Calcified Tissue International

, Volume 99, Issue 3, pp 237–242 | Cite as

The Effect of Assisted Exercise Frequency on Bone Strength in Very Low Birth Weight Preterm Infants: A Randomized Control Trial

  • Ita LitmanovitzEmail author
  • Hedva Erez
  • Alon Eliakim
  • Sofia Bauer-Rusek
  • Shmuel Arnon
  • Rivka H. Regev
  • Gisela Sirota
  • Dan Nemet
Original Research


We aimed to assess whether a twice daily assisted exercise interventional program will have a greater effect on bone strength compared to a once daily intervention or no intervention in very low birth weight (VLBW) preterm infants. Thirty-four very VLBW preterm infants (mean BW 1217 ± 55 g and mean gestational age 28.6 ± 1.1 weeks) were randomly assigned into one of three study groups: twice daily interventions (n = 13), a once daily intervention (n = 11), and no intervention (control, n = 10). The intervention was initiated at a mean of 8 ± 2.4 days of life and continued for 4 weeks. It included passive extension and flexion range-of-motion exercise of the upper and lower extremities. Bone strength was measured at enrollment and after 2 and 4 weeks using quantitative ultrasound of tibial bone speed of sound (SOS, Sunlight Omnisense™). At enrollment, the mean bone SOS was comparable between the twice daily interventions, once daily intervention and control groups (2918 ± 78, 2943 ± 119, and 2910 ± 48 m/s, respectively). As expected, the bone SOS declined in all groups during the study period (−23.6 ± 24, −68.8 ± 28, and −115.8 ± 30 m/s, respectively, p < 0.05), with a significantly attenuated decrease in bone strength in the twice daily intervention group (p = 0.03). A twice daily intervention program of assisted range-of-motion exercise attenuates the decrease in bone strength and may decrease the risk of osteopenia and future fractures in VLBW preterm infants.


Osteopenia Physical activity Quantitative ultrasound Speed of sound 



Internal departmental sources.

Author’s Contribution

Dr. Ita Litmanovitz conceptualized and designed the study, drafted the initial manuscript and approved the manuscript as submitted. Hedva Erez enrolled the infants into the study and performed the assisted exercise. Prof. Alon Eliakim was involved in the study design, interpretation of the results, and reviewed and revised the final draft of the manuscript. Dr. Sofia Bauer-Rusek was responsible for bone QUS measurements and approved the final version of the manuscript. Dr. Shmuel Arnon designed the data collection and revised the final draft of the manuscript. Dr. Rivka Regev was involved in data collection, and reviewed and revised the manuscript. Dr. Gisela Sirota carried out the nutritional management and anthropometric measurements, and reviewed and revised the manuscript. Prof. Dan Nemet designed the study, carried out the statistical analysis, and reviewed and revised the final draft of the manuscript.

Compliance with Ethical Standards

Conflict of Interest

Ita Litmanovitz, Hedva Erez, Alon Eliakim, Sofia Bauer-Rusek, Shmuel Arnon, Rivka H. Regev, Gisela Sirota, and Dan Nemet have no conflict of interest relevant to this article to disclose.

Human and Animal Rights and Informed Consent

This study was approved by the institutional human research committee of Meir Medical Center, Kfar Saba, Israel. Preterm infants born at the Medical Center were eligible for study participation if they met the following criteria: BW < 1500 g, BW appropriate for GA, postnatal age of less than 2 weeks, and the provision of informed parental consent.


