Background: While the formal test has been used to provide a quantitative measurement of core stability, studies have reported inconsistent results regarding its test-retest and intraobserver reliabilities. Furthermore, the validity of the formal test has never been established. Objects: This study aimed to establish the concurrent validity and test-retest reliability of the formal test. Methods: Twenty-two young adults with and without core instability (23.1 ± 2.0 years) were recruited. Concurrent validity was determined by comparing the muscle thickness changes of the external oblique, internal oblique, and transverse abdominal muscle to changes in core stability pressure during the formal test using ultrasound (US) imaging and pressure biofeedback, respectively. For the test-retest reliability, muscle thickness and pressure changes were repeatedly measured approximately 24 hours apart. Electromyography (EMG) was used to monitor trunk muscle activity during the formal test. Results: The Pearson’s correlation analysis showed an excellent correlation between transverse abdominal thickness and pressure biofeedback unit (PBU) pressure as well as internal oblique thickness and PBU pressure, ranging from r = 0.856–0.980, p < 0.05. The test-retest reliability was good, intraclass correlation coefficient (ICC1,2) = 0.876 for the core stability pressure measure and ICC1,2 = 0.939 to 0.989 for the abdominal muscle thickness measure. Conclusion: Our results provide clinical evidence that the formal test is valid and reliable, when concurrently incorporated into EMG and US measurements.

Background: Bridging exercises are used to enhance the functional stability of the lumbopelvic region in clinical settings. Although most of the studies on bridging exercises have compared the complete activation of the trunk muscles, some recent studies have examined the functional stability of the trunk and the lumbopelvic region and assessed the appropriate recruitment of the local and global muscles during different task levels. Objects: The purpose of this study was to investigate the changes in muscle thickness in the transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles during a common bridging exercise on an unstable surface and to determine whether these changes differ based on the surface used. Methods: Twenty-five healthy young adults (8 males, 17 females) were recruited. The subjects were randomly assigned to either the exercise progression with a sling bridge group or the ball bridging exercise progression group, each with three stages of increasing difficulty. Each position was measured three times with an ultrasonic diagnostic imaging system, and the mean values were recorded for analysis. Results: No significant differences were observed between the TrA, IO, or EO muscle thickness ratios between the sling and ball exercise groups (p > 0.05). There were also no significant differences in the EO muscle thickness ratios between the tasks irrespective of whether the sling or ball was used. However, the TrA and IO thickness ratios in both groups were significantly greater during stages 2 and 3 compared to stage 1. Conclusion: The results suggest that the use of slings and balls during bridging exercises is effective in activating the deep abdominal muscles.

Background: The toe-spread-out (TSO) exercise has been introduced as a strengthening exercise for the abductor hallucis muscle in subjects with hallux valgus. Visual biofeedback using ultrasound imaging during exercise, may increase the ability to selectively contract the abductor hallucis muscle, compared with exercise alone. Objects: The aim of this study was to investigate the effects of ultrasound imaging visual feedback during the TSO exercise with respect to its influence on the angle of the first metatarsophalangeal joint (1st MPJ) and the cross-sectional area (CSA) of the abductor hallucis muscle in subjects with hallux valgus. Methods: Twenty-five healthy young subjects with a mean average age of 22.5 years, and a standard deviation of 2.3 years, were recruited for this study. Hallux valgus was defined as an angles greater than 15° angle of 1st MPJ. Goniometric measurement was used to determine the angle of 1st MPJ. In addition, an ultrasound system was used to collect the CSA of the abductor hallucis muscle in each foot. The angle of the 1st MPJ and CSA of the abductor hallucis were measured in three positions; the resting position, during TSO exercise, and during TSO exercise in conjunction with real-time ultrasound imaging feedback. All data analyzed using a repeated analysis of variance with Bonferroni correction in order to compare the dependent variables in all three positions. Statistical level of significance was set up as p<.05. Results: The angle of the 1st MPJ was noted to be significantly reduced and the CSA of the abductor hallucis to be significantly greater during TSO exercise used in conjunction with ultrasound imaging visual feedback, compared to when the values were recorded during TSO exercise alone (p<.05). Conclusion: Based on these findings, it can be concluded that the application of ultrasound imaging visual feedback during TSO exercise is more effective in contracting selectively the abductor hallucis than the use of exercise alone.

