title: Elbow Kinematics During Gait Improve With Age in Children With Hemiplegic Cerebral Palsy.
abstract: BACKGROUND
  Children with hemiplegic cerebral palsy (hCP) exhibit a typical posture of elbow flexion during gait. However, the change in elbow kinematics and symmetry during gait across age span in both hCP and typically developing (TD) children is not well described. The aim of this study was to quantify the change in elbow kinematics and symmetry across age span in hCP children compared with TD children.
  
  
  METHODS
  Upper extremity kinematic data were extracted and analyzed from a database for gait studies performed between 2009 and 2015. A total of 35 hCP and 51 TD children between the ages of 4 and 18 (mean age: TD=11.2±0.6, hCP=9.8±0.5) met inclusionary criteria. The groups were further subdivided into 3 age categories: 4 to 7, 8 to 11, 12+ years old. Elbow angles were extracted and peak elbow flexion, overall range of motion during gait, and asymmetry indices were calculated. A 1-way analysis of variance was performed on each group with post hoc Tukey honestly significant difference pairwise comparisons.
  
  
  RESULTS
  Peak elbow flexion during gait increased with age in TD children (P<0.05) and decreased with age in hCP children on the affected side (P<0.05). There was no change on the less affected side of hCP children. TD children demonstrated significantly less elbow flexion (mean=51.9±2.1 deg.) compared with the affected side in hCP (mean=82.1±3.8 deg.) across all age categories (P<0.05). There was no change in elbow asymmetry index (0=perfect symmetry) across age in either controls or hCP children; however, there were differences between hCP and TD groups in younger age groups (TD=28, hCP=62, P<0.05) that resolved by adolescence (TD=32, hCP=40).
  
  
  CONCLUSIONS
  During gait, hCP children have greater peak elbow flexion on the affected side than do TD children. Peak elbow flexion angle converged between the 2 groups with age, decreasing in hCP children and increasing in TD children. Furthermore, elbow symmetry during gait improves with age in hCP children, approximating symmetry of TD children by adolescence. These findings have implications for both consideration and optimal timing of surgical intervention to improve elbow flexion in children with hCP.
  
  
  METHODS
  Level III-retrospective case-control study.
authors.affiliation: Leon Root, MD Motion Analysis Laboratory, Hospital for Special Surgery.
authors.forename: Benjamin L
authors.initials: BL
authors.lastname: Gordon
authors.affiliation: Leon Root, MD Motion Analysis Laboratory, Hospital for Special Surgery.
authors.forename: Aviva L
authors.initials: AL
authors.lastname: Wolff
authors.affiliation: Departments of Hand & Upper Extremity Surgery.|Pediatric Orthopaedic Surgery, Hospital for Special Surgery, New York, NY.
authors.forename: Aaron
authors.initials: A
authors.lastname: Daluiski
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D002547:Cerebral Palsy / Q000150:complications / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004551:Elbow Joint / Q000503:physiopathology*; D005260:Female; D005684:Gait; D006429:Hemiplegia / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D008297:Male; D016059:Range of Motion, Articular; D012189:Retrospective Studies