  1. 1.
    Forbes GB (1976) Calcium accumulated by the fetus. Pediatrics 1976(57):976–977Google Scholar
  2. 2.
    Ziegler EE, O’Donnel AM, Nelson SE, Fomon SJ (1976) Body composition of the reference fetus. Growth 40:329–341PubMedGoogle Scholar
  3. 3.
    James JR, Condon PJ, Truscott J, Horsman A, Arthur R (1986) Osteopenia of prematurity. Arch Dis Child 61:871–876CrossRefPubMedPubMedCentralGoogle Scholar
  4. 4.
    Sharp M (2007) Bone disease of prematurity. Early Hum Devel 83:653–658CrossRefGoogle Scholar
  5. 5.
    Lee SM, Namgung R, Park MS, Eun HS, Park KI, Lee C (2012) High incidence of rickets in extremely low birth weight infants with severe parenteral nutrition-associated cholestasis and bronchopulmonary dysplasia. J Korean Med Sci 27:1552–1555CrossRefPubMedPubMedCentralGoogle Scholar
  6. 6.
    Viswanathan S, Khasawneh W, McNelis K, Dykstra C, Amstadt R, Super DM, Groh-Wargo S, Kumar D (2014) Metabolic bone disease: a continued challenge in extremely low birth weight infants. J Parenter Enteral Nutr 38:982–990CrossRefGoogle Scholar
  7. 7.
    Moyer-Mileur L, Luetkemeler M, Boomer L, Chan GM (1995) Effect of physical activity on bone mineralization in premature infants. J Pediatr 127:620–625CrossRefPubMedGoogle Scholar
  8. 8.
    Moyer-Mileur L, Brunstetter V, McNaught TP, Gill G, Chan GM (2000) Daily physical activity program increases bone mineralization and growth in preterm very low birth weight infants. Pediatrics 106:1088–1092CrossRefPubMedGoogle Scholar
  9. 9.
    Litmanovitz I, Dolfin T, Friedland O, Arnon S, Regev R, Shainkin-Kestenbaum R, Lis M, Eliakim A (2003) Early physical activity intervention prevents decrease of bone strength in very low birth weight infants. Pediatrics 112:15–19CrossRefPubMedGoogle Scholar
  10. 10.
    Chen H-L, Lee C-L, Tseng H-I, Yang S-N, Yang R-C, Jao H-C (2010) Assisted exercise improves bone strength in very low birthweight infants by bone quantitative ultrasound. J Paediatr Child Health 46:653–659CrossRefPubMedGoogle Scholar
  11. 11.
    Tosun Ö, Bayat M, Güneş T, Erdem E (2011) Daily physical activity in low-risk pre-term infants: positive impact on bone strength and mid-upper arm circumference. Ann Hum Biol 38:635–639CrossRefPubMedGoogle Scholar
  12. 12.
    Litmanovitz I, Dolfin T, Regev R, Arnon S, Friedland O, Shainkin-Kestenbaum R, Lis M, Eliakim A (2004) Bone turnover markers and bone strength during the first weeks of life in very low birth weight premature infants. J Perinat Med 32:58–61CrossRefPubMedGoogle Scholar
  13. 13.
    Tomlinson C, McDevitt H, Ahmed SF, White MP (2006) Longitudinal changes in bone health as assessed by the speed of sound in very low birth weight preterm infants. J Pediatr 148:450–455CrossRefPubMedGoogle Scholar
  14. 14.
    Eliakim A, Raisz LG, Brasel JA, Cooper DM (1993) Evidence for increased bone formation following a brief endurance-type training intervention in adolescent males. J Bone Miner Res 8:127–132Google Scholar
  15. 15.
    Myburgh KH (1998) Exercise and peak bone mass: an update. S Afr J Sport Med 5:3–9Google Scholar
  16. 16.
    Slemenda CW, Miller JZ, Hui SL, Reister TK, Johnson CC (1991) Role of physical activity in the development of skeletal mass in children. J Bone Miner Res 6:1227–1233CrossRefPubMedGoogle Scholar
  17. 17.
    Miller ME (2003) The bone disease of preterm birth: a biomechanical perspective. Pediatr Res 53:10–15CrossRefPubMedGoogle Scholar
  18. 18.
    Land C, Schoenau E (2008) Fetal and postnatal bone development: reviewing the role of mechanical stimuli and nutrition. Best Pract Res Clin Endocrinol Metab 22:107–118CrossRefPubMedGoogle Scholar
  19. 19.
    Eliakim A, Nemet D, Friedland O, Dolfin T, Regev RH (2002) Spontaneous activity in premature infants affects bone strength. J Perinatol 22:650–652CrossRefPubMedGoogle Scholar
  20. 20.
    Litmanovitz I, Dolfin T, Arnon S, Regev RH, Nemet D, Eliakim A (2007) Assisted exercise and bone strength in preterm infants. Calcif Tissue Int 80:39–43CrossRefPubMedGoogle Scholar
  21. 21.
    Vignochi CM, Miura E, Canani LH (2008) Effects of motor physical therapy on bone mineralization in premature infants: a randomized controlled study. J Perinatol 28:624–631CrossRefPubMedGoogle Scholar
  22. 22.
    Nemet D, Dolfin T, Litmanovitz I, Shainkin-Kestenbaum R, Lis M, Eliakim A (2002) Evidence for exercise-induced bone formation in premature infants. Int J Sports Med 23:82–85CrossRefPubMedGoogle Scholar
  23. 23.
    Moyer-Mileur LJ, Ball SD, Brunstetter VL, Chan GM (2008) Maternal-administered physical activity enhances bone mineral acquisition in premature very low birth weight infants. J Perinatol 28:432–437CrossRefPubMedGoogle Scholar
  24. 24.
    Schulzke SM, Kaempfen S, Trachsel D, Patole SK (2014) Physical activity programs for promoting bone mineralization and growth in preterm infants. Cochrane Database Syst Rev 4:CD005387PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Ita Litmanovitz
    • 1
    • 4
    Email author
  • Hedva Erez
    • 2
  • Alon Eliakim
    • 3
    • 4
  • Sofia Bauer-Rusek
    • 1
  • Shmuel Arnon
    • 1
    • 4
  • Rivka H. Regev
    • 1
    • 4
  • Gisela Sirota
    • 1
  • Dan Nemet
    • 3
    • 4
  1. 1.Department of NeonatologyMeir Medical CenterKfar SabaIsrael
  2. 2.Department of Physical TherapyMeir Medical CenterKfar SabaIsrael
  3. 3.Department of PediatricsMeir Medical CenterKfar SabaIsrael
  4. 4.Sackler School of MedicineTel-Aviv UniversityTel-AvivIsrael

Personalised recommendations