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

Background & objectives: Proprioceptive deficits affect 46–82% of children with cerebral palsy (CPc). Deficits in the lower limbs, especially in bilateral CP, remain underexplored. Studies in unilateral CP lack comprehensive assessments, focusing on one joint on the affected side, while overlooking age-related changes. This limits our understanding of lower limb proprioception in CPc, especially whether deficits are generalized (multiple joints, both sides) or localized, compared to typically developing children (TDc) and across CP subtypes. Methods Hip, knee, and ankle proprioception were assessed by the passive-ipsilateral Joint-Position-Reproduction (JPR) method in 32 CPc and 30 TDc (5.1–12.8 years). Joint Reproduction Error (JRE,°) was calculated from 3D kinematics for the dominant and nondominant leg. Group (CPc/TDc)- and age-related differences in JRE were analyzed using a general linear model. Subgroup and limb-related differences were analyzed using one-way ANOVA (unilateral/bilateral CPc/TDc) and paired t-test (dominant/non-dominant leg). Results Age-related improvement in proprioception, as in TDc, appeared only for knee in CPc (F = 7.5–8.7, ηp²=0.12–0.14, p < 0.01). CPc exhibited poorer proprioception across all joints compared to TDc (F = 4.1–19.1, ηp²=0.07–0.25, p < 0.05), with similar deficits in both subtypes (F = 4.5–9.6, η²=0.11–0.25, p < 0.05), except for the dominant knee and hip, which were unaffected in unilateral CP and significantly different from non-dominant side (t=-3–2.5, p < 0.01). Conclusion Generalized proprioceptive deficits were present in 81% of children with CP, affecting multiple lower limb joints in both subtypes. While severity was similar in unilateral and bilateral CPc, the distribution differed: in bilateral CPc, deficits affected both sides equally, whereas in unilateral CPc, only the ankle was bilaterally involved. Substantial inter-individual variability underscores the need for comprehensive assessment and patient-tailored treatment.