Whole Body Vibration Training in Children With Osteogenesis Imperfecta and Limited Mobility

Children with osteogenesis imperfecta (OI) have impaired bone strength, fractures, weak muscles and limited mobility. Mild to moderate forms of OI (type 1 and 4) may benefit from muscle training that leads to secondary improvement in bone strength (osteogenic treatment). Recent studies in children with cerebral palsy but also OI suggest that Whole Body Vibration Training (WBVT) improves mobility and also bone strength. No randomized controlled trials exist in OI children. This randomized controlled pilot study assesses the effect of 5 months WBVT (2 x 9min/day) on muscle function, mobility, bone structure and density. 24 children \>5 years with OI type 1 and 4 with limited mobility (CHAQ Score ≥0.13) will be randomized into a WBVT group and a control group matched by gender and pubertal stage. Main outcome measure is the change in tibial volumetric BMD, secondary outcomes include a variety of bone, mobility and dynamic muscle function variables.

Osteogenesis imperfecta (OI) is a bone fragility disorder with impaired bone strength, fractures, weak muscles and limited mobility. Mild to moderate forms of OI (type 1 and 4) may not require bisphosphonate therapy but would benefit from muscle training that leads to secondary improvement in bone strength (osteogenic treatment). The mechanostat theory states that bone adapts its strength to mechanical forces mostly imposed by muscle. According to this widely accepted theory, any treatment that strengthens muscle should also strengthen bones. Whole body vibration therapy (WBVT) with side-alternating platforms (Galileo™) uses the body's neuromotor reflex system to train muscles. Recent studies in children with cerebral palsy but also OI suggest that WBVT improves mobility and also bone strength. No randomized controlled trials exist in OI children.

This randomized controlled study assesses the effect of 5 months whole body vibration training (2 x 9min/day) on muscle strength, motor function, bone structure and density. 24 children \>5 years with OI type 1 and 4 with limited mobility (CHAQ Score ≥0.13) will be randomized into a WBVT group and a control group matched by gender and pubertal stage. Children with OI will be recruited from specialist clinics in Birmingham, Manchester and Sheffield, as well as via advertisement on the Brittle Bone Society's homepage. Patients will be equipped with side-alternating vibration platforms for home use and train with increasing intensity. Outcome measures are tested pre- and post 5-months intervention. Dynamic muscle function is measured by mechanography (jumping force plates) and mobility by CHAQ questionnaire and a six-minute walk test. Changes in bone structure and density are assessed by DXA and peripheral QCT of the tibia.

Eligibility Criteria:
Inclusion Criteria:

Patients with mild OI (type 1 and 4; \>5y of age) who need to be at least partly ambulant and have a CHAQ score of greater than 0.13, constituting at least mild disability. Minimum requirement is the ability to rise from a chair.

Informed consent is required from the participant and/or parent/guardian.

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Exclusion Criteria:

* On bisphosphonate treatment for less than 2years (since mobility usually improves during the initial phase treatment).
* Finished bisphosphonate therapy less than 6 months ago
* Recent lower limb fracture \<3months ago, or upper limb fracture which is still in plaster.
* Heart or lung disease, use of steroids (oral, systemic, topical or inhaled, for more than 3 weeks in the last 12 months) or any other bone-active treatment.