Waist Circumference, a Clinical Measurement for the Activity of Transversus Abdominis

Abstract

Objectives: Improving the timing and endurance of the deep abdominal muscles, notably transversus abdominis (TrA), is a known protocol for improving spinal stability. TrA is the deepest abdominal muscle, and monitoring its activity is a difficult task. Ultrasound and pressure biofeedback have been employed for monitoring the activity of TrA; however, these methods are expensive, not always available in all clinical settings, and their application requires formal training. The purpose of this study was to examine the use of a broadly known method, i.e., changes in the waist circumference, to monitor the activity of TrA. Methods: The study was carried out on 14 subjects following a pilot study of 5 participants. The thickness of TrA measured by ultrasound was considered the standard indicator for activity of TrA and was compared with simuObjectives: Improving the timing and endurance of the deep abdominal muscles, notably transversus abdominis (TrA), is a known protocol for improving spinal stability. TrA is the deepest abdominal muscle, and monitoring its activity is a difficult task. Ultrasound and pressure biofeedback have been employed for monitoring the activity of TrA; however, these methods are expensive, not always available in all clinical settings, and their application requires formal training. The purpose of this study was to examine the use of a broadly known method, i.e., changes in the waist circumference, to monitor the activity of TrA. Methods: The study was carried out on 14 subjects following a pilot study of 5 participants. The thickness of TrA measured by ultrasound was considered the standard indicator for activity of TrA and was compared with simultaneous measurement of waist circumference. Results: A significant criterion validity between the thickness of TrA and the waist circumference was established (Pearson correlation=-0.71, P=0.001), indicating an inverse relationship between changes in the thickness of the transversus abdominis muscle and waist circumference. Discussion: This result confirmed the hypothesis that changes in the waist circumference could be employed as a suitable indicator for the activity of TrA.ltaneous measurement of waist circumference. Results: A significant criterion validity between the thickness of TrA and the waist circumference was established (Pearson correlation=-0.71, P=0.001), indicating an inverse relationship between changes in the thickness of the transversus abdominis muscle and waist circumference. Discussion: This result confirmed the hypothesis that changes in the waist circumference could be employed as a suitable indicator for the activity of TrA.