Relationship of muscle function to auxology in preterm born children at the age of seven years.

BACKGROUND/AIMS: To characterize the relationship between muscle function and auxology in preterm born children. METHODS: Forty-five preterm born children (birth weight < or =1,500 g with mean +/- SD: 1,069 +/- 281 g; median of gestational age: 29 weeks; 50% multiple births) were analyzed for auxological parameters (weight, height) and muscle function at the age of 7 years. Maximal isometric grip force (MIGF) and ground reaction forces of goal-directed counter-movement jumping were measured using the Preston dynamometer and the Leonardo force plate. MIGF, peak jump force (PJF), peak jump power (PJP) and the maximal velocity of take-off (V(max)) were analyzed for their relationship to perinatal risk factors and actual auxological parameters. RESULTS: With reference to age, weight-standard deviation score (SDS) and height-SDS were lower than in the reference population. With reference to height, MIGF-SDS and PJP-SDS were lower than in reference individuals. Children with intraventricular hemorrhage (IVH) had lower PJP-SDS and V(max) than children without IVH. PJP-SDS was lower than PJF-SDS in children with IVH. CONCLUSION: Analyses showed a discrepancy between maximal force and power due to a decline of V(max) in children with IVH.

Postural control at 7 years of age after preterm birth with very low birth weight.

OBJECTIVES: To measure postural control in extremely preterm infants with a birth weight of less than 1,500 g in comparison to full-term infants at 7 years of age and healthy adults. PATIENTS AND MAIN OUTCOME MEASURES: On a Balance Master computerized force plate, static and dynamic postural control was measured in 21 full-term 7-year-old children, 44 extremely preterm 7-year-old children, and 19 healthy adults. The test battery consisted of the modified clinical test of sensory interaction on balance, the rhythmic weight shift, the walk across, and the tandem walk tests. INTERVENTION: Diagnostic, prospective, single-center cohort study. RESULTS: Static and dynamic postural control was significantly better in adults than in children at 7 years of age. In most parameters, static and dynamic postural control was not significantly different between full-term and preterm infants with very low birth weight at 7 years of age. Only the ratio of intended to extraneous movement, that is, the left-right directional control, was significantly lower during the left-right rhythmic weight shift for almost all parameters in the study group of preterm infants. CONCLUSION: Postural control still is not fully developed in infants at early school age. At this age, formerly extremely preterm infants without major neurological disorders have almost caught up to the postural control of healthy full-term subjects.