Respiratory changes due to different rocking movement frequencies and amplitudes

Abstract

Introduction. Rocking movements appear to influence sleep and studies suggests a facilitated transition from wake to sleep due to lateral rocking movements. In a recent study of our lab, investigating the effect of different movement directions on relaxation and their potential to promote sleep, an increase in respiration frequency was found. Respiration was increased in all conditions with movement, reaching values close to the movement frequency. The aim of this study was to investigate the effect of different movement frequencies and amplitudes on respiration. Furthermore, it was of interest whether subjects also adapt their respiration to movement frequencies below their spontaneous respiration frequency. Methods. 21 subjects (24–42 years, 12 male) were measured using an actuated bed, moving along a lateral translation. Following movement frequencies were applied: +30%, +15%, −15%, and −30% of subject’s resting respiration frequency during baseline (no movement). Furthermore, two different movement amplitudes were tested. Respiration frequency was measured with a thermistor flow sensor as well as with a respiration belt. Results. An increase in respiration frequency compared to baseline was found for all movement frequencies and amplitudes. No differences between the different movement frequencies as well as between the two different movement amplitudes were observed. Conclusion. Movements along a lateral translation induced an increase in respiration frequency. This increase appeared to be independent of the applied movement frequencies or amplitudes. Furthermore, no synchronization of the respiration frequency to the movement frequency was observed. In particular, subjects did not lower their respiration frequency below their resting frequency.