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.

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.

Physical Performance Measures of Flexibility, Hip Strength, Lower Limb Power, and Trunk Endurance in Healthy Navy Cadets: Normative Data and Differences Between Sex and Limb Dominance.

ABSTRACT: Lopes, TJA, Simic, M, Alves, DdS, Bunn, PdS, Rodrigues, AI, Terra, BdS, Lima, MdS, Ribeiro, FM, Vilão, P, and Pappas, E. Physical performance measures of flexibility, hip strength, lower limb power, and trunk endurance in healthy navy cadets: Normative data and differences between sex and limb dominance. J Strength Cond Res 35(2): 458-464, 2021-The objectives were to provide normative data on commonly used physical performance tests that may be associated with musculoskeletal injuries in Navy cadets and assess for sex and limb dominance differences. A large cohort of Navy cadets were assessed for physical performance tests of flexibility (ankle dorsiflexion range of motion and sit and reach), isometric hip strength, lower limb power (single-leg hop), and trunk endurance (plank and side plank tests). Besides providing normative data tables, sex and limb dominance differences were assessed by a 2-way mixed analysis of variance. A total of 545 Brazilian Navy cadets (394 men) representing 79% of the cadets in the Academy participated. Normative reference values were reported as mean ± SD, 95% confidence interval and percentiles. For tests of muscle strength, power, and endurance, men performed better than women (p < 0.001). For flexibility tests, women achieved greater distances than men for the sit and reach test (p < 0.001), but no difference for ankle dorsiflexion (p = 0.51). Overall, there were no clinically relevant differences between limbs. In conclusion, normative data for commonly used physical performance tests were provided. Although no clinically relevant side-to-side differences were found, men presented higher values for lower limb strength and power, as well as trunk endurance than women, whereas women demonstrated increased flexibility. Valuable normative data are provided to professionals who work with young, active populations from the injury prevention or rehabilitation perspective because the current study may help professionals to identify athletes or cadets whose performance is outside the normative values and may be at risk for injury.