Descriptive Epidemiology of Musculoskeletal Injuries Presenting to an Embedded Holistic Health and Fitness (H2F) Team in a United States Army Stryker Brigade, October 2021-September 2022

Abstract Introduction In 2020, the U.S. Army began implementation of the Holistic Health and Fitness (H2F) system to reduce musculoskeletal injury (MSKI) rates and expedite rehabilitation after injury. The purpose of this study was to describe the rates and characteristics of incident MSKIs evaluated by H2F physical therapists (PTs) and athletic trainers (ATs) in a U.S. Army Stryker brigade combat team from October 2021 to September 2022. Materials and Methods In this retrospective observational study, we used negative binomial models and the H2F injury tracker and Army administrative data to estimate MSKI incidence rates for the overall brigade and within strata of battalion, age, sex, rank, race, and ethnicity. We repeated these estimates when standardized to the overall brigade population by battalion, age, sex, and rank. We characterized distributions of time from injury to evaluation, limited duty days (i.e., time-loss), and activity at time of injury. This research was determined exempt by academic and military Institutional Review Boards. Results The embedded H2F PTs and ATs evaluated 2,140 incident MSKIs in the brigade (4,780 person-years) for an overall rate of 39.1 MSKIs per 1,000 person-months. Battalion rates ranged from 31.8 (field artillery) to 50.0 (infantry) and did not change substantially after standardization. Embedded H2F PTs and ATs evaluated 63% of MSKIs within 1 week of onset, managed 59% without assigning time-loss, and found 51% of MSKIs occurred during unit physical fitness training. Conclusions These findings are consistent with the a priori expectation that embedded providers and the H2F system expedited access to MSKI evaluation and treatment. A strength of this study was our ability to estimate MSKI incidence rates and characterize MSKI evaluated in the H2F environment using a novel injury tracker coupled with administrative data. A limitation is that because of data deidentification, we could not measure cumulative time-loss. This descriptive observational study will help inform the findings of subsequent research on the effect of H2F implementation on MSKI outcomes.