New research finds that people who use weight machines for training are at a higher risk of developing lower back pain than others.
On the other hand, people who participate in callisthenicsm exercise classes and use free weights and are not associated with a higher risk of lower back pain compared to those who don't perform these activities.
The study, published by Sports Medicine Australia in The Journal of Science and Medicine in Sport, used longitudinal data to discover whether flexibility and muscle strengthening activities are associated with a greater risk of lower back pain.
Lead author Dr Robert Sandler, University of Sheffield Medical School stated that previous data and opinion on the effect of stretching on the risk of injury had been conflicting.
"Australian National Physical Activity Guidelines recommend adults do muscle strengthening exercises at least 2 days per week, while similar guidelines are in place in the UK, Canada and United States," Dr Sandler said.
"Despite these recommendations, there are conflicting data and opinions on whether these activities may actually be harmful to the lower back.
"Given that between 70 to 90 per cent of Australians will suffer from lower back pain at some point in their lives, it's important to be aware of how to minimise the risk where possible.
"Our study, which assessed long-term questionnaire and biometric data on thousands of American white collar workers over a period of 5 years, aimed to determine whether any particular activities were associated with the reporting of lower back pain, or provided protection against it.
"Participants who reported regular stretching exercises had a higher rate of reported lower back pain than those who didn't engage in regular stretching.
"Similarly, the regular use of weight training machines was associated with a higher risk of lower back pain compared to free weight use or no muscle strengthening activities."
Dr Sandler said the value of weight machine as opposed to free weight training has long been the subject of much debate.
"Our study suggests that people should incorporate a variety of exercises into their physical training programme rather than exclusively stretching or using weight machines," Dr Sandler said.
"By supplementing weight machine training with free weights, and combing stretching with other flexibility exercises such as callisthenics or other exercise classes, the risk of developing lower back pain may be reduced."