["Tennis leg"--calf muscle rupture of the middle-aged tennis aficionado].

During tennis, the patient heard a bang from his left calf. The inferior edge of the calf muscle at the musculotendinous junction of the medial branch of m. gastrocnemius was tender to pressure, indicating a rupture called as "tennis leg". Foot movements are usually normal, but moving about is painful. The finding is confirmed by ultrasonography. First aid will limit the injury, and when the pain allows, active exercise therapy is initiated. Healing occurs in 2 to 6 weeks, the more difficult ones in 3 to 4 months. Return to the court may take place gradually with a bandaged calf.