THE EFFECTS OF WHOLE-BODY VIBRATION ON EMG OF LEG MUSCLES WHICH ARE DIFFERENT FATIGUE RESISTANT DURING STATIC CONTRACTIONS

The purpose of the present study is to determine the effects of static whole body vibration (WBV) stimuli at low (2 mm) and high (4 mm) amplitudes and various frequencies (30-35- 40 Hz) on the neuromuscular responses of leg muscles which are different fatigue resistant. The fatigue protocol used for the determination of the fatigue index (FI).The study population was divided into two groups according to the values obtained by the FI (Group I: Less Fatigue Resistant (LFR), n=11; Group II: More Fatigue Resistance (MRF), n=11). Study results showed that LFR group that experienced a significantly higher percentage increase in the EMG activation values during higher frequencies (40 Hz) and amplitudes (4mm) (

THE DIFFERENT RELEASE TECHNIQUES IN HIGH LEVEL ARCHERY: A COMPARATIVE CASE STUDY

Olympic archers use different hook techniques like upper and lower two-finger hook. So, the purpose of this study is to compare three different hook techniques in archery by using kinetic and kinematic methods. A high level archer (FITA scores > 1300) volunteered to participate in this study. The subject engaged in a single test session consisting of 6 shots. Nine forearm and shoulder girdle muscles activation were quantified. The finger hook affected isometric contraction before the snap of the clicker causing sudden contraction of extensors and gradual relaxation of flexor muscles. This finding support earlier finding in the literature. Results showed that three finger hook strategy can be used in the drawing arm with success, as it may avoid causing a lateral deflection of the bowstring

SHORT-TERM EFFECTS OF 3 DAYS INTENSIVE WHOLE BODY VIBRATION EXPOSURE ON MUSCULAR ACTIVATION STRATEGIES

The aim of this study was to investigate 3-days intensive whole body vibration (WBV) exposure on activation strategies of lower extremity muscles. For this purpose, six male athletes’ dominant leg muscles (Tibialis Anterior(TA), Gastrocnemious Medialis(GM), Vastus Medialis(VM), Rectus Femoris(RF), Vastus Lateralis(VL) and Biceps Femoris(BF)) were recruited voluntarily. Before the trails their baseline electromyography (EMG) values were taken for reference evaluation. After that, they were trained static semi-squat position with 120o knee flexion angle on vibration platform (vertical vibration; 4 mm(high), 30 Hz), during 3 days. The subjects were exposed to vibration 6 times for duration of 60 seconds with a 2 minutes rest between each treatment. Consequently, 3 days intensive WBV exposure caused a progressive increase in EMG activity (

ELECTROMYOGRAPHY ACTIVITIES OF UPPER AND LOWER EXTREMITIES IN TABLE TENNIS DURING FOREHAND TOPSPIN AND NO SPIN STROKE: A CASE STUDY

The purpose of this study was to compare upper and lower extremity muscles activations between the forehand topspin and no spin strokes. A right-handed male elite table tennis player performed 13 forehand topspin strokes and 13 forehand no spin strokes against a ball machine. Electromyography (EMG) activities from his 10 upper and lower extremity muscles were recorded during these strokes and analyzed using a wireless EMG device. According to descriptive statistics, there seemed to be high-level differences in muscular activities between forehand no spin and forehand topspin strokes

EFFECTS OF 8-WEEKS WHOLE BODY VIBRATION TRAINING ON SOME MARKERS 06 TENNIS PERFORMANCE

The aim of the current study was to investigate the effects of Whole Body Vibration (WBV) training on some tennis performance parameters like International Tennis Numbr (ITN) scores, serve speed, reactive agility (with and without racket), 5171, 10m, 20m sprint and isokinetic strength values. 19 tennis players (training group: 9, control group: 10) participated in the research as volunteers. All the selectd parameters were measured before and after the training protocol. While control group was following regular tennis training, intervention group practiced WBV training for eight weeks (3 times a week, 1 level up for every fortnight, 15-20 mins per section). Consequently, it has been revealed that WBV training made an increase in selected performance parameters of athletes

