ACUTE EFFECT OF VIBRATORY STIMULATION ON ELBOW JOINT FLEXOR PERFORMANCE

A novel design of vibratory stimulation training system was developed in this study. Each participant took a pre-test, before receiving treatment with 20 seconds of vibratory stimulation (VS) at a specific frequency and amplitude. The participants then took a post-test. Percentage improvement was then calculated by comparing the pre- and post-test values for each index. The experimental data were analyzed through a two-way repeated-measures ANOVA analysis, with the independent variables being vibratory frequency and amplitude and the dependent variables being EMG root mean square, maximal force, rate of force development, and average force. The optimal vibratory stimulation pattern was found from this study that being a 60% maximal force loading combined with VS at 2.5 Hz and 1 N amplitude sustained over 20 s

THE ANALYSIS OF PULLING FORCE CURVES IN TUG-OF-WAR

The purpose of this study is to analyze the pulling force curves in DFB and AFB movements that produced by elite tug-of-war athletes. The subjects are 11 female high school athletes who have been trained more than two years for tug-of-war. Data is analyzed by paired-sample t-test. The results show that force-related parameters are all different significantly between two movements, and time-related parameters are not significant. The DFB movement has higher value in MaxF, AveF, FS and lower value in MinF. We suggest to avoid the decay of pulling force while adopting DFB movement, and increase MaxF, AveF, and FS while adopting AFB movement. Within the start of 2sec we suggest the team to take the DFB movements in order to produce powerful pulling force, then transform to the AFB movements to keep the team formation

ACUTE EFFECT OF VIBRATORY STIMULATION ON ELBOW JOINT FLEXOR PERFORMANCE

A novel design of vibratory stimulation training system which can provide precisely controlled smooth force profile to the participants is introduced. All participants received 4 treatments with 20s of vibratory stimulation at a specific frequency and amplitude. The experimental data were analyzed through the two-way repeated-measures ANOVA analysis, with the independent variables being vibratory frequency and amplitude, and the dependent variables EMGrms, Fmax, RFD0.5s, and Fave. An optimal vibratory stimulation pattern was found from this study that has the most significant acute effect on the elbow joint flexor muscle performance: a 60% maximal force loading combined with vibratory stimulation at a frequency of 2.5 Hz and amplitude of 1 N sustained over 20s

THE NOVEL BIOMECHANICAL MEASUREMENT AND ANALYSIS SYSTEM FOR TUG-OF-WAR

Tug of war (TOW) is a kind of sport that has been accepted as one of the formal items in the Olympic game. Because of having well defined rule, the TOW has high potential to be extended to all over the world in the near future. To increase the possibility of success in the competition, athletes of the TOW should be subjected to a series of training courses. After experiencing certain training course, an athlete of TOW required to carry out pulling force test to evaluate his performance and consequently verify the effectiveness of the training course. In this study, a multi-purposes biomechanical measurement and analysis system is proposed in which various evaluations of the athlete performance. The idea of the proposed system is discussed and the associated theoretical methods are derived

THE ACUTE EFFECT OF UPPER EXTREMITY PLYOMETRIC TRAINING

The purpose of this study was to probe the acute effect of the performance of upper extremity muscle groups after the plyometric training intervention. The participants were 13 healthy male college students. The force transducers (300kg, 200 Hz) and EMG sensor (1000 Hz) were taken to diagnose the acute effects of strength and muscle activation done by upper extremity pre and post plyometric training (load :24kg, 12 repetiiion times Iset, 3 set), and pair t-test was taken to test the significance(a=.05). The result showed that the strength after the upper extremity plyometric training intervention obviously had decreased 8% (

ELEMENTARY SCHOOL BOYS’ SOCCER KICK SKILL ANALYSIS

The purpose of this study is aimed to analyze elementary school boys’ kicking skills on the perspective of motor skills. The data is collected by Vicon Motion Analysis System (250Hz). The parameters include the compare of the instant joint angles and the time proportion during the process of the kicking toward the different kick performance groups. The participants are 36 elementary boy soccer players (age: 11.7±0.3 yrs; height: 1.42±0.13 m; weight: 37.5±13.0 kg). The subjects were divided to two groups according to the instance kicking ball speed. The result indicated that the high ball speed group players have greater extremity joint angles than the low ball speed group. No difference was found on the time proportion during the process of the kicking. We suggest that the learning of kicking skill can start with the lower speed in the beginner stage

Recurrent chronic subdural hemorrhage due to cervical spinal CSF leak in a young adult: Report of a case

