ABSTRACT
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.
