For many years the approach to flat feet in children and teens has been to recommend arch supports and special, highly supportive, shoes. But more recently, such measures have come to be viewed as ineffective, embarrassing and uncomfortable.The four groups, representing varying arch index degrees from normal to flat did not differ in any of the performance areas.
The investigators hypothesized that if flat footedness is related to poor lower leg function and increased sports injury, they should be able to demonstrate impaired motor abilities of the lower leg in children with flat feet. They designed a study to evaluate the impact of flat feet in 11-15 year-olds on a series of skills directly related to athletic performance.
They studied 218 children in the fifth through eighth grades who did not have any lower limb pathology or other underlying conditions. Computerized scans were used to determine the arch index, a measurement of the height of the arch. The influence of age on expected arch development was statistically corrected for and the children were divided into four groups based only on how their arch indices related to a normal measurement. The groups ranged from those with normal arches, to those with no arches, with two intermediate groups subdividing those with less than normal, but not totally flat indices. Groups were found to be similar in age, gender and participation in sports activities.
Children were tested on 17 measures of athletic performance using equipment in a sports diagnostic center. Tasks included: jumping, hopping, tip toe standing, balancing back to front and side-to-side, balancing on one leg and lower leg repetitive movements. Performance tests included measures of starting speed, acceleration, power, reaction time and balance Within each test, if appropriate, they measured maximal speed, height, and force, leg stiffness, and markers of neuromuscular control.
The results were striking. The four groups, representing varying arch index degrees from normal to flat did not differ in any of the performance areas. Significantly, the group with the least flat feet and the group with the flattest feet showed no statistically significant difference in any sports related motor performance.
The question of the relationship of flat feet to injury has also been debated. It is possible that that high arches and low arches predispose to different, though not necessary more, lower extremity injuries. The authors cite a study of runners that found that those with high arches had plantar fasciitis, lateral ankle sprain and ilio-tibial band syndrome. Low-arched runners had knee pain, patellar tendonitis and plantar fasciitis.
The relationship between flat feet and acute or overuse injuries remains unclear, but the authors of this study suggest that if the form of the foot itself does not affect motor skills, it might not affect injury patterns either. This is clearly an area for further study.
The authors definitively conclude that there are no disadvantages for sports performance or ability originating from flat footedness in 11-15 year-olds, and they strongly question the advisability of using corrective insoles just for the purpose of improving athletic performance. It may be appropriate for parents to get more than one opinion to evaluate treatment recommendations for their flat-footed young athletes.