Carrying heavy backpacks is bad for the spine, a new study has concluded.

A report from the Mount Sinai Medical Centre in the US has concluded that youngsters are suffering because they carry heavy backpacks in the wrong way.

It said that the combination of weight and carrying them over just one shoulder can be harmful, leading to neck and shoulder problems.

Also, MRI scans have revealed that such bags can cause spinal curvature.

Doctors at the centre said this could cause damage to discs that will have major repercussions in adulthood.

Those who have a bad back as a result of injuries sustained earlier in life may find that using ultrasound treatment helps to ease the pain caused by their conditions.

Sportsmen who have suffered recent back injuries include Australian cricketer Peter Siddle, who will miss the rest of the domestic season and the tour to New Zealand with a stress fracture.