When playing tennis, there are a number of joints that are at serious risk:

• Your knees: you are making a lot of lateral (side-to-side) movements that are very hard on your knees.
• Your back: much of the power in your shots come from your movement, which involves twisting at the hips and back.
• Your shoulders: every overhand, underhand and backhand rotates your shoulders, sometimes dangerously.
• Your elbows: tennis elbow is one of the most common injuries for tennis players.
  

When you warm up, it's important that you stretch your legs and back, but it's your arms and shoulders that need the most attention! Below are a few stretches that will help you avoid injury when playing tennis:

Shoulder Rotations

Extend your arms to the side and begin to rotate your arms in small circles. Rotate forward for 20 seconds, then rotate your arms backward for another 20-count. Now rotate in large circles, feeling the movement in your shoulders. Do 20 seconds forward, and 20 seconds backward. This will loosen up your shoulders, reducing shoulder impingement and other injuries.

Deep Tricep Stretch

Your triceps are going to take quite a beating during the tennis match, and stretching them out can help to reduce the strain on your elbows. Raise your right arm over your head, bend the elbow, and touch your hand to your upper back. Grasp the bent elbow with your left hand, and bend to the left. You should feel the stretch all along your side. Hold for 20 seconds, then repeat with the other arm.

Posterior Shoulder/Tricep Stretch

Yet another stretch to loosen up your shoulders, but it will hit your triceps nicely as well. Stand with a straight back, and cross your right arm (keeping it straight) across your chest. Using your left arm, pull the right arm towards your body. Feel the stretch, and hold for 20 seconds before repeating it with the left arm.

Forearm Stretches

These stretches will help to loosen up the muscles of your forearm, ensuring that they won't pull tight and strain your elbow. First, extend your arm, palms up, and bend the hand backward. Use your left hand to pull the fingers of your right hand toward you, and hold the stretch for 20 seconds. Repeat with the left hand. Second, extend the arm, palms down, and bend the hand forward. Use your left hand to pull the fingers of your right hand toward you, and hold for 20 seconds. This will stretch the forearm, wrist, and elbow muscles from both angles.

Once you're done with these stretches, here are a few exercises you can do--using light weight and few reps--to get those elbows and arms ready for tennis:

• Overhead triceps extensions
• Lateral raises (with dumbbell or cable)
• Front raises (with dumbbell or cable)
• Bicep curls
• Wrist Curls
• Pushups

Doing a few exercises before playing tennis won't tire out your muscles, but it will warm them up--reducing your risk of injury on the court!