علاقة بعض المتغيرات البيوميكانيكية و عضلات الذراع الضاربة بسرعة إنطلاق الكرة في أداء بعض مهارات التنس للاعبي الكراسي المتحركة

Abstract EN

Search aim: Identify The relation of some biomechanical variables and the muscles of the arm striking on the speed of the ball in the performance of some skills for tennis wheelchair.

Curriculum used: The researcher used the Descriptive method; due to its appropriateness to the nature of the research.

- Research Sample and Characteristics: (5) High level players in tennis on wheelchairs category (paralysis) from Al-sayd sporting Club Alexandria, in sport season 2018/2019.

- They have the following characteristics:- - Players’ convergence in the training and the chronological age.

- Registered in the Egyptian tennis Federation.

- Players’ convergence in the degree of motor disability (paralysis) - Not participating in any other research programs and agreeing to make measurements.

The most important results: - The most important muscles effecting the velocity of the ball for both the skill of serve and the for hand and back hand strike (Biceps brachia muscle - Triceps brachia muscle - the interior and posterior Deltoid muscle - the Pectoralis major muscle - the Teres major muscle - the Rectus abdominal muscle - the Brachioradialis muscle and extensor of the wrist ).

- The most important biomechanical variables effecting the velocity of the ball for both the skill of serve and the for hand and back hand strike (vertical speed and horizontal velocity - the amount of vertical and horizontal movement of the center of the weight of the strike arm - the horizontal wheel and the result of the wheel to the position of the center of gravity of the strike arm - the horizontal displacement of the wrist point of the arm Strike - the horizontal force of the center of gravity of the striking arm - the vertical and horizontal velocity of the bat - the sum of the speed and the wheel of the bat - the result of the displacement of the bat Trunk - elbow angle of the striking arm - shoulder angle of the strike arm - racquet angle - ball height).