Assessment of Rectus Abdominis muscle thickness during isometric trunk and leg lifting exercises using extended field of view (EFOV) ultrasound

Abstract

Aim: The purpose of the present study was to establish which type of exercise is optimal for Rectus Abdominis (RA) muscle, by measuring thickness and length changes using the extended field of view ultrasonography (EFOV US) during different conditions. The second purpose was to estimate the reliability of EFOV US as a muscle morphology assessment tool.Material and methods: Segmental muscle thickness and length of 11 young healthy adults was assessed during 1) rest and isometric 2) trunk lifting, 3) leg lifting and 4) combined trunk and leg lifting exercises with the use of EFOV US.Results: RA muscle thickness was significantly greater during exercises compared to rest (p<0.05). It was also observed that proximal and proximal-middle segments showed significantly less thickness and length compared to distal-middle and distal segments (p<0.05). Even though no differences in thickness were observed between the exercises, leg lifting and combined trunk and leg lifting exercises affected more the distal segment of RA muscle (p<0.05). Moreover, no significant differences in length between exercises was found (p>0.05). Further, EFOV US displayed excellent reliability as the ICC values ranged from 0.82 to 0.97.Conclusions: According to our observations it seems that exercises that induce lifting of the legs might be more effective for the distal parts of RA muscle. EFOV appears to be a reliable diagnostic tool for measuring RA muscle thickness during rest and contracting states.

Investigation of Structural Changes in Rectus Abdominis Muscle According to Curl-Up Angle Using Ultrasound with an Extended Field of View

“…It is presumed that this is because the ratio of thickness change increases at a similar level in each section. In addition, we found a reduced length of each section at all angles compared to the rest position, which was also similar to the length variation in RA shown in previous studies [ 34 ]. In a previous study, the influence on contraction was examined but the effect of curl-up angles was not studied.…”

“…To examine the movement of these muscles, it is necessary to check the area around the ROI using an EFOV with the panorama imaging technique of ultrasound. The EFOV can acquire a wide FOV image compared to the conventional B-mode and show superior precision and significance when compared with MRI images [ 34 , 35 ]. Information on the vertical length during muscle contraction is essential to confirm the structural characteristics of the RA along the vertical axis.…”

“…But, it is difficult to obtain the information only with B-mode images, and few studies have been conducted to measure the vertical length of the RA using ultrasound. In addition, a previous study investigated the change according to the section of RA for two exercises such as trunk and leg lifting using EFOV, but not for curl-up angles [ 34 ]. Another study examined the change in EO, IO, TrA, and RA when a curl-up was performed [ 36 ].…”

Spinal Muscle Thickness and Activation during Abdominal Hollowing and Bracing in CrossFit® Athletes

“…For example, Urquhart et al [ 15 ] used a 3.5 cm inter-electrode distance, about 5 cm from the xiphoid process, while we used electrodes with a 1 cm inter-electrode distance which were placed on the midline between the xiphoid process and pubic symphysis. Greater inter-electrode distances may be more representative of the underlying muscle activation, but they are prone to crosstalk errors than shorter inter-electrode distances [ 34 ], while the RA architecture may vary along the muscle–tendon unit [ 35 ], thus affecting the recorded EMG patterns.…”