Physical activity programmes for promoting bone mineralisation and growth in preterm infants

Lack of physical stimulation may contribute to metabolic bone disease of preterm infants, resulting in poor bone mineralisation and growth. Physical activity programmes combined with adequate nutrition might help to promote bone mineralisation and growth.

The primary objective was to assess whether physical activity programmes in preterm infants improve bone mineralisation and growth and reduce the risk of fractures. The secondary objectives included assessment of other potential benefits in terms of complications of preterm birth, length of hospital stay, skeletal deformities, neurodevelopmental outcomes and adverse events.

We searched CENTRAL, MEDLINE, Embase and trial registries in October 2025. We checked the reference lists of included studies and systematic reviews where the subject matter related to the intervention or population examined in this review.

We included randomised controlled trials (RCTs) and quasi-RCTs of preterm infants born at less than 37 weeks' gestational age. We compared physical activity programmes (extension and flexion, range-of-motion exercises) with no organised physical activity programmes.

Our outcomes of interest were bone mineral content and density measured by absorptiometric x-ray techniques at completion of the physical activity programme and at 12 to 24 months' corrected age, fractures at completion of the physical activity programme, body weight gain (g/kg/day) and body length gain (cm/week) during the study period.

We used the Cochrane risk of bias tool (RoB 1).

We synthesised results for each outcome using fixed-effect meta-analysis, where possible. We expressed our results using the mean difference (MD), standardised mean difference (SMD), risk ratio (RR) and risk difference (RD) with 95% confidence intervals (CIs). We used GRADE to assess the certainty of evidence for each outcome.

We identified five new RCTs for this update. In total, we included 15 RCTs enrolling 434 preterm infants (gestational age 26 to 34 weeks) in this review. All RCTs were small (N = 16 to 50), single-centre studies. The trials were similar in design, although they slightly differed in the physical activity protocol. They evaluated whether daily physical activity, varying in duration from three and a half weeks to eight weeks during initial hospitalisation, compared to routine care or tactile stimulation, promoted bone mineralisation and growth. Postnatal age at the start of the physical activity programme varied between less than three days and up to four weeks of age. Methodological quality and reporting of included trials were variable.

We downgraded the certainty of the evidence to low or very low due to risk of bias, inconsistency and imprecision, mainly due to unclear or high risk of bias, substantial heterogeneity, wide confidence intervals or small sample size. Bone mineralisation Physical activity programmes in preterm infants, compared to no standardised programmes, may increase whole-body bone mineral density (g/cm²) (MD 0.11, 95% CI 0.07 to 0.15; I² = 0%; 2 studies, 65 participants; low-certainty evidence). The evidence is very uncertain about the effect of physical activity on the increase of whole-body mineral content (g) during the study period (MD 5.58, 95% CI -0.88 to 12.04; I² = 95%; 2 studies, 65 participants; very low-certainty evidence). No usable evidence was available for bone mineral content at 12 to 24 months' corrected age. Fractures The evidence is very uncertain about the effect of physical activity on the risk of fractures (RR 0.33, 95% CI 0.01 to 7.68; I² not applicable; 3 studies, 102 participants; very low-certainty evidence; two studies have zero events in both arms). Growth during the study period Physical activity may increase gain in body weight (g/kg/day) during the study period (MD 2.98, 95% CI 2.31 to 3.65; I² = 83%; 14 studies, 418 participants; low-certainty evidence), but may result in little to no increase in body length gain (cm/week) (MD 0.05, 95% CI -0.02 to 0.13; I² = 66%; 11 studies, 355 participants; low-certainty evidence).

There is low to very low-certainty evidence on the effect of physical activity programmes, compared to no standardised programmes, on bone mineralisation and growth in preterm infants. Physical activity programmes may increase whole‑body bone mineral density and body weight gain, and may have little to no effect on body length gain compared to no standardised programmes. It is very uncertain whether physical activity programmes have any effect on whole‑body mineral content or the risk of fractures. No adequate data are available on bone mineralisation at 12 to 24 months' corrected age. Given the low to very low-certainty evidence for all outcomes, further large, well-designed RCTs are needed to assess the effects of physical activity programmes on bone mineralisation and growth in preterm infants.

This Cochrane review had no dedicated funding.

Protocol (2005) DOI 10.1002/14651858.CD005387 Original review (2007) DOI 10.1002/14651858.CD005387.pub2 Review update (2014) DOI 10.1002/14651858.CD005387.pub3.