Correlation Between Abdominal Muscle Thickness and Maximal Expiratory Pressure

Area of Science:

• Physiology
• Biomechanics
• Respiratory Medicine

Background:

• Abdominal muscles, including the rectus abdominis, external oblique, internal oblique, and transverse abdominis, are crucial for generating expiratory pressure.
• Understanding the relationship between the thickness of these muscles and maximal expiratory pressure is important for respiratory function assessment.

Purpose of the Study:

• To investigate the association between the thickness of individual abdominal muscles and maximal expiratory pressure in healthy young males.
• To determine which abdominal muscle's thickness is most strongly correlated with expiratory power.

Main Methods:

• Thirty-nine healthy male volunteers underwent B-mode sonography to measure the thickness of the rectus abdominis, external oblique, internal oblique, and transverse abdominis muscles.
• Maximal expiratory pressure was measured using a spirometer.
• Pearson correlation coefficients were calculated to analyze the relationship between muscle thickness and expiratory pressure.

Main Results:

• A significant positive correlation was found between rectus abdominis muscle thickness and maximal expiratory pressure (r=0.571, P<.001).
• Weaker, non-significant correlations were observed for the external oblique (r=0.297, P=.066), internal oblique (r=0.267, P=.100), and transverse abdominis (r=0.022, P=.894) muscles.

Conclusions:

• Rectus abdominis muscle thickness demonstrates a stronger association with maximal expiratory pressure compared to other abdominal muscles.
• These findings suggest that the rectus abdominis may be a primary contributor to expiratory force generation.