10% to 50% of persons who regularly play tennis will, at some time, experience symptoms characteristic of the tendonitis "tennis elbow ". To avoid  the onset of  this  tendonitis   some modifications to technique are necessary.  The   single handed return stroke can be the cause of the pain. Learning the use of the double handed stroke is often useful in avoiding the onset of tennis elbow. The racquet also plays a large role in controlling excessive load forces. A midsized (90 to 100 square inches of hitting zone), medium-flex racquet of lightweight materials offers some protection. Grip size is also an important element: it is important to measure the length (according to the Nirschl technique*) of ring finger along the radial border from the proximal palmar crease to the ring finger tip. The quality of the balls with which you play is also  important: “extra heavy and/or hard" balls could lead to "tennis elbow".