Intense neck pain, incontinence and acute tendinitis - sounds like a bad disease, right? According to scientists, these are all actually health problems associated with playing various Nintendo gaming systems.

Following reports of Nintendo-related health problems, Dutch researchers decided to look at all the evidence to ascertain whether a Nintendo is a safe present to give at Christmas.

They searched two medical databases and found almost 40 relevant articles about this issue.

Early reports associated with playing Nintendos ranged from seizures - known as ‘Nintendo epilepsy' - to incontinence in children who were so engrossed in playing, they would not stop to go to the toilet.

Other cases included intense neck pain in a child who was hunched over for 30 minutes playing his Nintendo Game Boy, as well as reports of thumb, hand and wrist problems associated with the use of a traditional controller with buttons or a joystick.

Then in 2006, Nintendo brought out the Wii, which uses a motion-sensitive remote controller. Its most popular game, Wii Sports, involves players swinging these controls around to imitate participation in sports such as boxing and tennis.

The researchers found that the first Wii-related injury involved a 29-year-old man who had been playing Wii Sports for a number of hours and ended up with acute tendinitis of his right shoulder.

The study found that the most dangerous Wii sport was tennis, with common injuries including bruising and lacerations to the hand.

Meanwhile, two patients suffered strokes after playing the Wii, while another required hernia surgery after exercising with Wii Fit.

Despite these reports, the researchers from the University Medical Center Groningen found that overall, given the number of Nintendos that are sold worldwide, most health-related problems are mild and their prevalence is low.

"Overall, a Nintendo is a relatively safe Christmas present. However, those who receive such a gift should not swing the controller too hard, they should be careful about where they play, and they should take frequent breaks," they concluded.

Details of these findings are published in the Christmas issue of the British Medical Journal.