Reduction of Risk for Low Back Injury in Theater of Operations
Condition: Lower Back Injury
MeSH terms: Wounds and Injuries; Back Injuries
Study type: Interventional

Summary: 
      The investigators will conduct a controlled clinical trial with U.S. Army soldiers training
      to become combat medics. The purpose of this study is to determine if a 11-week, high
      intensity exercise program targeting the low back muscles using specialized equipment will
      result in a 25% increase in low back muscular strength and endurance compared with a lower
      intensity general core stability exercise.
    

Detailed description: 
      Background Low back injury is responsible for the largest percentage of non-battle injuries
      in the theater of operations and is a large contributor to non-expiration of active service
      attrition in the US Armed Forces. Weakness and poor endurance of the back muscles are
      associated with low back injury. Targeted, high intensity exercise approaches using
      specialized equipment to develop the strength and endurance of the "weak link" muscle group
      (the lumbar extensors) have been shown to reduce risk for low back injury in high-risk
      civilian workers, but have not been widely implemented in military settings.

      Objective/Hypothesis Specific Aim: In a controlled clinical trial, the investigators will
      assess the effectiveness of a high intensity progressive resistance exercise training program
      targeting the lumbar extensors to improve lumbar extensor muscular strength and endurance in
      US Army soldiers.

      Hypothesis: A high intensity progressive resistance exercise for the lumbar extensors will
      result in a 25% increase in lumbar extensor muscular strength and endurance compared with
      control following the 11-week intervention.

      Study Design A mixed methods, two-arm, controlled clinical trial with cluster randomization
      will be conducted. The sampling frame will be soldiers training to become combat medics from
      one domestic US Army base. Soldiers will be randomly assigned (by platoon) to one of two
      interventions - experimental or control. All participants at a given platoon will receive the
      same intervention and all interventions will be carried out at the US Army base, in addition
      to the soldiers' usual physical fitness training program. Participants randomized to the
      experimental group (strengthening exercise) will perform lumbar extensor muscle progressive
      resistance exercise using standardized protocols. Exercise training will consist of 1 set of
      high intensity progressive resistance exercise for lumbar extensors on specialized equipment.
      Participants in the active comparator control group (stabilization exercise) will perform 5
      minutes of low intensity core stabilization exercises on the floor. Interventions will be
      carried out 1X/week for 11 weeks. Outcome measures that will be utilized to test the
      hypothesis of Aim 1 include validated physical fitness tests for lumbar extension muscular
      strength and endurance. Fitness tests will be conducted at baseline and following the 11-week
      intervention period.

      Relevance Soldiers preparing for deployment are in need of advanced technology to help
      improve and optimize the functional capacity of the lumbar extensor muscles. Assuming
      positive results from this study and confirmatory trials, implementation of this targeted
      exercise protocol will maximize resilience in soldiers at high risk for low back injury,
      thereby helping them become more physically fit to counteract the extreme physical demands
      required in combat.
    

Intervention name(s): Lumbar ext. high intensity progressive resistance exercise; Low intensity core stabilization exercise
Intervention type(s): Other; Other
Intervention description(s): 1 active set of 1 exercise, 1x/week, 11 weeks; 1 set of 5 exercises, 1x/week, 11 weeks
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Prevention
Keywords: low back muscular strength and endurance