SummaryNontraumatic intracranial subdural hemorrhage may result from disorders at remote anatomic sites. Here, we report a young adult who suffered from bilateral subdural hematoma without antecedent head injury. The subdural hematoma did not resolve after surgical drainage. The symptom of postural headache prompted a contrast-enhanced magnetic resonance imaging (MRI) examination of the brain, which revealed signs indicative of intracranial hypotension. Subsequently, MRI of the spine demonstrated leakage of cerebrospinal fluid (CSF) in the upper cervical spine region. The patient recovered after conservative treatment. A review of the patient’s medical history revealed that the patient had chiropractic therapy on his neck 2 months prior to admission. Intracranial hypotension due to spinal CSF leak is a rare cause of subdural hemorrhage, yet it should be considered in the absence of head trauma

Changes in insulin sensitivity and lipid profile markers following initial and secondary bouts of multiple eccentric exercises

An acute bout of eccentric exercise affects insulin sensitivity and lipid profile, but how the magnitude of muscle damage affects them is not clear. We compared changes in blood insulin sensitivity and lipid markers after the first (EC1) and second (EC2) eccentric exercise bouts. Fifteen sedentary young men performed arm, leg and trunk muscle eccentric exercises, and repeated them 2 weeks later. Fasting blood samples were taken before, 2 h and 1–5 days after each exercise bout to analyze plasma creatine kinase (CK) activity, serum glucose (GLU), insulin, homeostasis model assessment (HOMA), triacylglycerols (TG), total (TC) and low- (LDLC) and high-density lipoprotein cholesterol (HDLC) concentrations as well as TC/HDLC ratio. Changes in these measures were compared between bouts and relationships to peak plasma CK activity were analyzed. Plasma CK activity increased (p \u3c 0.05) after EC1 (peak: 101,668 ± 58,955 IU/L) but not after EC2. The magnitude of changes in GLU (peak after EC1: 26 ± 10% vs. EC2: 7 ± 6%), insulin (46 ± 27% vs. 15 ± 8%), HOMA (86 ± 48% vs. 24 ± 15%), TC (−20 ± 5% vs. −6 ± 4%), TG (−32 ± 11% vs. −6 ± 3%), LDHC (−47 ± 15% vs. −12 ± 9%), HDLC (35 ± 26% vs. 7 ± 4%), and TC/HDLC ratio (−139 ± 13% vs. −11 ± 7%) were significantly greater after EC1 than EC2. Peak plasma CK activity was significantly (p \u3c 0.05) correlated with the peak changes in blood insulin sensitivity and lipid markers for the combined data of EC1 and EC2. These results suggest that the greater the magnitude of muscle damage, the greater the magnitude of changes in the insulin sensitivity to a negative direction and lipid markers to a positive direction

Contralateral versus ipsilateral protective effect against muscle damage of the elbow flexors and knee extensors induced by maximal eccentric exercise

The present study compared the ipsilateral repeated bout effect (IL-RBE) and contralateral repeated bout effect (CL-RBE) of the elbow flexors (EF) and knee flexors (KF) for the same interval between bouts to shed light on their mechanisms. Fifty-two healthy sedentary young (20–28 years) men were randomly assigned to the IL-EF, IL-KF, CL-EF, and CL-KF groups (n = 13/group). Thirty maximal eccentric contractions of the EF were performed in IL-EF and CL-EF, and 60 maximal eccentric contractions of the KF were performed in IL-KF and CL-KF, with a 2-week interval between bouts. Changes in muscle damage markers such as maximal voluntary contraction (MVC) torque, muscle soreness, and plasma creatine kinase activity, and proprioception measures before to 5 days post-exercise were compared between groups. Changes in all variables were greater (p \u3c 0.05) after the first than second bout for all groups, and the changes were greater (p \u3c 0.05) for the EF than KF. The changes in all variables after the second bout were greater (p \u3c 0.05) for the CL than IL condition for both EF and KF. The magnitude of the average protective effect was similar between CL-EF (33%) and CL-KF (32%), but slightly greater (p \u3c 0.05) for IL-EF (67%) than IL-KF (61%). These demonstrate that the magnitude of CL-RBE relative to IL-RBE was similar between the EF and KF (approximately 50%), regardless of the greater muscle damage for the EF than KF. It appears that the CL-RBE is more associated with neural adaptations at cerebrum, cerebellum, interhemispheric inhibition, and coricospinal tract, but the IL-RBE is induced by additional adaptations at muscles