OBJECTIVES: Sensory gating dysfunctions in patients with schizophrenia and bipolar disorder have been investigated through two similar methods ; P50 suppression and prepulse inhibition paradigms. However, recent studies have demonstrated that the two measures are not correlated but rather constitute as distinct neural processes. Recent studies adopting spectral frequency analysis suggest that P50 suppression reflects the interaction between gamma and other frequency bands. The aim of the present study is to investigate which frequency component shows more significant interaction with gamma band. METHODS: A total of 108 mood disorder patients and 36 normal subjects were included in the study. The P50 responses to conditioning and test stimuli with an intra-pair interval of 500 msec were measured in the study population. According to P50 ratio (amplitude to the test stimulus/amplitude to the conditioning stimulus), the subjects with P50 ratio less than 0.2 were defined as suppressed group (SG) ; non-suppressed group (NSG) consisted of P50 ratio more than 0.8. Thirty-five and 25 subjects were included in SG and NSG, respectively. Point-to-point correlation coefficients (PPCCs) of both groups were calculated between two time-windows : the first window (S1) was defined as the time-window of one hundred millisecond after the conditioning auditory stimulus and the second window (S2) was defined as the time-window of 100 msec after the test auditory stimulus. Spectral frequency analysis was performed to investigate which frequency band results in the difference of PPCC between SG and NSG. RESULTS: Significant reduction of PPCC between S1 and S2 was observed in the SG (Pearson's r = 0.24), compared to PPCC of the NSG (r = 0.58, p < 0.05). In spectral frequency analysis, gamma band showed "phase-reset" and similar responses after the two auditory stimuli in suppressed and non-suppressed group. However in the case of alpha band, comparison showed significantly low PPCC in SG (r = -0.14) compared to NSG (r = 0.36, p < 0.05). This may be reflecting "phase-out" of alpha band against gamma band at approximately 50 msecs after the test stimulus in the SG. CONCLUSIONS: Our study suggests that normal P50 suppression is caused by phase-out of alpha band against gamma band after the second auditory stimulus. Thus it is demonstrated that normal sensory gating process is constituted with attenuated alpha power, superimposed on consistent gamma response. Implications of preserved gamma and decreased alpha band in sensory gating function are discussed.
Bipolar Disorder ; Humans ; Mood Disorders ; Schizophrenia ; Sensory Gating

We investigated the effect of scapular stabilization exercise on shoulder joints mobilization and pain release in youth baseball players. Total 15 youth baseball players were voluntarily participated, and randomly divided into one of two experimental groups: either stabilization exercise group (EXE, n=7) or control group (NonE, n=8). Stabilization exercises (i.e., punching, scapular retraction, scapular fold, shrug, pull over, seated press, scaption with retraction, body blade, rotator cuff) were administered to EXE (8 weeks, 3 times.wk(-1), 60-100 min.session(-1)). Muscular power using Biodex system 3, full range of motion (ROM) with a goniometer, and the degree of pain with the Visual Analogue Scale was assessed at both baseline and the time point of completion of 8 weeks training program. Twoway ANOVA (group vs. time) was adopted to observe any interactive effects between factors. The statistical significance level was set at alpha=.05. There was an improvement in muscular power at both slow (i.e., 60degrees/sec) and medium (i.e., 180degrees/sec) speed setting in isokinetic instrument during internal and external rotation on dominant shoulder, and internal rotation only (not with external rotation) on non-dominant shoulder. There was no change in ROM in NonE, but total ROM was significantly expanded in EXE, revealing only degree of internal rotation increased. VAS significantly decreased in EXE. In conclusion, scapular stabilization exercise exerted positive effect on muscular power output, full range of motion and pain release on shoulder joint in youth baseball players. This indicates that scapular stabilization exercise possibly exert meaningful effect in injury prevention and sport performance.
Adolescent* ; Baseball* ; Education ; Exercise ; Humans ; Range of Motion, Articular ; Shoulder Joint* ; Shoulder* ; Sports

