Trunk endurance, posterior chain flexibility, and previous history of musculoskeletal pain predict overuse low back and lower extremity injury: a prospective cohort study of 545 Navy Cadets

Abstract Objective To investigate predictors of low back and lower extremity musculoskeletal injury in a cohort of Naval cadets. Design Prospective Cohort Study Methods 545 Naval cadets (Males, n = 394, 72%) were followed-up over eight months. Nine variables were investigated as predictors: history of musculoskeletal symptoms in the last 12 months, ankle dorsiflexion range of motion, sit and reach test, isometric hip abduction and external rotation strength, alignment during the single leg squat test, single leg hop test for distance, prone plank and side plank tests. All injuries that required medical attention were registered. Predictive associations were examined using univariable and multivariable logistic regression analyses. Results The incidence of all injuries was 7%. Cadets who failed the 60-second plank test (OR = 3.3; 95% CI, 1.2-8.8, P =  0.04), had ≤18 cm in the sit and reach test (OR= 4.0; 95% CI, 1.4-11.2, P =  0.01), or reported pain in the last 12 months in two or more body regions (OR= 2.7; 95% CI, 1.02-7.3, P =  0.04), had greater odds of sustaining an overuse injury. No predictors were identified for acute injuries. Conclusion Decreased trunk endurance on the prone plank test, reduced posterior chain flexibility on the sit and reach test, and a history of pain reported in two or more sites in the last 12 months were predictors of overuse injuries in Naval cadets. Assessment and intervention of these modifiable risk factors may be clinically relevant in injury screening and prevention.