Daily physical activity in low-risk pre-term infants: positive impact on bone strength and mid-upper arm circumference

Ann Hum Biol. 2011 Sep;38(5):635-9. doi: 10.3109/03014460.2011.598187. Epub 2011 Jul 12.


Background: Prevention of pre-term osteopenia is important because it results in ventilator dependency, fractures in long bones, softening of the ribs or respiratory failure due to bone breaks in newborns.

Aim: The aim of this study was to evaluate the changes in bone strength and anthropometric indices of very low birth-weight (VLBW) pre-term infants undergoing daily physical activity.

Subjects and methods: Forty VLBW and low-risk pre-term infants (n intervention group = 20, n control group = 20) with a birth weight of 800-1600 g and gestational age of 26-32 weeks were recruited. Pre-term infants in the control group were provided with standard nursing care whereas those in the intervention group received a daily physical activity programme in addition to standard nursing care during the study. Before and after the study, anthropometric indices and tibial speed of sound (SOS) values were measured.

Results: In this study the tibial SOS values were found to be increased in the intervention group (p < 0.001) and decreased in the control group (p = 0.002). The increase in percentage of the mid-upper arm circumference of infants was significantly higher in the intervention group than in the control group (p < 0.001).

Conclusion: A daily physical activity programme increased SOS values of the tibia and mid-upper arm circumference in VLBW pre-term infants.

MeSH terms

  • Anthropometry*
  • Arm / anatomy & histology*
  • Biomechanical Phenomena / physiology
  • Bone and Bones / physiopathology*
  • Female
  • Humans
  • Infant, Newborn
  • Infant, Very Low Birth Weight / physiology*
  • Male
  • Motor Activity / physiology*
  • Premature Birth / physiopathology*
  • Risk Factors
  • Sound
  • Tibia / anatomy & histology
  • Tibia / physiology