Having your neck and your back "cracked" or undergoing spinal manipulations carried out by chiropractors could lead to 'catastrophic' health problems like strokes, warned some experts.

Tens of thousands of patients undergo spinal manipulation every year by trained health professionals in which the back or neck is "cracked" to relieve pain and improve physical function.

However a group of doctors are now saying that this "clinically unnecessary" treatment should be abandoned because it can produce some serious side-effects that affect two in three people at some point in their lives.

Researchers, writing in the British Medical Journal, say the representatives of chiropractors and osteopaths should advise their members the risks outweigh the benefits by too much to justify the use of manipulation.

Expert Dr. Neil O'Connell of the Centre for Research in Rehabilitation at Brunel University said that spine manipulation "may carry the potential for serious neurovascular complications" and that the technique is "unnecessary and inadvisable."

O'Connell said that past studies "provide consistent evidence of an association between neurovascular injury and recent exposure to cervical manipulation."

He said that the most serious potential side-effect is tearing the lining of the vertebral artery in the neck, which can lead to stroke.

While the numbers of patients suffering serious complications vary, most reported cases of side effects have been after chiropractic care rather than osteopathy or physiotherapy, where manipulation is used less often.

"The potential for catastrophic events and clear absence of unique benefit lead to the inevitable conclusion that manipulation of the cervical spine should be abandoned," O'Connell said.

An analysis conducted by Cochrane, an international medical review body, found that manipulation as a stand-alone treatment, provides only moderate short term pain relief compared to sham manipulations or muscle relaxants.

Researchers noted that many side effects may also go unreported, and they found that half of studies for chiropractic treatments failed to mention adverse effects even though there was ample evidence that patients had suffered them.

However, Professor David Cassidy, an epidemiologist from Toronto University in Canada, also writing in the online journal, said that there was more than enough evidence to show that neck manipulation had benefitted patients.

Cassidy wrote that there are numerous studies that "clearly suggest that manipulation benefits patients with neck pain" and raises doubt about any causal (direct) relation between manipulation and stroke.

When combined with recent randomized trial results, "this evidence supports including manipulation as a treatment option for neck pain, along with other interventions such as advice to stay active and exercise."

However, Cassidy acknowledged that when risk, benefit, and patient preference are considered, "there is currently no preferred first line therapy, and no evidence that mobilization is safer or more effective than manipulation. Thus the identification of safe and effective interventions for neck pain remains a high priority."

"We say no to abandoning manipulation and yes to more rigorous research on the benefits and harms of this and other common interventions for neck pain," Cassidy and his colleagues wrote.