Relationship of Muscle Function to Auxology in Preterm Born Children at the Age of Seven Years

TLDR

The study aims to characterize how muscle function relates to growth parameters in children born preterm at age seven. The authors assessed maximal isometric grip force and counter‑movement jump forces in 45 preterm children at age seven using a dynamometer and force plate. Results showed that preterm children had lower weight, height, grip force, and jump power compared to reference peers, and those with intraventricular hemorrhage exhibited further reductions in jump power and take‑off velocity, indicating a force–power mismatch.

Abstract

To characterize the relationship between muscle function and auxology in preterm born children.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.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.Analyses showed a discrepancy between maximal force and power due to a decline of V(max) in children with IVH.