Validity and Reliability of the Newly Developed Surface Electromyography Device for Measuring Muscle Activity during Voluntary Isometric Contraction.

OBJECTIVE: The purpose of this study was to establish the validity and reliability of the newly developed surface electromyography (sEMG) device (PSL-EMG-Tr1) compared with a conventional sEMG device (BTS-FREEEMG1000). METHODS: In total, 20 healthy participants (10 males, age 30.3 ± 2.9 years; 10 females, age 22.3 ± 2.7 years) were recruited. EMG signals were recorded simultaneously on two devices during three different isometric contractions (maximal voluntary isometric contraction (MVIC, 40% MVIC, 80% MVIC)). Two trials were performed, and the same session was repeated after 1 week. EMG amplitude recorded from the dominant biceps brachii (BB) and rectus femoris (RF) muscles was analyzed for reliability using intrasession intraclass correlation coefficient (ICC). Concurrent validity of the two devices was determined using Pearson's correlation coefficient. RESULTS: Nonnormalized sEMG data showed moderate to very high reliability for all three contraction levels (ICC = 0.832-0.937 (BB); ICC = 0.814-0.957 (RF)). Normalized sEMG values showed no to high reliability (ICC = 0.030-0.831 (BB); ICC = 0.547-0.828 (RF)). sEMG signals recorded by the PSL-EMG-Tr1 showed good to excellent validity compared with the BTS-FREEEMG1000, at 40% MVIC (r = 0.943 (BB), r = 0.940 (RF)) and 80% MVIC (r = 0.983 (BB); r = 0.763 (RF)). CONCLUSIONS: The PSL-EMG-Tr1 was performed with acceptable validity. Furthermore, the high accessibility and portability of the device are useful in adjusting the type and intensity of exercise.

Effect of physical therapy scoliosis specific exercises using breathing pattern on adolescent idiopathic scoliosis.

[Purpose] This study was performed to confirm physical therapy scoliosis specific exercises on adolescent idiopathic scoliosis patients. [Subject and Methods] A 15-year-old male middle school student with scoliosis. Cobb's angle, angle of rotation of the spine, and breathing pattern were measured before and after 8 weeks training. [Results] After 8 weeks training, Cobb's angle, angle of rotation of the spine, and breathing pattern were improved better. [Conclusion] These results indicate that physical therapy scoliosis specific exercises improves scoliosis curves and could provide an effective intervention and management of scoliosis.

Abdominal muscle activity according to knee joint angle during sit-to-stand.

[Purpose] This study assessed the activity of the abdominal muscles according to the angle of the knee joints during sit-to-stand. [Subjects and Methods] Thirty healthy adult males participated in this study. Subjects initiated sit-to-stand at knee joint angles of 60°, 90°, or 120°. An electromyography system was used to measure the maximum voluntary isometric contraction of the rectus abdominis, external oblique, and internal oblique and transverse abdominis muscles. [Results] Percent contraction differed significantly among the three knee joint angles, most notably for the internal oblique and transverse abdominis muscles. [Conclusion] Wider knee joint angles more effectively activate the abdominal muscles, especially those in the deep abdomen, than do narrower angles.

Differences in abdominal muscle activation during coughing between smokers and nonsmokers.

[Purpose] The purpose of this study was to compare the activity of the abdominal muscles during coughing between smokers and nonsmokers. [Subjects] A total of 30 healthy adults (15 smokers, 15 nonsmokers) participated. [Methods] The percentage maximal voluntary isometric contraction values (%MVIC) of the rectus abdominis (RA), external abdominal oblique (EO), and internal abdominal oblique (IO) and transversus abdominis (TrA) were measured using surface electromyography. [Results] The %MVIC of the IO and TrA statistically significantly differed and the %MVIC of IO and TrA was found to be higher during coughing in nonsmokers compared with during coughing in smokers. [Conclusion] The activity of the deep abdominal muscles in nonsmokers was also higher than that of smokers during coughing.

Differences in the activation of abdominal muscles during trunk extension between smokers and non-smokers.

BACKGROUND: Many studies reported that the morbidity of the respiratory and circulatory diseases is higher among smokers than non-smokers. Some recent studies reported the effects of smoking on the musculoskeletal system. However, it is difficult to generalize the experimental environment because it is different from activities of daily living environment. OBJECTIVE: The purpose of this study was to compare the differences in the activation of abdominal muscles during trunk extension between smokers and non-smokers. METHODS: The subjects were 30 healthy adults (15 smokers and 15 non-smokers). The percentage of maximal voluntary isometric contraction (%MVIC) values of rectus abdominis (RA), external oblique (EO), internal oblique and transversus abdominis(IO&TrA) were measured using the surface electromyography System. RESULTS: The results showed no significant differences in the %MVIC of RA and EO between smokers and non-smokers. However, the %MVIC of IO&TrA showed a significant difference between smokers and non-smokers. The %MVIC of IO&TrA of non-smokers was higher. CONCLUSIONS: The non-smokers showed greater activation of deep abdominal muscles than smokers did.

Muscle tone changes in the lower limbs of stroke patients induced by trunk stabilization exercises.

bstract. [Purpose] The purpose of this study was to identify the effects of trunk stabilization exercises on the spasticity of the lower limbs in stroke patients. [Subject] The subject of this study was a 38-year-old male patient who experienced a spontaneous intracranial hemorrhage, and had motor paralysis symptoms and spasticity on the left side. [Methods] The Hmax/Mmax ratio was measured before and after the trunk stabilization exercises, by using proprioceptive neuromuscular facilitation techniques. [Results] The Hmax/Mmax ratio changed from 37% to 20%. [Conclusion] Trunk stabilization exercises help control the muscle tone in stroke patients.

The changes of pulmonary function and pulmonary strength according to time of day: a preliminary study.

[Purpose] The purpose of this study was to identify changes in pulmonary function and pulmonary strength according to time of day. [Subjects and Methods] The subjects were 20 healthy adults who had no cardiopulmonary-related diseases. Pulmonary function and pulmonary strength tests were performed on the same subjects at 9:00 am, 1:00 pm, and 5:00 pm. The pulmonary function tests included forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and forced expiratory flow between 25 and 75% of vital capacity (FEF25-75%). Pulmonary strength tests assessed maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP). [Results] FEV1 showed statistically significant differences according to time of day. Other pulmonary function and pulmonary strength tests revealed no statistical differences in diurnal variations. [Conclusion] Our findings indicate that pulmonary function and pulmonary strength tests should be assessed considering the time of day and the morning dip phenomenon.