Effects of posture on velocity and accuracy during serve in tennis: Balance and postural asymmetry assessment

Method: Participants who were accepted for the research consisted of 16 volunteer male tennis players the mean age of was; 22.3 ± 3.4 years; age of sports 14.7 ± 3.7 years; height 178.8 ± 7.1 cm; body weight 76.6 ± 7.9 kg .; body mass index (BMI) 24.0 ± 2.6 kg; The average service velocity average of 146.9 ± 18.2 km / s is the highest; 156.8 ± 18.5 km / h. After anthropometric measurements, the test phase was initiated and they were asked to serve at 10 maximal velocity. The fastest and most accurate shot was recorded by using radar device during service shots. After that, functional movement screen test consisted of 7 movement was conducted. After then, (internal-external rotation flexion, hyper-extension, abduction for dominant shoulder, flexion and extension for wrist, supination and pronation for fore arm of normal range of motion was determined by using goniometer. Hand grip isometric strength test was conducted with hand dynamometer and best of two attempts was accepted as the highest value. Static E.C. and E.O. (eyes closed - eyes open) balance parameters was static Average C.o.P. X, Static Average C.o.P. Y, static ellipse area (mm2), static Perimeter (mm) E.C-E.O., static area ratio EC-EO static perimeter ratio and dynamic posturography balance parameter (Avarage Track error A.T.E %) was measured by isokinetic balance device. Global Postural System 400 device was used in posture analysis of participants and 12 body segments; anterior, head, shoulder, spine, hip. Lateral; neck, chest, shoulder, upper back, trunk, abdomen and lower back in the assessment of posture. Each segment was scored as 5-3-1 from 60 total score and assessed as perfect-fair-poor respectively. SPSS 18.0 statistics program was used in the analysis of data, and statistical significance level was accepted as p < 0.05. Result: In this study it was determined that internal rotation had no statistically significant effects on serve shot velocity (p = 0.31 > 0.05). However it was determined that external rotation of dominant arm had no effects on service shot velocity (p=0.66 >0.05). In addition, it was observed that posture had no effects on serve shot velocity (p=0.91 > 0.05). Besides that, it was observed through statistical results that it was no correlation between E.C.- E.O static perimeter ratio with the most succesful accuracy serve (p= 0.78 > 0.05). and also, due to correlation coefficient (r -0,624) negative correlation was observed that between E.C.-E.O. static are ratio between with the most succesful accuracy serve (p=0.01 ≤ 0.01). Besides, there was no correlation between height of tenis player with the most succesful accuracy serve (p= 0.24 > 0.05).