Long Distance Running, Bone Density, Physiological Load Measures by Accelerometry and Joint Space Narrowing of the Knee: A Prospective Study

Objectives: Running is known to exert a positive impact on overall health. Its potential harm or benefit on knee osteoarthritis (OA) has, however, not been thoroughly explored, mainly due to lack of quantifiable metric to link running derived parameters with OArelated biomechanics. This study sought to investigate whether joint space width (JSW), an indicator of OA, is associated with a) acceleration magnitude at the knee level (associated with collision impact) and b) weekly running distance. Design: This was a cross-sectional study using an open-label design. Methods: We included 76 healthy volunteers (from sedentary individuals to trained runners). JSW was measured using standard fixedflexion radiographs. A wearable 3-axial accelerometer was placed on the skin at the tibia plateau level to estimate acceleration magnitude during collision impact. An algorithm was designed to identify the exact instance of collision impact and measure its acceleration magnitude. Metaphysis density was assessed using tomodensitometry at the proximal tibia level (DENSISCAN). A multi-linear model was applied to assess whether running distance, collision acceleration, and metaphysis density were independent JSW predictors. Results: Lower tibia collision acceleration was a predictor of JSW, whereas no association was found between JSW and running distance or metaphysis density. Conclusions: Our results indicate that collision impact at the knee level (estimated by acceleration) may predict increased OA risk, while weekly running distance does not. While this collision impact may be related to running technique, further research is warrant to better understand the mechanism underlying high collision impact and its associated risks.