The purpose of this study was to investigate the correlation and characteristics between electromyographic (EMG) activities of lower leg muscles and the posturographic assessment of static balance control in normal adults. Twenty-four young, healthy adults(12 males, 12 females) participated in the study. Center of pressure (COP) parameters were obtained using force platform as total path distance, total sway area, X mean frequency and Y mean frequency for 20 seconds in the following conditions: (1) comfortable standing with eyes opened or closed, (2) uncomfortable standing (feet together) with eyes opened or closed, (3) virtual moving surround delivered using Head mount display (HMD) with four different moving patterns. The virtual moving patterns consisted of close-far, superior-inferior tilting (pitch), right-left tilting (roll), and horizontal rotation (yaw) movements. Surface electromyographic activites were recorded on the tibialis anterior, peroneus longus, medial and lateral heads of gastrocnemius muscles under each condition. Correlation between the posturographic measures and EMG activities were evaluated. Total path distance and total sway area of COP were significantly increased during uncomfortable standing. EMG activity of tibialis anterior was significantly more during uncomfortable standing and virtual moving surround stimulation than during comfortable standing. Total path distance and sway area of COP during comfortable standing with closed eyes showed significant positive correlation with the EMG activities of the lateral head of gastrocnemius muscle. Total path distances and total sway area of COP during muscle. Total path distances and total sway area of COP during presentation of virtual moving surround also had significant positive correlations with EMG activities of the lateral head of gastrocnemius muscle under close-far movement.

Altered scapular kinematics in the scapular joint is commonly believed to be a factor contributing to trunk posture. The purpose of this study was to analyze the muscle activity with several changes of the shoulder angle. Tests were performed on 10 male subjects by repeated measures. Each subject was measured while sitting in both erect and slouched trunk positions. In each sitting posture, a three-dimensional motion analysis measurement was used to measure thoracic angle and shoulder abduction angle. Measurements were taken with the shoulder abdcution angle at , , , , , and . By using surface Electromyography (EMG) electrodes, we recorded the activity of the upper trapezius, middle trapezius, lower trapezius, middle deltoid, and serratus anterior muscle while the subject held a 4 kg weight at each angle. The mean of root mean square (RMS) of EMG activity was calculated. The middle trapezius, lower trapezius, and middle deltoid muscle activity showed significantly higher results but serratus anterior muscle activity showed significantly lower results (p<.05). With the shoulder angle increased, the muscle activity was also significantly increased (p<.05). In conclusion, the thoracic spine posture significantly affects the scapular muscle during scapular plane abduction, and the slouched posture is associated with increased trapezius muscle activity and with decreased serratus anterior muscle activity.

본 연구의 목적은 운동강도(최대근수축의 10, 30, 50, 70%)에 따라 유발되는 국소적인 근피로가 슬관절의 위치감각 인지에 미치는 영향을 연구함으로써 근력강화의 운동치료적 효과와 운동학습과 관련된 효과를 동시에 만족시키는 최적의 운동강도를 제시하는 것이었다. 대상자는 건강한 성인여자 40명이었다. 청각을 통한 위치감각 정보를 제공하는 장치와 원판 각도계가 부착된 등속성 Cybex를 사용하였다. 근피로의 상태를 확인하기 위해서 근전도를 이용하여 주파

The purpose of this study was to analyze the effects of three different pelvic tilts on sit-to-stand ativities and to suggest a new therapeutic approach for movement reeducation in patients who have difficulty with sit-to-stand activities. The three different pelvic tilts were: (1) comfortable pelvic tilt sit-to-stand (CPT STS), (2) posterior pelvic tilt sit-to-stand (PPT STS) and (3) anterior pelvic tilt sit-to-stand (APT STS). To analyze the kinematic component of STS, a motion analysis system (Zebris) was applied to the ankle, knee, hip joint, and thigh-off area. Also, to determine the onset time of muscle contraction, surface electrodes were placed to the rectus femoris muscle (RF), the vastus lateralis muscle (VL), the biceps femoris muscle (BF), the tibialis anterior muscle (TA), the gastrocnemius muscle (GCM), and the soleus muscle (SOL). One-way repeated ANOVA was used for the statistical analysis. First, significant differences were found in kinematic variables for the hip, knee, ankle joint, and thigh-off among the three activities. Second, there was significant difference in muscle activation pattern in TA. VL. and BF among three activities. In conclusion, the findings of this study suggest the following evaluative and therapeutic approach for STS activity: (1) Changes in knee and ankle joints should be prioritized and recruitment order differences in VL and RF can be generated to accomplish abnormal STS activity. (2) APT STS can be introduced for movement efficiency and functional advantage when abnormal STS is treated.

