Gait characteristics in 6-year-old children born extremely preterm

This study aimed to clarify the characteristics of motor impairments and their relationship with perinatal risk factors in children born extremely preterm (EP). Forty children aged 6 years born EP (n = 10) and at term (n = 30) were enrolled. Patients with cerebral palsy or intellectual disabilities were excluded from the EP group. Data on the following items were collected: one-leg standing time, two-step test, grip strength, five-times sit-to-stand test, and Developmental Coordination Disorder (DCD) questionnaire. The Gait Deviation Index (GDI), an index of gait quality, and its symmetry ratio were evaluated using three-dimensional gait analysis. The results were compared between the two groups, and their correlations with perinatal risk factors in the EP group were analyzed. The EP group exhibited shorter one-leg standing times, lower two-step test scores, lower grip strength, and lower total and general coordination scores on the DCD Questionnaire compared with the control group. Regarding gait function, the EP group had a lower GDI and a higher GDI symmetry ratio. Birth weight was positively correlated with the GDI. Body weight at 36 weeks postmenstrual age was positively correlated with the GDI and DCD Questionnaire total and general coordination scores.

Children born EP exhibited potentially decreased gait quality and increased gait quality asymmetry, in addition to decreased muscle strength, decreased balance function, and increased DCD traits. Lower birth weight and the subsequent weight gain may be related to decreased gait quality and increased DCD trait in school-aged children.

• Developmental coordination disorders occur in approximately 20-50% of children born extremely preterm (EP). • Decreased muscle strength has been reported in children and adults born EP.

• Children born EP showed decreased gait quality and increased gait asymmetry using three-dimensional gait analysis in addition to decreased muscle strength, decreased balance function, and increased DCD traits. • Lower birth weight and subsequent weight gain were associated with decreased gait quality and increased DCD traits in school-aged children born EP.