Foot and ankle instability is unrelated to cavovarus, flat or neutral foot types

Investigators also confirm reliability of a recently proposed diagnostic test for ankle instability.

TORONTO — The type of feet a patient has — cavovarus feet, flat feet or feet in neutral alignment — does not appear to influence their risk of foot and ankle injuries, according to the preliminary findings of a study presented here.

Gurpal Ahluwalia, MD, and colleagues in Ohio took measurements of both ankles of 523 athletes who participated in various sports at the University of Dayton. The researchers investigated whether any of the foot types had a higher injury rate compared to the others. They also evaluated the inter-observer reliability of a recently proposed diagnostic test for determining patients' malleolar indices, and whether the malleloar index was different among injured athletes vs. non-injured athletes for each foot type, according to the study.

In the study, two medical students and two orthopedic surgeons measured the patients' malleolar indexes and each also measured 17 athletes to serve as controls.

Ahluwalia presented the results at the American Orthopaedic Foot and Ankle Society 23rd Annual Summer Meeting.

"The intra-class correlation coefficient (ICC) in our study for inter-observer reliability was 0.919. This means that there was slight variation between the observers, but overall they were measuring from the same point to the same point for each participant," Ahluwalia said.

Overall, 7.6% of athletes had subtle cavovarus feet, 26.7% had flat feet and 65.7% had neutral feet, according to the study.

Investigators found an overall injury rate of approximately 39%, Ahluwalia said.

Among athletes with a malleolar inidex of 1.3 or greater, those with flat feet had a 28% injury rate, those with cavovarus feet had a 23% injury rate and those with neutral alignment had a 24% injury rate, according to the study.

"The injury rates for the individual foot types were not significantly different from one another," Ahluwalia said. "In our study, athletes with a malleolar index of greater than or equal to 1.3 did not have a significantly higher injury rate than the entire group."

For more information:
Gurpal Ahluwalia, MD, can be reached at Wright State University, Miami Valley Hospital, 128 E. Apple St., Suite 2830, Dayton, OH 45409; 937-208-2127; gurpal.ahluwalia@wright.edu. He has no financial conflicts to disclose.
Ahluwalia G, Laughlin R, Konstantakos M, et al. Anatomic predictors of ankle instability in college athletes. Presented at the American Orthopaedic Foot and Ankle Society 23rd Annual Summer Meeting. July 13-15, 2007. Toronto.