Using Wearable Sensor Technology to Analyze Running Technique and Prospective Running-Related Injuries During United States Military Cadet Basic Training.

Abstract

Background: Running biomechanics have been linked to the development of running-related injuries in recreational and military runners.

Purpose/hypothesis: The purpose of this study was to determine if personal characteristics or running biomechanical variables are associated with running-related injury incidence or time to injury in military cadets undergoing training. It was hypothesized that a rearfoot strike pattern, greater rate of impact, or a lower step rate would be related to a greater running-related injury incidence and a decreased time to injury.

Study design: Cohort study; Level of evidence, 2.

Methods: Military cadets wore an on-shoe wearable sensor that analyzed biomechanical variables of foot strike pattern, rate of impact, running pace, step rate, step length, and contact time during cadet basic training (60 days). Running-related injuries during cadet basic training were determined by medical record review. Personal and running variables between the injured and uninjured cadets were compared using independent t tests and chi-square analyses. Time to injury and hazard ratios (HRs) were estimated using Kaplan-Meier survival curves and Cox proportional hazard regression models, respectively.

Results: Of the 674 cadets who completed the study, 11% sustained a running-related injury. A significantly greater proportion of the injured participants were female (χ² = 7.95; P = .005) and had a prior history of injury (χ² = 7.36; P = .007). Univariate Cox proportional hazard regression models revealed greater injury risk in females (HR, 1.96; 95% CI, 1.22-3.16; P = .005) and cadets with a prior injury history (HR, 1.86; 95% CI, 1.18-2.93; P = .008). After adjusting Cox models for prior injury, females were found to be at a 1.89 times (95% CI, 1.17-3.04; P = .009) greater risk of injury. Running biomechanical variables were not associated with injury risk.

Conclusion: Study results indicated that non-modifiable risk factors such as female sex and prior injury history increased the risk of running-related injury in cadets undergoing military training. Running biomechanical variables measured by the wearable sensor were not associated with injury in this study.