Validation of a multisegment foot and ankle kinematic model for pediatric gait

This paper reports the development, accuracy, reliability, and validation protocol of a four-segment pediatric foot and ankle model. The four rigid body segments include: 1) tibia and fibula; 2) hindfoot--talus, navicular, and calcaneus; 3) forefoot--cuboid, cuneiforms, and metatarsals; and 4) hallux. A series of Euler rotations compute relative angles between segments. Validation protocol incorporates linear and angular testing for accuracy and reliability. Linear static system resolution is greatest in the Y orientation at 0.10 +/- 0.14 mm and 0.05 level of significance and 99.96% accuracy. Dynamic linear resolution and accuracy are 0.43 +/- 0.39 mm and 99.8%, respectively. Angular dynamic resolution computes to 0.52 +/- 3.36 degrees at 99.6% accuracy. These calculations are comparable to the Milwaukee adult foot and ankle model.