Physical activity programs for promoting bone mineralization and growth in preterm infants

Area of Science:

• Neonatal care and developmental pediatrics
• Pediatric physical therapy and rehabilitation

Background:

• Preterm infants are at risk for metabolic bone disease due to inadequate physical stimulation, impacting bone mineralization and growth.
• Physical activity interventions, combined with proper nutrition, are hypothesized to enhance bone health in this vulnerable population.

Purpose of the Study:

• To evaluate the efficacy of physical activity programs in improving bone mineralization and growth in preterm infants.
• To determine if physical activity interventions reduce the risk of fractures in preterm infants.

Main Methods:

• A systematic review of randomized and quasi-randomized controlled trials was conducted, searching major databases up to September 2006.
• Included studies involved preterm infants receiving structured physical activity (e.g., range-of-motion exercises) for at least two weeks.
• Data extraction and quality assessment were performed independently by reviewers; meta-analysis used standard statistical methods (RR, WMD, CI).

Main Results:

• Six small trials (169 infants) with poor methodological quality were included; none reported allocation concealment, randomization, or blinding.
• Moderate short-term improvements in bone mineralization were observed in two trials; long-term effects at 12 months were not significant.
• Physical activity showed a positive effect on daily weight gain (WMD 2.77 g/kg/d) but not on linear or head growth; significant heterogeneity was noted for linear growth.

Conclusions:

• Weak evidence suggests physical activity may offer moderate short-term benefits in weight gain and bone mineralization for preterm infants.
• The clinical significance is questionable due to small effect sizes and low baseline risk; data on harm and long-term effects is insufficient.
• Current evidence does not support routine use; well-designed trials are needed to evaluate effects in high-risk infants, including adverse events and long-term outcomes.