The purpose of this study was to analyze the effects of three different pelvic tilts on a sit-to-stand (STS) and to suggest a new assessment approach based on biomechanical analysis. The three difrent pelvic tilts were: (1) comfortable pelvic tilt sit-to-stand (CPT STS), (2) posterior pelvic tilt sit-to-stand (PPT STS) and (3) anterior pelvic tilt sit-to-stand (APT STS). To determine the onset time of muscle contraction surface electrodes were applied to the rectus femoris muscle (RF), vastus lateralis muscle (VL), biceps femoris muscle (BF), tibialis anterior muscle (TA), gastrocnemius muscle (GCM), and soleus muscle (SOL). The ICC was used for functional linkage analysis. The findings of this study were as follows. First, significant differences were found in kinematic variables and in muscle activation pattern among the three activities. Second, the results of functional integrated analysis revealed that recruited muscle activation patterns changed when the thigh-off was viewed as a reference point. Third, there were independent functional units between the thigh-off and the VL and between the thigh-off and the RF in the functional linkage analysis. The VL and RF acted as prime mover muscles, and more postural adjustment muscle recruitment was required as the demand of postural muscle control increased (PPT STS, APT STS, and CPT STS in order). In conclusion, the findings of this study suggest the following evaluative and therapeutic approach for STS activity. APT STS can be introduced for movement efficiency and functional advantage when abnormal STS is treated. However, excessive APT would change the muscle activation patterns of BF and SOL and require additional postural muscle control to cause abnormal control patterns.

The purpose of this study was to investigate the effectiveness of the low-intensity ultrasound (noblelife) treatment on the pain points of upper trapezius muscle. The study recruited 20 patients who had trigger points in one side of the upper trapezius. The effectiveness of the low-intensity ultrasound treatment was assessed with subjective pain intensity using visual analog scale (VAS) and pressure pain threshold (PPT). The PPT was measured by pressure threshold algometer. Before and after the treatment, changes of pain were evaluated. Wilcoxon test for VAS data and paired t-test for PPT data were used for statistical significance. Compared to the pain intensity before the treatment, the pain intensity after treatment was significantly decreased (p<.05). Low-intensity ultrasound could be safely used in clinical application and at home for the treatment of patients with pain in upper trapezius muscle.

It was recently reported that exercise-induced fatigue is related to joint position sense although some controversy remains. The purposes of this study were to examine the effect on the accuracy of reproducing the knee angles after a fatiguing isokinetic quadriceps exercise at four different levels (10%, 30%, 50%, and 70% of maximal force) and to find the optimal exercise level without causing knee joint proprioception impairment. Forty healthy women, ages 19 to 27, were randomly assigned to four experimental groups. Before and after the exercise, accuracy of positioning with respect to auditory feedback for specific angles was estimated by calculating the mean errors between specific angles and reproduction angles. Fatigue was measured by EMG signals displayed by a frequency spectrum analysis during the quadriceps exercise. Results showed that there was no significant difference in accuracy of the knee joint positioning sense following the exercises in group 1, group 2, and group 3 (10%, 30%, and 50% of maximal force, respectively); the exception being group 4 (70%). Fatigue level was significantly increased in group 4 but there were no significant increases of fatigue level in group 1, group 2, or group 3. The results concluded that the optimal exercise level to acquire the therapeutic exercise effectiveness without position sense impairment was at 50% of maximal force. Further studies using large sample size and patient groups with poor knee joint proprioception would be needed to confirm this conclusion and to clarify the possibility of clinical applications.