From hip to ankle in the sagittal plane: evidence for generalized proprioceptive deficits in children with unilateral and bilateral spastic cerebral palsy through 3D motion analysis

Abstract

Background & objectives: Proprioceptive deficits affect 46-82% of children with cerebral palsy (CPc), yet evidence largely derives from upper-limb studies while lower-limb deficits remain underexplored. Previous studies often assess a single joint and rarely account for age, limiting understanding of whether deficits are generalized across joints and sides or localized compared with typically developing children (TDc) and across CP subtypes. Methods: Hip, knee, and ankle proprioception were assessed using passive-ipsilateral Joint-Position-Reproduction (JPR) in the sagittal plane in 32 CPc and 30 TDc (5.1-12.8 years). Joint Reproduction Error (JRE,degrees) was calculated from 3D kinematics for both legs. Group- and age-related differences in JRE were analyzed using general linear models, and subgroup and limb-related differences using one-way ANOVA and paired t-tests. Results: CPc showed larger JRE values than TDc across all joints (p < 0.01). JRE values were similar across CP subtypes, except for the dominant knee and hip, which did not differ from TDc in unilateral CPc. JRE decreased with age for the knee across groups (p < 0.01), although age-related findings should be interpreted cautiously given the sample size. Conclusion: CPc show proprioceptive deficits across multiple lower-limb joints, with comparable severity but different distribution patterns across subtypes. Inter-individual heterogeneity persists, highlighting the need for multi-joint assessment and patient-tailored treatment.