Does Working in the Military Increase Risk of Lumbosacral Strain?
Yes, military service substantially increases the risk of lumbosacral strain, with this injury representing one of the most prevalent diagnoses for back disability in Army personnel. 1, 2
Evidence of Increased Risk
Military personnel face markedly elevated rates of lumbosacral strain compared to civilian populations due to the unique physical demands of service:
Lumbosacral strain is the leading cause of back disability in U.S. Army personnel, identified as one of the two most prevalent diagnoses (along with intervertebral disc syndrome) among 41,750 disability cases analyzed. 1
Army physical training is the primary cause of lumbosacral strains in both male and female service members during basic training and operational duties. 2
60-80% of military basic training injuries are overuse injuries, with 80-90% affecting the lower extremities and spine, including lumbosacral strain. 3
Injury rates during military basic training range from 22-67% depending on service branch and training intensity, with cumulative injury rates of 42-67% in Army 8-week basic training alone. 3
Primary Risk Factors in Military Settings
The military environment creates specific conditions that dramatically increase lumbosacral strain risk:
Load-Related Factors
Heavy equipment weight directly predicts low back pain episodes, with each additional kilogram of equipment worn increasing odds of moderate or worse LBP by OR=1.01 during deployment. 4
Duration of body armor wear is a critical predictor, with each additional hour per day wearing body armor increasing LBP risk by OR=1.16 for moderate or worse pain and OR=1.13 for all LBP. 4
Repetitive carrying of heavy objects creates mechanical loading on lumbar vertebrae, leading to cumulative trauma disorders and degenerative changes. 5
Occupational Demands
Infantry and Cavalry units have elevated risk due to greater load-bearing requirements and operational demands. 4
Walking patrol time increases risk, with OR=1.01 per hour per week spent on patrol. 4
Tactical vehicle time (21-40 hours/week) and prolonged sitting with body armor both contribute to increased lumbosacral strain through altered spinal postures. 4, 6
Training Parameters
Total training mileage is the most important determinant of injury risk, with military studies documenting thresholds above which training increases injury without improving fitness. 3
Frequency, duration, and intensity of physical training all correlate with injury rates in a dose-response manner, but military personnel cannot modulate these factors unlike civilian exercisers. 3
Modifying Factors
Protective Factors
Higher baseline aerobic fitness reduces injury risk, with those in the lowest tertile of VO2 max having 55% injury incidence versus 39% in the highest tertile. 3
Greater muscular endurance protects against injury, with women completing the most push-ups having 38% injury incidence versus 57% for those completing the least. 3
Higher fitness scores decrease LBP risk by OR=0.99 per unit increase in fitness score. 4
Vulnerability Factors
Lower baseline fitness dramatically increases risk, with the slowest runners having 3.2 times the odds of injury compared to the fastest. 3
Older age increases risk by OR=1.04-1.06 per year. 4
History of previous LBP increases risk by OR=2.94 for developing LBP during deployment. 4
Clinical Implications
The combination of non-modifiable training demands, heavy load carriage, and prolonged equipment wear creates a uniquely high-risk environment for lumbosacral strain in military personnel. 1, 2, 4 Unlike civilian populations who can adjust training parameters when minor injuries occur, military personnel must maintain prescribed training and operational schedules, preventing natural injury mitigation strategies. 3
Injuries account for approximately 50% of healthcare visits in military populations, with injury-related limited duty days vastly exceeding illness-related limitations (rate ratio of 22:1 in one Army study). 3 This represents substantial morbidity affecting combat readiness and long-term quality of life.
Common Pitfalls
Assuming equal risk across all military occupations is incorrect—specific jobs (Infantry, Cavalry) carry significantly higher risk and require targeted prevention strategies. 4
Ignoring baseline fitness levels misses the most modifiable risk factor—pre-deployment fitness optimization should be prioritized. 3, 4
Focusing solely on acute injuries overlooks the cumulative trauma mechanism—lumbosacral strain in military personnel often results from repetitive loading rather than single events. 5, 1