RA numbers might be misleading sometimes
RA Numbers are not misleading. RA numbers are RA numbers.
The main problem is that a lot of players do not understand that several things can cause tennis related arm injuries.
1 Stroke Technique - If player does not hit the ball properly, the frame will make little difference.
2 IMPACT Shock - This is the shock that is transferred to the player's arm when the ball impacts the string bed or the frame itself. Stiff frames tend to transfer greater levels of this shock to the arm that more flexible frames do.
3 POST IMPACT VIBRATION Shock - This is the shock that is transferred to the player's arm AFTER the ball has impacted the string bed or frame. When the ball hits the racquet, it sets off a series of vibrations in the racquet frame which can be transferred to the arm. Flexible frames tend to vibrate more and for longer than stiffer frames do so they may transfer more of this shock to the arm than a stiff frame will.
4 GENETICS - Some player's arm's are more susceptible to one type of shock over the other. Some are only affected by one. Some are not affected by either.
So it's important that a player knows their own body and bio-mechanics. That makes it a lot easier for a player to then choose what sort of frame and string config is ideal for them from an injury prevention perspective.