"Except for my spinal disk, I have nothing outstanding."

This is a joke often told by Chinese people who have herniated disks, as the same two-character word, tuchu (突出) describes something wonderful and something bulging out in Chinese language.

According to the latest statistics from the National Health Commission of China), more than 200 million Chinese are suffering from lumbar disk disease.

Backaches caused by the disease, or lumbar muscle strain can be very common among people aged 18-60.

Here's something you should know about herniated disks from Guo Jingwei, chief physical therapist from the China-Japan Friendship Hospital, and his advice on how to protect your lumbar spine.

Q: Which age group is more vulnerable to lumbar disk disease?

A: People aged 35-55. The disease is commonly caused by aging and sometimes severe back injuries. After 35, the chance of disk herniation occurring will be much greater. It may happen as a result of genetic factors, heavy work, and maintaining the wrong posture over a longer period of time. Manual workers, drivers and those who need to sit for a long time as well as overweight people are prone to the disk disease. But after 60, the risk of disk herniation declines.

Q: Are there other factors causing disk herniation?

A: Obesity and smoking.

Q: Once young people get lumbar disk disease, will the chance of recurrence be higher as they grow older?

A: It depends. Some people with the disease may have very severe symptoms when young, yet are healthy in old age.

Q: Do people have to see doctors when they have a herniated disk?

A: If the symptoms are not that serious and the pain could be released through rest and exercises, they can choose not to go to the hospital. But if more severe pain occurs, it is necessary to turn to medical help in time, in case the situation worsens.

Q: How can rehabilitation help patients with this disease?

A: Apart from giving the patients necessary remedies, we help patients get to know the contracture of the spine and lumbar region and adjust their wrong posture. Then physical therapy will be given if needed.

Q: Is the Superman exercise -- known in China as flying swallow, or xiao yanfei -- safe? It is highly recommended for people with lumbar disk disease, yet now many have said it could cause more back pain.

A: To people who have disk herniation, especially during the most severe period, the Superman exercise is definitely not recommended. Healthy people could practice the Superman to make the back muscles stronger.

Q: Will practicing yoga cause disk herniation?

A: No exercises would directly cause disk herniation. Moderation is the key factor. Even nectar is poison if taken in excess.