Differences between running-related injury predictors for male and female novice runners

Popular activity, inherent drawbacks
Recreational running is quite possibly the most common form of physical activity throughout the world, and due to its simplistic and flexible nature, can be done by nearly anyone at any time and any place. Despite its beneficial impact on health and wellbeing, however, running also carries with it the risk of running-related injury (RRI), with some studies reporting numbers as high as 79% of all runners sustaining an RRI at some point. Research on exact causes of RRIs is limited, which prompted a randomized control trial that sought to identify gender-specific predictors of RRI in novice runners training for a four-mile run.

Evaluating the risks
Applying inclusion criteria to a large sample size, 486 healthy individuals aged 18-65 who had not run regularly for the past year were used as subjects. Participants were issued baseline questionnaires to assess background information, and were then introduced to an eight- or 13-week training program that consisted of three training sessions per week. Runners were responsible for keeping a log and documenting any RRI--defined as running-related musculoskeletal pain of the lower extremity or back causing a restriction of running for at least one week--or any other running-related pain during the program.

Male/female disparities
Data showed 100 RRIs reported by 486 participants, with the number of injured runners being 20.6 per 100 runners at risk. More importantly, differences were found between injury predictors for males and females. For males, higher body mass index (BMI), previous injury and previous sports participation were all significantly associated with RRI, while for females, the only significant predictor was a high value for navicular drop. The small navicular bone is found in the arch of the foot, and navicular drop is associated with over-pronation, a common condition where the foot rolls inward excessively during running. While excessive pronation is considered abnormal, the correlation between navicular drop and RRI is not fully understood and needs to be further examined, as do additional risk factors for females. Despite this need, it's clear that male and female novice runners experience different risk factors for injury. Prevention measures must therefore be approached independently, as proper footwear and orthotics may address pronation issues for females but other implications are needed for males.

-Summarized by Greg Gargiulo

-As reported in the Dec. '09 edition of The American Journal of Sports Medicine