Chinese speed skating player Zhang Hong performs touching her belly button with her hand from around the back. (Photo/sina weibo)

Can you touch your belly button with your hand by reaching around the back of your body?

The challenge has become an addictive trend on the Internet as women try hard to twist their bodies to complete the feat and show how slim they are, Nanjing-based Modern Express reported.

Experts have warned women to be careful in performing the strange yoga-like move as some have dislocated their shoulders, according to Taiwan's ETTV News.

Xie Wei, a fitness instructor in Nanjing city, Jiangsu province, said some people can perform the difficult move because they are thin, flexible or have long arms.

But being thin doesn't always translate into having a good figure or being beautiful, so a woman touching her belly button by contortion isn't proving her beauty, it was added.

Xie called for women to pay more attention to body proportions rather than joining online waist wars.

A doctor also said it's dangerous for women to suddenly push their body limits, which can lead to dislocation of limbs.