Biomechanic Analysis of Lower Extremities in Children and Teenagers with Pes Planus

Shin, Jung Bin; Kim, Seong Woo; You, Sung; Lee, Sun Kyoung; Kim, Hyoung Seop

Abstract

OBJECTIVE
To analyze the biomechanics of young patients with flat foot or malalignment syndrome of lower extremities and to provide some information and strategies in examining and treating them for other researchers or successive studies. METHOD: Between January 2004 and March 2006, 274 patients were engaged who had been diagnosed as flatfoot in 586 patients aged between 0 and 18. All patients were examined physically by one physiatrist to find other biomechanic abnormalities of lower extremities and to measure resting calcaneal stance position (RCSP) angle, bimalleolar angle (BMA). To detect the existence of scoliosis and the difference in leg length, radiographs were taken of the spine and the lower extremities. Flat foot was defined as when either of the feet had lower than -4degrees degrees of RCSP angle.
RESULTS
When comparing the value of RCSP angle between right side and left side, the left side was more pronated than the right side. The value of RCSP angle increased in proportion to age but there are other factors that caused the persistence of foot pronation and ligament laxity. The value of BMA tends to increase in proportion to age. The foot was more pronated, the tibia of the same side was more rotated internally and tibia of the other side was more rotated externally. The most common combined biomechanic abnormality of lower extremities was toe-in gait.
CONCLUSION
Because the biomechanic effect of a foot could influence the leg, pelvis of the same side and the other side lower extremity, the flat foot should be regarded as an element of malalignment syndrome, anatomical abnormality, and also functional impairment.