A Normal Breathing Pattern is Important for an Effective Abdominal Hollowing Maneuver in Healthy People: An Experimental Study. Author: Ha SM, Kwon OY, Kim SJ, Choung SD. Affiliation: Department of Physical Therapy, Graduate School, Yonsei University, Wonju, South Korea. Conference/Journal: J Sport Rehabil. Date published: 2013 Aug 12 Other: Word Count: 248 Abstract Context: A normal breathing pattern while performing the abdominal hollowing (AH) maneuver or spinal stabilization exercise is essential or the success of rehabilitation programs and exercises. In previous studies, subjects were given standardized instructions to control the influence of respiration during the AH maneuver. However, the effect of breathing pattern on abdominal muscle thickness during the AH maneuver has not been investigated. Objective: To compare abdominal muscle thickness while performing the AH maneuver under normal and abnormal breathing pattern conditions and to investigate the effect of breathing pattern on the preferential contraction ratio (PCR) of the transverse abdominis. Design: Comparative, repeated-measures experimental study. Setting: University research laboratory. Participants: 16 healthy subjects (male=8, female=8) from a university population. Measurement: A real-time ultrasound scanner was used to measure abdominal muscle thickness during normal and abnormal breathing patterns. A paired t-test was used to assess the effect of breathing pattern on abdominal muscle thickness and preferential contraction ratio (PCR). Results: Muscle thickness in the transverse abdominis and internal oblique muscle was significantly greater under the normal breathing pattern than under the abnormal pattern (p < 0.05). The PCR of the transverse abdominis was significantly higher under the normal breathing pattern compared with the abnormal pattern (p < 0.05). Conclusion: The results indicate that a normal breathing pattern is essential for performance of an effective abdominal hollowing maneuver. Thus, clinicians should consider that patients adopt a normal breathing pattern prior to performing the AH maneuver and monitor transverse abdominis activation during the maneuver. PMID: 23945040