In one sentence, describe what the following article is about:

With any kind of forearm tendinitis, it is more common for your dominant hand to be affected, but both arms may be affected. Tendinitis will occur in the tendons against which you consistently exert the most force. Tendinitis may also occur in the tendons that control either extension or flexion (straightening or bending), but it rarely occurs in both at the same time. The repetitive motion that exerts the most stress either force against flexion or against extension will cause tendinitis. Tennis elbow may develop if you exert force against an object with your elbow extended. Although tennis elbow is often caused by playing tennis, using a lighter racquet and a two-handed backhand swing may reduce your chances of developing this condition. Some other types of movement that may also cause tennis elbow include: Repetitive heavy lifting or using heavy tools Jobs that involve the use of squeezing and twisting movements or precision motions New or uncommon movements, such as gardening for the first time in the spring, lifting a new baby, or packing and moving your home Although named after the sport of golf, golfer's elbow can also be caused by other sports that involve gripping and/or throwing motions, such as baseball, football, archery, or javelin throwing. Some other types of movement that may cause golfer's elbow include: Doing jobs that involve repetitive motion of the elbow, including computer use, gardening, chopping or painting Using vibrating tools Using a racquet that is too small or heavy for your ability or putting excessive topspin on the ball Participating in other repetitive activities for an hour or more on consecutive days, such as weight lifting, cooking, hammering, raking, or chopping wood

Summary:
Think about whether you are having symptoms in one or both arms. Identify repetitive movements that may have contributed to your tennis elbow. Consider activities that may have contributed to your golfer's elbow.