The Importance of the Hands and Wrists in Tennis:

What is the role of the hands and wrists in tennis?
The hands grip the racket and the muscles of the wrist deliver the power generated by the body and control the stroke. A strong grip and wrist muscles are needed to counter the forces developed by the contact with the ball and to develop 'head speed' so important for power..

How do you strengthen the hand and the wrist muscles and ligaments?
Wrist curls and reverse wrist curls will develop the muscles of the hand and the wrist. For pure strength, use 1-2 repetitions 1 set and for anaerobic power or muscular endurance use 6-8 reps and 2 sets at 2 different weights. These exercises have been shown to significantly increase 'head speed'.

What is the most common injury to the hand and the wrist?
Tendinitis of the wrist is probably the injury of greatest concern. The pain can become a major distraction to all of the strokes. With practice sessions of 3-4 hours, this is the equivalent of a repetitive motion injury. These types of injuries are sometimes almost impossible to get rid of so you need to concentrate on prevention on day one. Probably the best way to prevent this injury is to develop pure strength in the hands and wrists and to make sure your stroke mechanics and point of contact are good. As a major participant in racquet sports, I also use an elastomagnetic wrap both on and off the court.