A case study conducted by the University of Medicine and Dentistry of New Jersey and published in the October 2008 issue of the American Physical Therapy Association's journal found that when a teenage boy with cerebral palsy played Wii Sports as part of his regular therapy, "there were positive outcomes at the impairment and functional levels," according to the abstract.
[T]he patient was a 13-year-old male with spastic diplegic cerebral palsy. In a school-based setting, he participated in 11 training sessions, over a four-week period, using the Wii while continuing to receive physical and occupational therapy. The sessions were each between 60 and 90 minutes long and used the Wii sports games software, which offers boxing, tennis, bowling, and golf. He trained in both standing and sitting positions.
“ 'Improvements in visual-perceptual processing, postural control, and functional mobility were measured after training,'” the researchers reported.