Purpose: To investigate the association between
physical therapy frequency and gross motor improvement in children with
cerebral palsy (CP).Materials and methods: This is a prospective cohort study of 442 children aged 2-12 years, Gross Motor Function Classification System levels I-V, from the
Cerebral Palsy Follow-up Program and the
Cerebral Palsy Register of Norway. Outcome was change in reference percentiles for the Gross Motor Function Measure (GMFM-66) between two subsequent assessments (N = 1056) analyzed in a linear mixed model.Results: It was a dose response association between
physical therapy frequency and gross motor improvement. Mean change was 4.2 (95% CI: 1.4-7.1) percentiles larger for
physical therapy 1-2 times per week and 7.1 (95% CI: 2.6-11.6) percentiles larger for
physical therapy >2 times per week, compared to less frequent
physical therapy when analyzed in a multivariable model including multiple child and intervention factors. The only statistically significant confounder was number of
contractures which was negatively associated with gross motor improvement.Conclusions: When gross motor improvement is a goal for children with CP, more frequent
physical therapy should be considered.Implications for rehabilitationIn general, the gross motor development of Norwegian children with
cerebral palsy was as expected according to the reference percentiles for the GMFM-66.When gross motor improvement is a goal for children with
cerebral palsy, high-frequency
physical therapy should be considered.Contractures should be addressed in order to optimize gross motor improvement for children with
cerebral palsy.