Selective motor control differences in the lower extremities and their relation to trunk control and balance in children with unilateral and bilateral spastic cerebral palsy.

The aim of this study is to investigate the difference of the selective voluntary motor control (SVMC) in the lower extremity and association of SVMC with trunk control and postural balance in children with spastic cerebral palsy (CP), both unilateral and bilateral. The study involved 58 children aged 5–18 with mild to moderate spastic CP (31 unilateral, 27 bilateral). Demographic data were recorded, and lower extremity SVMC was assessed using the Selective Control Assessment of Lower Extremity (SCALE) scale. Balance responses and trunk control were evaluated with the Pediatric Balance Scale (PBS), and the Trunk Control Measurement Scale (TCMS), respectively. Compared to children with bilateral CP, those with unilateral CP showed higher performance in SCALE (d = 0.84, 95% CI 0.30–1.37), TCMS (d = 1.61, 95% CI 1.02–2.21), and PBS (d = 1.84, 95% CI 1.22–2.46). Children with bilateral CP had significantly lower SCALE total, hip, and knee scores than those with unilateral CP (p < 0.01). In unilateral CP, SCALE total scores moderately correlated with TCMS scores (r = 0.49), while in bilateral CP, strong correlations were found with both TCMS (r = 0.90, p < 0.001) and PBS (r = 0.89, p < 0.001) scores. These findings indicate that SVMC characteristics differ between unilateral and bilateral CP. The results raise the hypothesis that distinct underlying motor control impairments may require different rehabilitation strategies. Future studies are warranted to investigate how interventions can be tailored according to CP type and to examine longitudinal changes in SVMC.