Motor function at increasing postural demands in children with bilateral cerebral palsy

Among children with cerebral palsy (CP) some choose to be mobile by crawling or walking on their knees despite some bipedal walking ability. This motor behavior raises questions; so, we wanted to enhance understanding of the child's choice of mobility.

To explore gross motor abilities in positions with various postural demands focusing on floor mobility among children with CP.

A cross-sectional observational study.

The study was performed at the Neuropediatric Outpatient Department at Karolinska University Hospital.

Thirty-six children with bilateral CP, median age 11.2 years, functioning at Gross Motor Function Classification System (GMFCS) level I-IV.

Motor skills using the Gross Motor Function Measure (GMFM-88), and lower leg muscles strength in hip flexors, knee extensors, ankle dorsiflexors and plantarflexors with a hand-held dynamometer were assessed. A Kruskal-Wallis Test with post-hoc Bonferroni corrections were used to compare GMFM percentage (%) scores and muscle strength between the GMFCS levels.

GMFM-88 (%) scores in walking (E) and standing (D) dimensions were significantly higher at GMFCS levels I and II, compared to levels III and IV. In crawling and kneeling (C) level I achieved higher score than levels III and IV, and in sitting (B) than level IV. Muscle strength values in the plantarflexors were significantly higher at GMFCS level I compared to level II.

As expected the children at GMFCS III performed less than those at GMFCS II at high postural demands in GMFM dimensions including standing and walking. Identical GMFM-scores in dimension C confirm similar motor function in items including kneeling and knee walking. Since lower limb muscle strength was similar, the difference in postural behavior between the groups at high level motor activities may be associated with sensorimotor disturbances along with the children's motor disorder.

The GMFM-88, in particular dimension C, including kneeling and walking items can be used as an identification of preference of floor mobility in children with CP. Awareness and understanding of how postural positions affect movement is of importance for prognosis, and physiotherapy.