The position of the foot just before ground contact during running and walking may put people at risk for ankle sprains, according to a new study published by a University of Georgia kinesiology researcher.
The results of the study, which appear in the June 2011 online edition of the American Journal of Sports Medicine,1 found that people who have a history of repetitive ankle sprains demonstrated lower clearance heights between their feet and the floor during running, and pointed their toes down more during walking. Ankle sprains are the most common sports-related injury, and many who experience a sprain will go on to develop chronic instability, suffering repeated sprains during their lifetime.
"Almost everyone who is physically active will suffer an ankle sprain at some point," said the study's lead author, Cathleen Brown Crowell, an assistant professor in the UGA College of Education's department of kinesiology.
"Many people develop repetitive ankle injuries that are painful, can decrease performance and increase the risk of ankle osteoarthritis. We were able to identify 
in foot positioning prior to contact with the ground that may pre-dispose some people to these repetitive injuries. These findings can help clinicians develop rehabilitation programs that address movements that may have been ignored in the past."
Study details
The study collected data on more than 30 male recreational athletes, some with a history of repetitive ankle sprains and some without. Motion capture equipment analyzed joint movements and forces in the participants during walking and running. This study was unique in that it analyzed all three possible motions of the ankle, and included participants who had different types of ankle instability, explained Brown Crowell.
While such motion capture equipment may not be available for analysis of patients in rehabilitation clinics, the findings can be applied to physically active individuals at any level who sprain their ankles.
"We can apply our findings to clinical practice," said Brown Crowell. "Our study demonstrates there are differences in movements at the foot and ankle in an injured population, which may respond to rehabilitation interventions beyond typical stretching and strengthening. The next step is to see if targeted interventions, trying to influence how people run and walk, can treat and even prevent ankle sprains."
Source: University of Georgia
1. Brown C. Foot Clearance in Walking and Running in Individuals With Ankle Instability. Am. J. Sports Med. 2011(10) (accessed July 6, 2011)
