Some evidence suggests that physical activity programs might promote short-term weight gain and bone mineralization in preterm infants .
Current evidence does not support the routine use of physical activity programs in preterm infants .
BACKGROUND Lack of physical stimulation may contribute to metabolic bone disease of preterm infants , result ing in poor bone mineralization and growth .
Physical activity programs combined with adequate nutrition might help to promote bone mineralization and growth .
OBJECTIVES The primary objective was to assess whether physical activity programs in preterm infants  improve bone mineralization and growth and reduce the risk of fracture .
Subgroup analysis : • Given that the smallest infants are most vulnerable for developing osteopenia ( Bishop 1999 ) , a subgroup analysis was planned for infants with birth weight < 1000 g.•  Calcium and phosphorus intake may affect an infant 's ability to increase bone mineral content ( Kuschel 2004 ) .
Assisted Exercise and Bone Strength in Preterm Infants
Studies have previously demonstrated that brief ( 4 weeks ) passive range-of-motion exercise is beneficial for bone development in very low birth weight ( VLBW ) preterm infants . However , the optimal duration of exercise for bone development in preterm infants is yet unknown . The aim of the present study was to examine the effect of 8 weeks of assisted exercise on bone strength and metabolism in VLBW premature infants . Sixteen infants ( mean ± st and ard error of the mean birth weight 1,009 ± 55 g and gestational age 27.3 ± 0.3 weeks ) were r and omly assigned into exercise ( n = 8) and control ( n = 8) groups . The intervention started at the first week of life and involved 8 weeks of daily passive extension and flexion range-of-motion exercise of the upper and lower extremities . Biochemical markers of bone turnover were measured at enrollment and after 8 weeks . Bone strength was measured weekly by quantitative ultrasound measurement of tibial bone speed of sound ( SOS ) . Bone SOS decreased significantly in the control group ( −108.1 ± 33.7 m/second , P < 0.0001 ) during the study period , while remaining stable in the exercise group ( 11.3 ± 22.8 m/second ) . The main beneficial effect of exercise occurred in the first 4 weeks of the intervention . There were no significant differences in the bone turnover marker changes between the groups . There is a significant postnatal decrease in bone SOS in VLBW preterm infants . Eight weeks of assisted range-of-motion exercise attenuates the decrease in bone strength and may decrease the risk of osteopenia in premature infants
Some evidence suggests that physical activity programs might promote short-term weight gain and bone mineralization in preterm infants .
Current evidence does not support the routine use of physical activity programs in preterm infants .
BACKGROUND Lack of physical stimulation may contribute to metabolic bone disease of preterm infants , result ing in poor bone mineralization and growth .
Physical activity programs combined with adequate nutrition might help to promote bone mineralization and growth .
OBJECTIVES The primary objective was to assess whether physical activity programs in preterm infants  improve bone mineralization and growth and reduce the risk of fracture .
Subgroup analysis : • Given that the smallest infants are most vulnerable for developing osteopenia ( Bishop 1999 ) , a subgroup analysis was planned for infants with birth weight < 1000 g.•  Calcium and phosphorus intake may affect an infant 's ability to increase bone mineral content ( Kuschel 2004 ) .