Having a stretch before a running exercise does not aid injury prevention, according to a study presented at the 2011 Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS).

The study looked into the habits of 2,729 people - regular runners who do 10 or more miles per week. Of the sample group, 1,366 were randomized to a stretch group, and 1,363 were randomized to a non-stretch group.

Runners in the stretch group stretched for up to five minutes and muscle groups that were worked on included quadriceps, hamstrings, and gastrocnemius/soleus muscles.

The study found that group that stretched before running had no less injuries than the non-stretching one.

Instead, the study identified a number of other significant risk factors for injury - such as history of chronic injury; higher body mass index; and switching pre-run stretching routines. Runners who typically stretch as part of their pre-run routine and were randomized not to stretch during the study period were far more likely to have an injury.

Daniel Pereles, study author and orthopaedic surgeon from Montgomery Orthopedics outside Washington, DC, US, said: "We found that the risk for injury was the same for men and women, whether or not they were high or low mileage runners, and across all age groups.

"The more mileage run or the heavier and older the runner was, the more likely he or she was likely to get injured, and previous injury within four months predisposed to even further injury."