Bone Abstracts

Children with cerebral palsy who are unable to walk independently are prone to lower limb muscle weakness which contributes to pain, deformity and functional loss. As a result of these motor difficulties the children are less physically active than their unimpaired peers and subsequently at greater risk of reduced bone density. This pilot study introduced a novel mobility device, running bikes, to a group of non-ambulant children with cerebral palsy to investigate if it was a feasible mode of weight-bearing exercise.

Fifteen children with cerebral palsy aged 4–12 years were recruited from two specialist schools. All children were unable to walk independently, with Gross Motor Function Classification System Levels IV n=10 and V n=5). The children used the running-bikes in their specialist schools three times weekly for 12 weeks, assisted by their physiotherapists. Ability to use the running bike and bone quality was assessed pre and post intervention. Bone quality was assessed by quantitative ultrasound (QUS) technique of the calcaneus (Sonost-3000). The main values of QUS are speed of sound (SoS m/s), broadband attenuation (dB/MHz) and bone quality index (BQI).

Ability to use the running bike significantly improved over the 12 weeks (P=0.000). The mean distance travelled per session increased from 51m pre-intervention to 123m post-intervention. The mean pre-intervention QUS scores for the left limb were: BUA 49.2; SOS 1504.24; BQI 58.2. The mean post-intervention QUS scores were BUA 52.0, SOS 1510.4; BQI 63.8. Paired t-test showed a significant difference between the BQI scores P=0.037, whilst no significant difference was found for the BUA (P=0.24) or SOS scores (P=0.12).

This pilot study has shown that despite their level of disability, running bikes are a feasible mode of exercise for this group of children. This study was not powered to show significant changes in bone quality. Despite this the QUS data showed positive signs of improvement over the short follow up period which is encouraging. Further studies are needed to elucidate the role of running bike use on bone strength in non-ambulant children with cerebral palsy.

This study was funded by Sparks, the children’s medical research charity.

Disclosure: The authors declared no competing interests.