Date Available


Year of Publication


Degree Name

Master of Science (MS)

Document Type

Master's Thesis




Kinesiology and Health Promotion

First Advisor

Dr. Mark Abel


Special Weapons and Tactics (SWAT) officers constitute a subgroup of specialized law enforcement officers that perform a variety of tactical operations while wearing approximately 40 kg of tactical gear. Lower back pain is a prevalent musculoskeletal injury suffered by SWAT officers. Tactical gear places significant stress on the lower back. Thus, it is important to quantify the effect that tactical gear has on muscle activation levels of torso musculature while performing occupational tasks. Electromyography was evaluated on 20 male subjects (age: 34.7±4.5 yr.; height: 1.79±.10 m; body mass: 91.53±17.32 kg; mass of gear: 13.82±1.90 kg) while performing four tactical tasks (standing, rifle walk, sitting, & shield walk) with and without gear. Electromyography was evaluated bilaterally on the erector spinae, rectus abdominis, and external oblique muscles. The dominant erector spinae (mean delta: +0.16%) and external oblique (mean delta: -0.124%) demonstrated significant changes in muscle activation with the addition of gear, which may indicate increased spinal compression. There were also trends of increased co-activation of core musculature with the addition of gear. The rifle walk and shield walk task mean muscle activations were significantly higher than the standing and sitting tasks. The shield walk produced the highest mean activations for each muscle. Physical training for SWAT officers should emphasize exercises that simulate task-specific movement patterns without gear to decrease the spinal compression associated with load carriage.