Balloon-based exercise enhances abdominal activation: a comparison between one expert and one novice with chronic low back pain.

[Purpose] While forced exhalation with balloon-blowing has been reported to facilitate abdominal muscle activity, few studies have examined its effects using imaging. We aimed to compare abdominal muscle morphology across three conditions, end-inspiration, end-forced expiration, and end-forced expiration with balloon-blowing, between a balloon-blowing exercise expert and a novice with chronic low back pain, assessed using ultrasound imaging. [Participants and Methods] A 61-year-old male expert and a 51-year-old male novice participated. The thicknesses of the transversus abdominis, internal oblique, and external oblique were measured using ultrasound imaging during end-inspiration, end-forced expiration, and end-forced expiration with balloon-blowing. The thickness and contraction ratios, calculated by dividing the thickness at end-forced expiration by that at end-inspiration, were compared within and between participants. [Results] The expert demonstrated a 1.33 mm thicker transversus abdominis and a 4.95 mm thicker internal oblique than those of the novice at end-inspiration. Balloon-blowing increased all muscle thicknesses in both participants compared with end-inspiration. The contraction ratios of the muscles during forced expiration with balloon blowing were 1.14- to 1.80-fold higher than the ratios at end-forced expiration in both participants. [Conclusion] These findings suggest the potential usefulness of balloon-blowing for activating abdominal muscles, especially in individuals with chronic low back pain.