Breathing is one of the most basic patterns directly related to human movement. There is an intimate association between the activation of the core muscles and mechanisms to increase intra-abdominal pressure which provides lumbar stabilization.
The study deals with the evaluation of the trunk muscle activity during natural breathing in the lying, sitting or standing position. The research sample consisted of 11 students attending Faculty of Sports, University of Prešov who regularly performed strength training and were pain-free in the lumbar spine.
Muscle activity was monitored by surface electromyography in the lying, sitting and standing position. Data were expressed as the percentage of the maximum voluntary contraction.
The results showed higher muscle activity of local stabilizers than global stabilizers in the basic positions. The muscle activity varied depending on the muscle function and whole body position and its segments as well.
Back muscles showed to be more relaxed while lying in contrast to abdominal muscles which participated in breathing to a greater extent. Sitting position required increased activity of local stabilizers and to maintain the vertical position of the trunk higher activity of erector spinae muscle activity was necessary.
The highest activity of transversus abdominis muscle was found in the standing position. Muscle activity of local stabilizers was more evenly distributed in the standing position and higher than that of the global stabilizers.