Determinants of Frame Running Capacity in Athletes with Cerebral Palsy to Improve Training Routines and Classification Strategies: A Cross-sectional Observational Study

Objectives The aim of the study were to (1) investigate what physical and physiological parameters are most important for Frame Running capacity, a parasport for individuals with ambulatory difficulties, and (2) determine whether Frame Running capacity can be predicted in athletes with cerebral palsy. Design Athletes with cerebral palsy (N = 62, Gross Motor Classification System I-V; 2/26/11/21/2) completed a 6-min Frame Running test. Before the 6-min Frame Running test, muscle thickness, passive range of motion (hip, knee, ankle), selective motor control, and spasticity (hip, knee, ankle) were measured in both legs. In total, 54 variables per individual were included. Data were analyzed using correlations, principal component analysis, orthogonal partial least square regression, and variable importance in projection analysis. Results The mean 6-min Frame Running test distance was 789 ± 335 m and decreased with motor function severity. The orthogonal partial least square analysis revealed a modest degree of covariance in the variables analyzed and that the variance in the 6-min Frame Running test distance could be predicted with 75% accuracy based on all the variables measured. Variable importance in projection analysis indicated hip and knee extensor spasticity (negative effect), and muscle thickness (positive effect) arose as the most important factors contributing to Frame Running capacity. Conclusions These results are an important resource to enable optimization of training regimes to improve Frame Running capacity and contribute to evidence-based and fair classification for this parasport.