To Örebro University

Cerebral palsy (CP) is considered the most common cause of physical disability in childhood. Most children will walk, but gait often deteriorates with growth and development. Walking with excessive knee flexion is commonly described, one cause being knee flexion contracture (KFC), which can progress to the extent that it restricts the child’s walking ability. The aim of this thesis work was to validate two-dimensional markerless (2D ML) gait analysis in assessing knee flexion angles during gait in children with CP. Also including analyzing if and to what extent KFC impacted the result of orthopedic surgery and studying the prevalence of KFC and its association with common physical functional measures. Another aim was to explorethe feasibility of the 2D ML assessment. Children with CP, gross motor function classification scale (GMFCS) level I, II, III (Studies I, II and IV), IV and V (Study III) were included. 2D ML, using a single video camera with computer processing (I, IV), and 3-dimensional gait analysis (3D GA) (I, II) were used. Pre- and postoperative physical examination and gait analysis data were analyzed retrospectivelyand compared between two surgically matched groups based on theseverity of preoperative KFC (II). KFC, functional mobility scale(FMS), standing and transfer ability were assessed and their associations explored (III). The 2D ML method was used, to explore its usefulness in analyzing children with CP in different regions in Sweden (IV). The 2D ML method was found to overestimate the knee kinematics by between +3.3 and +7.0 degrees. The within-method reliability for both 2D ML and 3D GA showed mostly good to excellent results (I). In Study II, both group 1 with no/mild KFC and group 2 with moderate KFC showed significant improvements for all variables studied, except KFC, gait speed and gross motor function assessment in group 1. The prevalence of KFC was 27%, and increased KFC was associated with higher age and GMFCS level (III). A strong association was found between KFC and decreased physical function with lower FMS level and decreased standing and transfer ability(III). In Study IV, assessment of gait speed, step length and knee kinematics could be performed in a practical and reliable way and common mild to severe gait deviations could be identified.