fifteen healthy subjects were recruited for this study. All subjects performed shoulder horizontal adduction holding a 2 kg dumbbell in shoulder abduction $40^{\circ}C$, $70^{\circ}C$, $90^{\circ}C$, $130^{\circ}C$, $160^{\circ}C$ with shoulder neutral, internal rotation (IR), and external rotation (ER). Surface EMG activity was recorded from pectoralis major clavicle part and pectoralis major sternum part for 5 seconds and EMG activity was normalized to the value of maximal voluntary isometric contraction (%MVIC). Dependent variables were examined with 3 (Neutral, IR, ER) ${\times}$ 5 ($40^{\circ}C$, $70^{\circ}C$, $90^{\circ}C$, $130^{\circ}C$, $160^{\circ}C$) analysis of variance with repeated measures. The EMG activity of pectoralis major muscle was significantly different between shoulder abduction angles and between shoulder rotation positions (p<.05). The highest value of EMG activity of pectoralis major clavicle part among shoulder abduction angles was in $70^{\circ}C$ and, $90^{\circ}C$ in that order. The highest value of EMG activity of pectoralis major sternum part among shoulder abduction angles was in $130^{\circ}C$ and, $90^{\circ}C$ in that order. According to the rotation degree, shoulder ER showed the highest value and IR showed the lowest value in both muscle parts. These results suggest that shoulder abduction $70^{\circ}C$, $90^{\circ}C$, $130^{\circ}C$ will be effective during manual muscle testing (MMT) and strengthening exercise for pectoralis major muscle. It is also supposed that shoulder ER is the efficient posture for strengthening of pectoralis major muscle.

• PNF and Movement
• /
• v.15 no.2
• /
• pp.167-176
• /
• 2017

Purpose: This study investigated the effect of core and abdominal muscle-strengthening exercises on muscle activity in the lower extremity on unexpected perturbation. Methods: Twenty subjects were randomly divided into the core exercise group (n=10) or the abdominal muscles strengthening group (n=10). The two groups performed their exercises during three sessions a week for a total of four weeks. The muscle activity in the lower muscles (rectus femoris, biceps femoris, tibialis anterior, gastrocnemius) was assessed using surface electromyography (EMG) and normalized maximal voluntary isometric contraction (MVIC) before and after the exercises. Results: An increase in the tibialis anterior activity after the core and abdominal muscles strengthening exercises was found after four weeks. A significant difference in the pre- and post-exercise was found. The gastrocnemius muscle activity increased in the core exercise group more than the abdominal muscles strengthening group. However, the difference was not significant. Conclusion: The results of this study suggest that the core and abdominal muscles strengthening exercises increased the tibialis anterior muscle activity. It is expected to help make more balance ability that affect who has abdominal muscles weakness.

• The Journal of Korean Physical Therapy
• /
• v.28 no.1
• /
• pp.46-51
• /
• 2016

Purpose: This study intended to classify voluntary respiratory exercise and exercise using breathing training equipment to suggest proper respiratory exercise to relieve symptoms of patients with severe chronic obstructive pulmonary disease. Methods: Sixteen subjects were randomly selected for experimental group I, which performed feedback breathing exercise and 15 subjects were randomly selected for experimental group II, which performed a complex breathing exercise. The mediation program was performed 30 minutes a session, once a day, three times a week, for five weeks. This study analyzed before and after results within groups and between groups through measurement of respiratory muscle activity and health-related quality of life. Results: Activity of sternocleidomastoid muscle and scalene muscle increased meaningfully within experimental group I and activity of diaphragm increased significantly within experimental group II (p<0.05) and there was a meaningful difference in health-related quality of life within experimental group II (p<0.05). Significant differences in change of activity of respiratory muscle and health-related quality of life were observed between groups (p<0.05). Conclusion: This study showed conflicting results between activity of agonist and synergist in patients with severe chronic obstructive pulmonary disease according to types of respiratory exercise and that complex respiratory exercise is more effective in health-related quality of life. Therefore, it found that the more severity increase, the more self-respiratory technique is an effective program. Diversified approach methods will be needed to improve respiratory function and quality of life for patients, and continuous clinical studies will be needed in the future.

• Journal of the Korean Society of Physical Medicine
• /
• v.4 no.4
• /
• pp.221-229
• /
• 2009

Purpose : The purpose of this study was to assess the effect of bridging stabilization exercises of trunk muscles activity on a Swiss ball according to change of position. Methods：30 healthy university students volunteered to participate in this study. Subjects were required to complete following three exercise positions. Exercise position 1; Supine bridge with Swiss ball, Exercise position 2; Side bridge with Swiss ball, Exercise position 3; Prone bridge with Swiss ball. Surface electromyography from selected trunk muscles was normalized to maximum voluntary isometric contraction. Results : A repeated measures of ANOVA with Duncan's correction was used to determine the influence of exercise type on muscle activity for rectus abdominis, external oblique, erector spinae. The erector spinae of exercise position 1 showed significantly higher muscle activity than exercise position 2, 3(p<.05). The external oblique of exercise position 2, 3 showed significantly higher muscle activity than exercise position 1(p<.05). The rectus abdominis of exercise position 3 showed significantly higher muscle activity than exercise position 1, 2(p<.05) Conclusion： These results indicate that muscle activity can be influenced by addition of a Swiss ball in bridging exercises. It is recommend to use a Swiss ball for trunk stabilization exercise.

