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

THE EVALUATION OF GROUND REACTION FORCES DURING TWO DIFFERENT SOCCER THROW-IN TECHNIQUES: A PRELIMINARY STUDY

The purpose of this study was to examine the differences in Ground Reaction Forces (GRF) between standing and running soccer throw-in. Six male amateur soccer players participated in the current study. All data are expressed as mean±SD. The longer distance was observed in the running throw-in than the standing throw-in. The standing throw-in showed higher values at Vertical (Fz) GRF during back swing, forward swing and release phases. However, that of the running throw-in during follow through phase was higher than that of the standing throw-in. As a result, the longer throwing distance in the running throw-in can be explained that the players spend shorter time in all phases at running throw-in than they did in the standing throw-in. This might causes efficient energy transfer from proximal to distal segment during the running throw-in

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

DEVELOPMENTAL DIFFERENCES OF KINEMATIC AND MUSCULAR ACTIVATION PATTERNS IN INSTEP SOCCER KICK

The aim of the study was to evaluate kinematic and muscular activation differences amongst different age groups of soccer players. Thirty male youth soccer players were divided into 3 groups according to their age (age 12-13; age 14-15; age 16-17). There were significant differences in ball velocities and isokinetic strength values amongst groups. Angular and linear velocities of hip, knee, ankle and toe were also significantly different (

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 (

The Effects of Whole Body Vibration Treatments on Lower Body Muscular Activity in Well-Trained Athletes from Different Sports Branches

A limited number of acute whole body vibration (WBV) studies have investigated the effects of WBV treatments which were applied with different vibration frequencies and amplitude combinations on lower extremity muscle activation of well-trained athletes from different sports branches. To compare the effects of WBV on lower extremity muscle activation via Surface Electromyography (sEMG) of well-trained athletes from different sports branches (soccer, basketball and swimming) during static and dynamic squat exercises. sEMG activities of Tibialis Anterior (TA), Gastrocnemius Medialis (GM), Vastus Medialis (VM), Rectus Femoris (RF), Vastus Lateralis (VL) and Biceps Femoris (BF) muscles of 7 male soccer players, 7 male basketball players, and 6 male swimmers were recorded during WBV applied in static squat and dynamic squat positions with different frequencies (30-35-40 Hz) and amplitude (2-4 mm) combinations separated from each other by 5 min passive rest periods. Each combination was applied for 30 sec. The highest muscle activation was determined in TA of the swimmers compared to soccer players during static squat with 4mm-30Hz WBV application (p=0.027). The lowest muscle activation was also determined in VL of the swimmers compared to soccer players during static squat with 2mm-40Hz WBV (p=0.049). During dynamic squat with 4mm-40Hz WBV, the highest muscle activity was determined in RF of the basketball players compared to swimmers (p=0.030). However, dynamic squat with 2mm-40Hz WBV application gave rise to the lowest muscle activation in VL of the basketball players compared to soccer players (p=0.042). Well-trained athletes from different sports branches demonstrated different neuromuscular responses to acute WBV treatments. WBV during dynamic squatting which was applied with 4mm-40 Hz may be more beneficial in enhancing neuromuscular performance acutely for well-trained male athletes since it resulted in higher levels of muscular activation responses according to the present study

Okçulukta işitsel uyarılmış beyin potansiyellerinin incelenmesi.

Archery can be described as a static sport requiring strength and endurance of the upper body, in particular the shoulder girdle (Mann, 1984; Mann & Littke, 1989). To get a good record in an archery competition, one requires well-balanced and highly reproducible movements during the shooting (Nishizono, 1987). The bowstring is released when audible impetus is received from a device called “clicker”. As the fall of the clicker is an acoustic stimulus, it may evoke a sequence of potentials that can be recorded from the scalp of an archer. Auditory Evoked Potentials (AEPs) occur at different latencies and with various relations to the auditory stimuli. Therefore, the present study aims at investigating the Long-latency Auditory Evoked Potentials in Recurve Archery. Research questions can be stated briefly as follows: (1) What kind of Brain Potentials are Evoked by the Event (Fall of Clicker) during Archery Shooting? (2) Is there any significant difference between the characteristics of the potentials measured in laboratory conditions and during archery shooting? (3) Is there any significant difference between the successful and unsuccessful shots in terms of Auditory Evoked Brain Potentials? (4) Does Archery Shooting session have any effect on Auditory Evoked Brain Potentials? The subjects of the present study were 10 non-archers (N=6 males; N=4 females) for control trials and 15 archers (N=9 males; N=6 females) for archery shooting experiments. All subjects reported normal hearing, had medical histories free of significant neurological problems, and were not taking medication known to affect brain activity. Six different control paradigms have been created. Archery shootings were performed from 18 m that is official competition distance with target face.AEBPs were recorded 200 ms before and 800 ms after the trigger (fall of the clicker) over the vertex during the shots of each subject. Paradigm 1 and 5 was conducted just before and after the archery shooting to test the effect of archery shooting on AEBPs. The hit-area is defined as the rectangle between (x1, y1), (x1, y2), (x2, y1), (x2, y2) and the miss-area is the outer part of the hit-area on the target face. The preliminary analysis has shown that fall of the clicker evokes long latency auditory brain potentials with the latency of 100 msec and 200 msec. These responses are called as N1-P2 components. The means and standard deviations of both N100 and P200 amplitudes were as follows: N100 = 27,73 ± 16,82, P200 = -21,89 ± 20,46. The latencies of given brain responses were also summarized as: N100 = 141,93 ± 41,46; P200 = 211,8 ± 43,97. N1 amplitude was significantly different in archery shooting than that of control conditions (p0.05). There was no significant difference between successful and unsuccessful shots in terms of N1-P2 components (p>0.05). An archery shooting session did not create any difference between these components recorded before and after the shot (p>0.05). Having higher N1 amplitudes during archery shooting can be explained by the known multi-component structure of this wave. Different lobes and regions of the brain can be active during the time of the scalp-recorded N1 and simultaneous involvement of several of these areas may be contributing to the electrical field recorded at scalp in the archery shooting paradigm.Ph.D. - Doctoral Progra