You knew it was a matter of time.

Taken from NEJM:

To the Editor: In 1990, Brasington described "Nintendinitis" in a patient with pain over the extensor tendon of her thumb after 5 hours of playing a Nintendo video game. Nintendo next released the highly popular Wii games console that includes a wireless remote capable of detecting movement in three dimensions. Clinicians began to see patients with "Wiiitis." There do not seem to be reports of associated bony injuries, although interactive gaming has been reported to aid in the rehabilitation of patients after fracture.

In the United Kingdom, a healthy 14-year-old girl presented to the emergency department at Horton General Hospital in Banbury (near Oxford), having sustained an injury to her right foot with associated difficulty in mobilization. She had been playing on her Wii Fit balance board and had fallen off, sustaining an inversion injury.
(The Wii Fit replaces handheld controls with a pressure-sensitive board about 2 in. off the ground that lets the user participate in tricky games that can improve balance.)

On examination, there was soft-tissue swelling around the base of the fifth metatarsal, which was maximally tender to palpation. A radiograph showed a small fracture of the base of the fifth metatarsal (Figure 1). The patient was treated conservatively with the use of crutches and was referred to the fracture clinic for outpatient follow-up. The fracture probably resulted from the pull of the peroneus brevis muscle during inversion of the ankle.

What we all need next is some idiot to file a lawsuit against Nintendo...