The investigation of effects of whole body vibration on some tennis performance parameters

It is known that Whole Body Vibration (WBV) can increase intramuscular and intermuscular coordination and consequently, can improve motoric features such as strength, speed and flexibility by making an impact on muscle spindles and golgi tendon organs. In this research, the aim is to examine the effect of WBV on some performance parameters of tennis like International Tennis Number (ITN) scores, serve speed, reactive agility (with or without racket), 5m, 10m, 20m sprint speed and the relationship between isokinetic strength and serve speed. 19 tennis players participated in the research as volunteers: Nine of these volunteers comprised the training group (age: 21,55±2,69 year, training age: 32,44±13,42 month, height: 171,44±8,06 cm, weight: 63,66±12,62 kg) and 10 of them were the control group (age: 21,40±2,59 year, training age: 37,30±21,74 month, height: 172,10±9,82 cm weight: 64,90±11,22 kg). Some arrangements were made to remove the human factor in ITN test and serve speeds were measured with radar devices within the ITN test. Reactive agility and sprint tests were measured by electronic timing system. Isokinetic strength values (consentric/consentric) were measured for three joints in total for internal/external rotations with 90 degrees shoulder abduction position, knee flexion/extension and hip flexion/extension. Only dominant legs and arms of athletes were tested in 600.s-1 angular speed with three maximal repeats. After the measurement procedure, training group practiced increasing incrementally performance levels for eight weeks from 1 to 4, three times a week and one level for every fortnight. Since the data shows a normal distribution, Independent Samples T-Test were used for the comparison of training and control groups. One-samples T-Test were used for each group to analyze and see if there are differences between pretest-posttest values of designated independent variables. Pearson Correlation Analysis were used to examine the relationship between isokinetic strength and serve speed values. Statistical significance was taken as p<0.05 in all test. It was identified that vibration training group showed signs of improvement in every defined parameter with varied percentages. The correlation between isokinetic strength and serve speed was seen as low and training group showed a higher percentage of increase compared to control group in statistical sense (p<0.05). Finally, it has been revealed that WBV training made the athletes improve in defined parameters. On the other hand, detailed studies with collective use of video analysis, electromyography and force plate systems involving different angular speeds are needed to better understand the relationship between isokinetic strength and serve speed.