Lower back pain is a chronic condition that affects hundreds of millions of people around the world. A simple exercise could be a big help.

You know the feeling. You bend down to tie your shoelaces and experience a sharp searing pain in the bottom of your back. Suddenly, you've become part of a startling statistic – you've joined the estimated 619 million people worldwide living with lower back pain. Luckily there is handy exercise which can help, called seated salsa.

And the best thing? You don't even have to get up to do it.

Lower back pain is the leading cause of disability worldwide. It's defined as pain between the lower edge of the ribs and the buttocks. It can affect anyone, but is more common in people who are overweight, smoke, or who have a family history of the condition

"I used to work with spinal surgeons, and if you look at where people have most problems in the back, it's the bottom two discs in the vertebrae," says Chris McCarthy, an associate professor of physiotherapy at Manchester Metropolitan University.

The backbone is made up of 33 vertebrae, each of which is separated by a spongy layer of cartilage called a disc. The discs provide cushioning; they act as shock absorbers during everyday activities such as walking, running and jumping.

The bottom two vertebrae, where most lower back pain is located, are attached to the pelvis with very thick ligaments. This holds them firmly in place, allowing them to do their job of supporting the weight of the torso. However, there is a downside.

"It's a really stiff part of the back, and it's very difficult to get it to move, especially when the local muscles are in spasm due to pain, or tight due to lack of use," says McCarthy.

One good way to exercise the muscles in the region is to rotate the pelvis from one side to the other, which makes the bottom of the back tilt from side to side in a kind of rocking motion. This happens naturally when you walk. However, when a person experiences lower back pain, the back muscles go into a spasm and immobilise the area, stopping it from moving.

"Unfortunately, that creates a vicious cycle where it........

© BBC