title: Physiological knock-knee in preschool children: prevalence, correlating factors, gait analysis, and clinical significance.
abstract: Physiological knock-knee (PKK) was categorized by measuring intermalleolar distance (IMD), a clinically simple method, to evaluate the prevalence and correlating factors in 305 preschool children. The prevalence in this cross-sectional study was relatively high, and it was age related (p = 0.002; 64, 44, and 34% for ages 3-4, 4-5, and 5-6 years, respectively). The following factors were correlated with PKK: use of walking chair early (p = 0.0001), independently walked late (p = 0.0005), dependently walked longer (p = 0.0001), concurrence with flatfoot (p = 0.001), and angular deformity (toe in/out, p = 0.03). Gait analysis, with spatiotemporal, kinematics, and kinetics parameters, was performed to evaluate the ambulatory significance. Preschool children with PKK have a shorter stride length (p = 0.02) and a slower walking speed (p = 0.004). Dynamic hyperextension of the knee is noted for 8 degrees during the whole gait cycle (p < 0.05). We conclude that PKK is a variable that should be considered in the development of mature gait for preschool children.
authors.affiliation: Department of Surgery, National Cheng Kung University Medical College, Tainan, Taiwan. mark@mail.ncku.edu.tw
authors.forename: C J
authors.initials: CJ
authors.lastname: Lin
authors.forename: S C
authors.initials: SC
authors.lastname: Lin
authors.forename: W
authors.initials: W
authors.lastname: Huang
authors.forename: C S
authors.initials: CS
authors.lastname: Ho
authors.forename: Y L
authors.initials: YL
authors.lastname: Chou
mesh_terms: D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D005413:Flatfoot / Q000150:complications; D005684:Gait; D006801:Humans; D016916:Joint Deformities, Acquired / Q000150:complications / Q000503:physiopathology*; D007719:Knee Joint; D008297:Male