341 Clinical measures of tibial bone force in runners

Objectives/Goals: Tibial bone stress injuries are running injuries that have a high risk of recurrence. Tibial load contributes to the development of bone stress injuries; however, this variable is clinically inaccessible. The objective of this study is to establish a relationship between tibial load during running and clinical tests to support safe return to running. Methods/Study Population: Thirty-two healthy recreational runners (13 F, 19 M, age 23.6 y, height 1.77 m, mass 73.71 kg, weekly volume 16.91 miles) ran at a self-selected pace on an instrumented treadmill for 5 minutes, while a 7-camera motion capture system collected whole body kinematics. Inverse dynamics were used to calculate ankle joint reaction forces and moments which were then used in a musculoskeletal model to calculate tibial axial force. Single leg heel-raise endurance, hand-held dynamometry ankle strength, and Y-balance tests were also assessed. Linear mixed models will be used to determine relationships between tibial force during running and strength and balance measures. Results/Anticipated Results: Data analysis is ongoing. Based on preliminary data, it appears that peak tibial bone force during running may demonstrate a relationship with lower extremity strength and balance. Clustering participants into “high” and “low” tibial force production during running may help identify specific ranges of strength and balance assessment outcomes that are appropriate for clinical goals. Discussion/Significance of Impact: The results of this study will attempt to establish relationships between tibial bone loads during running and strength and balance assessments that are clinically feasible. Results have potential to directly impact clinical practice by providing objective measures that may be used as surrogates for tibial bone force in a clinical setting.