Effects of severity of gross motor disability on anticipatory postural adjustments while standing in individuals with bilateral spastic cerebral palsy

• Anticipatory postural muscle activities are smaller in individuals with BSCP.
• Lower leg muscles play minor roles in APAs in individuals with BSCP.
• Individuals with more severe BSCP exhibit more proximally extended APA deficits.

BackgroundAlthough individuals with bilateral spastic cerebral palsy (BSCP) exhibit several deficits in anticipatory postural adjustments (APAs) while standing, effects of severity of motor disability on their APAs are unclear.AimsTo determine whether individuals with BSCP exhibit severity-dependent deficits in APAs.Methods and proceduresSeven individuals with level II BSCP (BSCP-II group) and seven with level III BSCP (BSCP-III group) according to the Gross Motor Function Classification System and seven healthy controls lifted a load under two different load conditions.Outcomes and resultsAnticipatory activities of the erector spinae (ES), medial hamstring (MH), and gastrocnemius (GCM) were smaller in the two BSCP groups than in the control group. Although the anticipatory GCM activity was similar between the BSCP groups, the ES and MH activities were larger in the BSCP-II group than in the BSCP-III group. In the BSCP-II group, an increase in anticipatory activity with an increase in load was observed in the MH, but not in the GCM. In the BSCP-III group, load-related modulation was not found in the MH or GCM.Conclusions and implicationsThe present findings suggest that in individuals with BSCP with severe motor disability, APA deficits extend to more proximal parts of the body.