Background Increased adiposity is a well-recognised risk factor for tendon injuries in adults. The mechanisms could be excess biomechanical load and/or the low inflammatory condition caused by excess body fat. The issue has not been investigated in children.

Objective To investigate if children (aged 8–12) with elevated body mass index (BMI) or total body fat% (TBF%) and/or abdominal fat% (AF%) experience more overuse injuries than ‘normal’ children, taking into account sport participation and physical activity.

Design A whole body DEXA scan was used to measure TBF% and AF% in 614 schoolchildren (aged 8–12). Standard anthropometric methods were used to measure waist circumference, weight and height. Physical activity was measured using the MTI accelerometer GT3. Complaints, injuries and sport participation were reported by answering text messages on a weekly basis (SMS-track). If an injury was reported, the child was seen and evaluated by a clinician (physiotherapist, chiropractor or orthopaedic surgeon), and clinical evaluation using ultrasound or MRI was performed when necessary, only diagnosed injuries were included.

Main outcome measurements The primary outcome measures are the number and duration of diagnosed overuse injuries and the impact of BMI, TBF%/AF% will be analysed using cox regression for recurrent events as described by Wei, L. J., D. Y. Lin, and L. Weissfeld. 1989. The analyses will be adjusted for age, sport participation and objectively measured physical activity.

Results and Conclusion Results and conclusion from 2 years follow-up will be reported at the conference.