Yoga may not be as 'safe' as first thought, with a study finding it can cause musculoskeletal pain just like any other exercise.

Yoga can help relieve those aches and pains but it can also lead to an injury, researchers warn.

A University of Sydney found yoga caused musculoskeletal pain - mostly in the arms - in more than 10 per cent of participants.

Yoga also exacerbated 21 per cent of existing injuries.

Lead researcher Associate Professor Evangelos Pappas says the risk of pain caused by yoga is higher than previously reported.

"Yoga may be a bit more dangerous than previously thought," Prof Pappas told AAP.

"Our study found that the incidence of pain caused by yoga is more than 10 per cent per year, which is comparable to the injury rate of all sports injuries combined among the physically active population," he said.

The prospective study assessed more than 350 people who attended yoga classes at two studios in New York.

Participants, mostly women with an average age of 45, were asked to complete a questionnaire at recruitment and again after one year.

Most of the "new" pain (13.3 per cent) reported was either in the shoulder, elbow, wrist or hand.

Prof Pappas, who himself is a yoga instructor, says this makes sense because the upper limbs were not designed to support a lot of weight.

"And in yoga you actually you have a lot of these inversions, the downward dogs, that put lots of weight on the upper extremities," he said.

The good news, however two-thirds, or 74 per cent, did report yoga improved pain in the lower back and the neck.

The findings are published in the Journal of Bodywork and Movement Therapies.

Given yoga's popularity and perceived safety, it's important that participants treat it like any other exercise, says Prof Pappas.

"These findings can be useful for clinicians and individuals to compare the risks of yoga to other exercise enabling them to make informed decisions about which types of activity are best," said Prof Pappas.

It's recommended that yoga participants discuss any pre-existing pain, especially in the upper limbs, with yoga teachers and a physiotherapist to explore posture modifications.