The lower trapezius muscle is an important stabilizer and primary mover of the scapula. The potential use of ultrasound imaging to evaluate scapular muscle function warrants investigation. The purpose of this study is to use ultrasound imaging for determining the effectiveness of 4 different isometric exercises for maximally activating the lower trapezius muscles in healthy subjects. Twenty-eight (14 men and 14 women) volunteers were recruited for this study. Thickness measurements of the lower trapezius muscles were recorded during 4 exercises: latissimus pulldown (LP), prone V-raise (PV), prone row (PR), and modified prone cobra (MP). Lower trapezius muscle thickness was measured 3 times by 2 investigators at a point 3 cm lateral to the lateral edge of the T8 spinous process. The order of 4 exercise execution was randomized for each participant. To identify statistical significance, one-way ANOVA with repeated measures was used with the significance level of .05. Intraclass correlation coefficient (ICC) for intra-reliability was .86~.98 and inter-rater reliability .83~.96 for the lower trapezius, respectively (p<.01). Thickness changes in the lower trapezius muscles between the relaxed and contracted states in men were as follows: LP (, 182%), MP (, 167%), PV (, 149%), and PR (, 133%). In women the values were as follows: LP (, 163%), MP (, 131%), PV (, 129%), and PR ( mm, 100%). Thickness of the lower trapezius muscles significantly differed between exercises in both the gender (p<.01). The LP was the most effective exercise for increasing the activation of the lower trapezius muscle in both the gender. We recommend performing the LP exercise for strengthening the lower trapezius muscles.

The purpose of this study was to investigate intra-rater reliability and determine the validity of electromyography (EMG) measurements to represent muscle activity and ultrasonography (US) to represent muscle thickness during manual muscle testing (MMT) to external abdominal oblique (EO) and lumbar multifidus (MF). Twenty healthy subjects were recruited for this study and asked to perform MMT at differing levels. The subjects' muscle activity using EMG was measured by a ratio to maximum voluntary contraction (MVC) and root mean square (RMS) methods. The subjects' muscle thickness using US was measured by raw muscle thickness and change ratio of thickness to maximum (MVC) or resting condition. In three trials, measurements were performed on each subject by one examiner. The intra-rater reliability of measurements of EMG and US to EO and MF was calculated using intra-class coefficients. The intra-rater reliability of all measurements was excellent (ICC=.75~.98) in EMG and US. The conduct validity was calculated by one-way ANOVA with repeated measurements to compare whether the EMG and US measurements were different between MMT at different levels. There was only a significant difference between all grades at %MVC thickness measurement of US. These results suggest that a %MVC thickness measurement of US was a more sensitive and discriminate in all manual muscle testing grades. This information will be useful for the selection of US measurement and analysis methods in clinics.

Acoustical imaging has made brilliant progress in the medical science field, and has also made much progress in the nondestructive testing and under water acoustics applications since doctor Dussik brother has studied about possibilities of making images of brain by recording variations in the intensity of ultrasonic beam from head in 1937. In this paper an acoustical image is reconstructed with the power spectra analysed by impulse ultrasound wave generated by electrodynamic transducer(EDT). The EDT generates the impulse ultrasound of 77KHz in center frequency and 120KHz in bandwidth at -20dB by 1200V exciter in this experiment. The impulse ultrasound has the dominant frequency components of 47KHz, 177KHz, 110KHz and 155KHz. The U shape object is adopted in making an acoustical image. The resulted spectral acoustical images are different from the optical view of the U shape object. However the image reconstructed from 110KHz spectrum is very similar to the original optical shape of the object. Even KHz level impulse sound of 70μsec pulse width is found to be useful in reconstructing acoustical imaging improvement.

수난 현장의 경우 부유물 등에 의하여 시계가 어두워 인명구조 및 인양에 어려움이 많다. 이에 시계뿐만 아니라, 시계를 대신해줄 수 있는 시스템이 필요로 한다. 최근 해상과 강에서의 사고가 빈번하게 일어나고 있으며, 이런 사고 구조 및 인양에는 잠수부들이 직접 들어가는 경우가 많다. 하지만 열악한 수중 환경으로 인하여 구조 및 인양에 어려움이 있고, 잠수부들의 2차 피해도 발생할 우려가 있다. 이러한 열악한 환경 중, 시계 환경의 열악함으로 잠수부들의 위치인식 불가, 구조물 확인 불가 등의 사유로 수난구조에 있어 중요한 정보들을 잃어버리는 경우가 많다. 현재 세계적으로 이러한 수중환경에서의 시계확보를 위한 초음파 카메라 등의 시스템이 제작 및 시판되고 있지만, 현재 개발 및 시판되는 시스템들은 시스템의 조작 및 이동에 두손이 사용되어져, 잠수부들이 구조 활동 중 구조물의 파악, 생존자의 구조 및 익사자의 인양 등에 사용 되어지는 두 손을 사용할 수 없는 단점이 있다. 이에 본 연구에서는 잠수부가 두 손을 자유롭게 사용할 수 있는 헬멧형 수난 구조탐색시스템을 개발하려고 한다. 헬멧형 수난구조 시스템을 개발함으로써 악조건의 수중환경에서도 시계 확보가 가능해지고, 잠수부들의 구조 활동 시 두 손의 사용이 자유로움으로 인해 구조 활동의 효율성이 오를 것으로 기대된다.