• Journal of International Academy of Physical Therapy Research
• /
• v.11 no.4
• /
• pp.2253-2260
• /
• 2020

Background: Patients with low back pain (LBP) experience misalignments in the center of pressure (COP) and muscle imbalances due to frequent onesided posture adjustments to avoid pain. Objectives: To identify the effects of Squat Exercises with Vertical Whole-Body Vibration on the Center of Pressure and Trunk Muscle Activity. Design: Randomized controlled trial. Methods: Thirty LBP patients with an imbalance in the COP were sampled and randomly assigned to an experimental group of 15 patients who under went an intervention involving squat exercises with vertical WBV and a control group of 15 patients who were treated via a walking intervention. As pretests before the interventions, the subjects' COP was identified by measuring their stability index (ST), and erector spinae, rectus abdominis, transverse abdominis, gluteus medius muscle activity was analyzed by determining the % reference voluntary contraction (%RVC) value using surface electromyography while sit to stand. After four weeks, a post test was conducted to remeasure the same variables using the same methods. Results: Statistically significant differences were found in the ST (P<.01) and trunk muscle (P<.05, P<.001) in the experimental group before and after the intervention. In terms of the differences between the left- and right-side (RL) muscle activity, only the transverse abdominis (TrA) and gluteus medius (GM) exhibited statistically significant increase (P<.05). A comparison of the groups showed statistically significant differences in the TrA with respect to muscle activity (P<.05) and in the RLTrA and RLGM in terms ofthe difference between left- and right-side muscle activity (P<.01). Conclusion: Squat exercises with vertical WBV produced effective changes in the COP of patients with LBP by reducing muscle imbalances through the delivery of a uniform force. In particular, strengthening the TrA and reducing an imbalance in the GM were determined to be important factors in improving the COP.

• Physical Therapy Rehabilitation Science
• /
• v.10 no.2
• /
• pp.205-211
• /
• 2021

Objective: This study aimed to identify the effects of assuming different knee angles and hip abduction during bridge exercise and hip thrust exercise on lower body muscle activity. Design: Cross-sectional study Methods: Thirty-three healthy adults (18 men and 15 women) were instructed to perform the bridge and hip thrust exercises while randomly assuming 120°, 90° and 60° of knee flexion and 0° and 30° of hip abduction. EMG data (%maximum voluntary isometric contraction) were recorded three times from the erector spinae (ES), gluteus maximus (GM) and biceps femoris (BF) muscles of participant's dominant side and the mean values were analyzed. Results: The results showed that, during the hip thrust compared to the bridge exercise, there was significantly greater gluteus maximus muscle activity in all hip conditions while the biceps femoris activity was significantly less, and the erector spinae muscle activity was significantly greater with 30° of hip abduction (p<0.05). With all exercises, the erector spinae and the biceps femoris exhibited significantly greater muscle activity with 60° of knee flexion compared to 90° and 120° of knee flexion (p<0.05), and significantly greater muscle activity with 90° compared to 120° of knee flexion (p<0.05). In the case of the gluteus maximus, greater muscle activity was exhibited with 120° compared to 60° of knee flexion with all hip abduction conditions (p<0.05). Conclusions: It was effective for muscle activation of main agonists such as the gluteus maximus and erector spinae during thrust exercise, and the change in knee flexion angle was effective for muscle activation of the gluteus maximus. Therefore, it is considered that this study can be used as a selective indicator of the target movement angle during hip strengthening exercise for specific muscles.

• PNF and Movement
• /
• v.16 no.2
• /
• pp.295-300
• /
• 2018

Purpose: This study aimed to determine whether the abdominal muscles, which are the major lumbar stabilizers along with the respiratory muscles, are affected by smoking. We compared abdominal muscle activity between smokers and non-smokers during the sit-to-stand movement. Methods: A total of 28 healthy adult males (14 smokers and 14 non-smokers) in their 20s-30s voluntarily participated in the study. The subjects performed the sit-to-stand movement, and then their abdominal muscle activity was measured. The surface electromyography system was employed to measure the maximal voluntary isometric contraction (MVIC) values of the subjects' rectus abdominis, external oblique abdominal, internal oblique abdominal, and transversus abdominis muscles. Then, the values were quantified into %MVIC. Results: The activity of the rectus abdominis muscle was higher in the smokers than in the non-smokers. Conversely, the activity of the internal oblique abdominal and transversus abdominis muscles, which are deep abdominal muscles, was higher in non-smokers than in smokers, but the difference was not statistically significant. Conclusion: Smoking can inhibit the activity of smokers' deep abdominal muscles and increase the activity of their superficial muscles, thus making it detrimental to their musculoskeletal system.