KINETIC AND KINEMATIC ANALYSIS OF RECURVE ARCHERY SHOOTING TECHNIQUE

The study investigated shooting techniques of the archers with kinetic and kinematic methods. Twenty-seven archers of different skill levels have been involved into the current study to investigate both muscular activation strategies of nine muscles and some kinematic data on drawing hand side. A statistical significant difference (p0.05) in the time-dependent exchange values of the angle of the joints, a difference was detected in the graphical sense. Elite archers use distal muscles less but proximal and axial muscles more, and mid-level and novice archers use distal muscles more to pull the bowstring. This was interpreted to be the most important factor affecting the horizontal oscillation (lateral diflection) of bowstring

THE EFFECTS OF WHOLE BODY VIBRATION ON POSTURAL CONTROL: THE FREQUENCY OF STIMULATION

This study investigated the efficacy of high and low-frequency acute whole-body vibration (WBV) on postural control ability. WBV stimulus were applied the following determinants: (1) type (vertical) (2) frequency (30 and 40 Hz), (3) stance position (static squat position), (4) amplitude (4mm mm), (5) knee flexion angle (120°) and time (60s).Motion of the point of application of the vertical component [medio-lateral (ML) and anterio-posterior (AP)] of the ground reaction force (center of pressure, COP). The study results showed that static WBV stimuli given at low and high frequencies and 4 mm amplitude resulted in a different postural adaptation (

Optimizing of Wear Performance on Elevated Temperature of ZrO2 Reinforced AMCs Using Weighted Superposition Attraction Algorithm

462-474In the current study, the zirconium oxide (ZrO2) reinforced Aluminium Matrix Composites (AMCs) was designed as a brake lining and produced by mechanical alloying (MA) method. Wear tests of AMCs were performed according to ASTM G-99 at different sliding distance, operating temperatures and load in the range of 53 to 94 m, 20 to 340℃ and 10 to 30 Nrespectively. Optimum wear performance parameters were determined using the Weighted Superposition Attraction (WSA)algorithm. Firstly, to formulize the problem as an optimization problem through the guidance of the regression modelling, anexperimental design has been constructed, and the wear tests have been done at different reinforced rates, operatingtemperature and loads. Secondly, WSA algorithm has been adapted to tackle the formulated optimization problem.According to the results of WSA algorithm, the optimum rate of zirkonium oxide (ZrO2), load and operating temperaturewas determined as 12%, 206.33°C and 21.20 N respectively while keeping the friction coefficient between 0.15–0.24

Atrial electromechanical delay is impaired in patients with primary hyperparathyroidism

Introduction: Primary hyperparathyroidism (PHPT) is an endocrine disease that poses a risk for cardiac arrhythmias. Atrial electromechanical delay (EMD) has been known as an early marker of atrial fibrillation (AF). This study aimed to evaluate the atrial EMD in PHPT. Material and methods: Fifty PHPT patients (45 females, 5 males) aged 30–75 years and 38 controls (35 females, 3 males) aged 31–73 years were included in the study. Atrial EMD parameters were measured by using tissue Doppler imaging (TDI). Inter-atrial EMD was calculated as the difference between PA lateral and PA tricuspid; intra-atrial EMD was calculated as the difference between PA septum and PA tricuspid, and left-atrial EMD was calculated as the difference between PA lateral and PA septum. Results: Atrial EMD parameters (PA lateral, PA septum, PA tricuspid) significantly increased in the PHPT group compared to the control group (p < 0.001, for all). Also, inter-atrial and intra-atrial EMD were higher in the PHPT group than in the control group (p < 0.001, for all). In correlation analysis, calcium was closely associated with PA lateral (r = 0.749, p < 0.001), PA septum (r = 0.735, p < 0.001), inter-atrial EMD (r = 0.807, p < 0.001), and intra-atrial EMD (r = 0.838, p < 0.001). The same correlation relationship was seen between PTH levels with PA lateral (r = 671, p < 0.001), PA septum (r = 0.660, p < 0,001), inter-atrial EMD (r = 0.674, p < 0.001), and intra-atrial EMD (r = 0.732, p < 0.001). Conclusions: Atrial EMD parameters were prolonged in PHPT. The measurement of atrial EMD parameters might be used in determining the risk of AF development in PHPT