PURPOSE: This study analyzed the muscle activity changes induced by motions of reaching forward and chest expansion that were examined from the bilateral muscles with rectus abdominis, external oblique, multifidus, and longissimus thoracic using Pilates cadillac instrument. METHODS: Nine young adult women, who have no musculoskeletal disorder and any of chronic diseases, were participated. Surface electromyography system was used for recording of all signals produced by muscles, and then normalized as percentage of maximum voluntary isometric contraction (%MVIC). The paired t-test and repeated measures of analysis of variance was performed. RESULTS: Reaching-forward motion showed a higher muscle activity from non-dominant external oblique muscle than that of the chest-expansion motion. During both reaching-forward motion and chest-expansion motion, MVIC values collected from dominant side of external oblique muscle were shown a significantly lower than the values obtained from non-dominant side (p < 0.05). Conversely, %MVIC values in external oblique muscle collected from dominant side showed a significantly higher than the values obtained from non-dominant side of the same oblique muscle (p < 0.05). Reaching-forward motion was caused a higher %MVIC on non-dominant external oblique muscle than that of the chest-expansion motion (p < 0.05). Regardless of dominant or non-dominant sides, external oblique muscle was shown the highest activation rate of all the other muscles during reaching forward action, and longissimus thoracic muscle was shown the highest activation rate of all the other muscles during chest expansion action. CONCLUSION: Reaching-forward motion is suitable for activating an external oblique muscle, and chest-expansion motion is an effective enough in activating of longissimus thoracic muscle.
Arm* ; Chronic Disease ; Electromyography ; Female ; Humans ; Isometric Contraction ; Muscles ; Paraspinal Muscles ; Rectus Abdominis ; Thorax ; Young Adult

Purpose: We investigated the effects of cold water immersion (CWI) treatment during half-time break on performance related physiological indices during second half soccer match. Methods: Twenty-two collegiate soccer players participated in the study. Subjects undertook 3 minutes head out seated with whole body immersion at 19 o C to 21 o C. Total four venous blood samples were collected and analyzed for markers of ionic regulations and inflammatory (interleukin [IL]-1b, IL-6, IL-8, IL-10, tumor necrosis factor-α , and vascular endothelial growth factor) and immune functions (immunoglobulin [Ig] G, IgG2, IgG2, IgG3, IgG4, IgA, and IgM). Results: Partial oxygen concentration and %SO 2 level was lowered in CWI. Hemoglobin and hematocrit values were not significantly different between experimental groups. While there was no notable effect was shown in Na ＋ and Ca 2＋ , K ＋ concentration was higher in CWI during second half match. There were no effects in any of inflammatory and/or anti-inflammatory cytokines and Ig. Conclusion These results suggest that CWI during half time break exert positively affects in buffering capacity and promote oxygen delivery to the actively recruited skeletal muscle, possibly results in improve soccer performance during second half match.

PURPOSE: The aim of this study was to investigate the changes of contraction patterns and the differences of activities in trunk muscles during dynamic balance (multidirectional tilting exercise). METHODS: Eight physically active male subjects participated in the study. Tilting exercises were included by four directions (i.e., forward, backward, left, and right side), and were undertaken at three different tilting degrees (i.e., 10°, 20°, and 30°). They performed two occasions of tilting exercise, separated by 6-week time interval. Surface electromyography system was used for record of any signals produced by muscles which normalized as percentage of maximum voluntary isometric contraction. RESULTS: There were no statistically significant different interactive effects in any of muscles between two factors (time vs. degree). However, we identified significant main effects of degrees (among 10°, 20°, and 30°) in muscle activations during maintaining with forward tilting (left and right longissimus, multifidus), backward tilting (left and right rectus abdominis, external oblique), left side tilting (right rectus abdominis, external oblique, longissimus, multifidus), right side tilting (left rectus abdominis, external oblique, longissimus, multifidus). CONCLUSION: Findings from this study allow the multidirectional tilting exercise to be considered as suitable for ameliorate muscle balance by inducing co-contraction in trunk muscles.
Electromyography ; Exercise ; Humans ; Isometric Contraction ; Male ; Muscles ; Rectus Abdominis