A string of beads made of various materials has become a favorite toy among some elementary Chinese school students.

Students rub the beads in class or at home.

It used to be regarded as the preference of adults, especially middle-aged and elderly people.

When asked why they choose to play with the beads, some students said the sound the beads make when they are rubbed or struck together is relaxing.

"Most of my classmates play with the beads, so I joined them, too," said a girl in the ninth grade.

The topic of primary school students' obsession has sparked heated discussions online.

Students show the bead strings they play with. (Photo/video screenshot)

"Obsession with the beads can lead to unbalanced development of finger joints and cause hyperplasia or other diseases. It might also cause premature hyperplasia strain and tenosynovitis, or even irreversible damage," said Lu Liang, a doctor at a Jinan hospital.

Liu Yang, a psychological consultant, said that playing with beads is like playing games or with mobile phones.

"Some children are indulged in games, hoping to realize their own value in the game world. It is a form of stress relief," Liu said. "Therefore, parents and teachers should understand children's behavior and find the right solutions."

Experts suggest that students should listen to soft music, talk with relatives and friends, recall happy things, travel, and eat their favorite foods to adjust their mood.