The reason why 'lateral epicondylitis' is called 'tennis elbow' is because many tennis players suffer from this condition.

As in the first image, when receiving the ball with a backhand, the speed of the ball that has been crossed from the opponent's court is transmitted to the racket. Due to this force that pushes the racket back, the forearm extensors from the upper part of the lateral epicondyle (tip of elbow) to the back of the hand are subjected to increased tension, and if the muscles are not properly managed and tightened, they cannot control the tension properly. Thus, increasing the risk of developing elbow problems.

The risks increase further if the lateral muscle chain from the back of the shoulder to the outside of the arm (See 2nd image) is not strong enough, or if the play is made beyond what this chain can handle. For example, say my outer muscles chain is at a level where I can take on 180km/h and my opponent continues to serve at 200km/h. In this case, my forearm muscles are likely to be overloaded, which can develop tennis elbow symptoms. Therefore, tennis players need to reduce the load by supporting the racket with both hands like the third picture, where possible.