Dynamic pedobarography for children: use of the center of pressure progression.

BACKGROUND: Although pedobarography has been widely used in quantitative clinical gait analysis for children, the collection, processing, analysis, and interpretation of the data vary widely. In most cases in children, foot dysfunction during gait is primarily a consequence of skeletal segmental malalignment, which can be characterized by the location and duration of the center of pressure progression (COPP) relative to the foot. This study determines the validity and reliability of a technique using the COPP and establishes a normative database for the COPP in children. STUDY DESIGN: Prospective case series to evaluate a diagnostic test. METHODS: Simultaneous pedobarograph and kinematic data collection was performed on 23 children (46 feet) who were neurologically healthy. The validity of the COPP technique was determined by comparing the pedobarograph- and kinematic-based determinations of the orientation of the longitudinal (or long) axis of the foot, an essential component of the COPP approach. Intrarater and interrater reliability for the pedobarograph-based technique were determined by comparing repeated measures of the long axis of the foot from 4 analysts. Normative data for the location and duration of the COPP were generated from this cohort of neurologically healthy children. RESULTS: The mean difference for the long axis of the foot between the pedobarograph- and kinematic-based methods was 2.3 degrees (P < 0.001). The mean difference between first and second determinations of the long axis of the foot by the same analyst was 1.0 degrees (P < 0.001; correlation coefficient, 0.975). The mean difference between the 4 analysts' determinations of the long axis of the foot was 1.9 degrees (P < 0.001; correlation coefficient, 0.969). The normal COPP is located under the heel segment for 23.7% of stance, under the midfoot segment for 28.7% of stance, and under the forefoot segment for 47.5% of stance. CONCLUSIONS: This study establishes clinically acceptable validity and reliability for the pedobarograph COPP technique and determines the location and duration of the COPP in a cohort of neurologically healthy children. CLINICAL RELEVANCE: This standardized approach to the determination of foot loading patterns, based upon normative data, should facilitate the characterization of abnormal foot loading patterns, clinical decision making, and the assessment of outcome after a variety of interventions.

Prevalence of obesity in ambulatory children with cerebral palsy.

BACKGROUND: According to the most recent data, an estimated 17.1% of children in the United States are obese. We found no published studies documenting the prevalence of obesity in ambulatory children with cerebral palsy. The purpose of this study was to document the prevalence of obesity in ambulatory children with cerebral palsy and examine the trend in this measure over the last decade. METHODS: A retrospective review was performed to analyze the age, gender, height, weight, physical classification of the cerebral palsy, and functional level as determined with the Gross Motor Function Classification System (GMFCS) of all children with cerebral palsy who had a gait analysis performed in the Motion Analysis Laboratory of our institution between January 1994 and December 2004. This information was used to determine the prevalence of obesity (a body mass index in or above the 95th percentile of the sex-specific body mass index-for-age growth chart) in this population and its relationship to age, gender, the physical classification of the cerebral palsy, and the GMFCS level. RESULTS: When the data were grouped into three time periods (1994 to 1997, 1998 to 2002, and 2003 to 2004), a significant increase in obesity over time was noted (p = 0.017). The prevalences increased from 7.7% to 14% to 16.5% in the respective time periods. The prevalence increased over time in both males and females, those with hemiplegia and those with diplegia, and those with level-I function and those with level-II function according to the GMFCS. The association between obesity and time was significant in the female (p = 0.015), hemiplegic (p = 0.049), less than eight-year-old (p = 0.020), and GMFCS level-II (p = 0.003) groups. We found that the time period was independently associated with obesity when we controlled for age, type of cerebral palsy, and GMFCS level (p = 0.014). Children with a lesser degree of involvement (GMFCS level II) had twice the odds of becoming obese than did children with greater involvement (GMFCS level III). CONCLUSIONS: The prevalence of obesity in ambulatory children with cerebral palsy has risen over the last decade from 7.7% to 16.5%, an increase that is similar to that seen in the general pediatric population in the United States. This finding may have a major impact on the general health and functional abilities of these children as they reach adult life.