The belief that foot pronation, or rolling inward of the ankles, increases the risk of injury in novice runners and requires correction with special shoes is being challenged by biomechanics experts.
Running shoe sales pitches tailor shoes to people based on providing "stability" shoes that offer support to the feet of people who "pronate," tipping the ankle toward the inside of the step.
"What you can see if you don't have the right shoe, if you will, is down the road is some injuries that can plague folks that are pronators, which is the vast majority of us," said Bryan Smith, a manager at Running Room in Toronto.
The sales strategy has been used for 30 years. An estimated 73 per cent of cross-country runners say compatibility between foot posture and shoe design is the key factor when choosing a running shoe, Danish researchers reported in a recent issue of the British Journal of Sports Medicine.
"I wear only one kind of shoe, and that's the shoe that I found works for me," said Toronto runner Ginny Wilkins, who has a bad back.
Sten Rasmussen of the Orthopedic Surgery Research Unity at Aalborg University Hospital in Denmark and his team followed 927 novice runners for a year after evaluating participants' foot posture and grouping them by degree of pronation.
"Pronators had a significantly lower [number] of injuries per 1,000/km of running than neutrals," the researchers concluded.
"The results contradict the widespread belief that foot pronation is associated with an increased risk of running-related injury."
Biomechanics professor Benno Nigg at the University of Calgary also studies pronation in running, which he said is a normal movement of the foot.
"The only thing that we found that had a significant and substantial effect in reducing injuries was comfort," Nigg said.
The Danish researchers also suggested comfort may be a "more relevant criterion for healthy persons on which to base their choice of a running shoe."
To judge a comfort fit, experts suggest taking new running shoes out for a road test.
Training characteristics are also considered important to prevent injuries, the Danish team said.
In the study, the researchers acknowledged that the recovery period after injury to one leg was not fully accounted for when analyzing distances for the other leg.
They said it's also possible that foot pronation may be associated with increased risk of running-related injury if other methods are used to assess pronation.
The study was funded by Aarhus University and the Danish Rheumatism Association.