Comparison of muscular activities in the abdomen and lower limbs while performing sit-up and leg-raise

Abstract

[Purpose] This study compared the muscle activities of sit-up and leg-raise. [Subjects and Methods] The subjects of this study were healthy students in their 20s. For electromyography of sit-ups and leg-raises in the supine position, 5 muscle groups of the abdomen were selected for the attachment of sensors: the upper and lower rectus abdominis, external oblique, rectus femoris, and the iliopsoas. SPSS 20.0 was used for the statistical analysis. One-way ANOVA with repeated measures of all factors was performed to verify the statistical significance of the measurements taken for the muscle activities and follow-up verification was made with the Bonferroni post hoc test. [Results] Sit-up and leg raise showed a significant difference. The eccentric sit-up exercise elicited a significant increase in the activation of the abdominal muscle. The leg raise and eccentric sit-up exercises elicited significant increases in the activation of hip flexor muscle. [Conclusion] The eccentric sit-up had the most outstanding effect on the abdominal muscles involved in stability of the trunk.

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

“…This is in line with the findings of Kim et al [5] who also did not observe differences in RA thickness between curl-up and leg raises. Results on EMG differences between these particular trunk exercises are conflicting as some studies [3,12,14] found that combined trunk and leg lifting exercises display greater EMG activation of RA than leg lift while others reported greater RA activation either during trunk lift [9] or during leg lift [13]. Comparisons with our findings is difficult as these studies [3,13,14] used EMG during dynamic movements as opposed to US thickness during isometric efforts implemented in this study.…”

“…Other studies set the upper and lower RA 3 cm vertically up and down from the umbilicus, respectively [5] while other investigators took measurements from the second portion [20] or the midpoint between portions [21] below and above the umbilical level. Third, in some studies exercises were performed at low intensity [21] or with active movement [9,14] which is different to maximum isometric contractions monitored in this study. Finally, another factor that could affect comparisons between studies is the angle of trunk and hip flexion at which the measurements were taken.…”

“…RA muscle strengthening exercises come in different forms including trunk flexion ("trunk lift") [4,5,[7][8][9] and hip flexion ("leg lift") [2,10,11] or both [3,12]. However, it is unclear which form of exercise is the most effective in recruiting abdominal musculature.…”

“…However, it is unclear which form of exercise is the most effective in recruiting abdominal musculature. Some studies have found greater electromyographic (EMG) activation of the RA during leg lifting compared to trunk lifting exercises [13] but others reported the opposite [9]. On the contrary, other studies have found that combined trunk and leg lifting exercises result in greater RA EMG activity [3,12,14], especially when exercises are performed against resistance provided by accessories (such as a "power wheel roll-out") [3] or when exercises are performed on an unstable surface (such as "Jacknife" and "Rollouts") [14].…”

Core Muscle Activity during Physical Fitness Exercises: A Systematic Review

“…The exercise is similar to the curl-up or crunch, but the main difference is that the aim of the sit-up is to lift the trunk until the participant is upright in a semi-seated position. This exercise may vary depending on specific protocols (e.g., sit-ups on unstable surfaces) [16,25,58,60].…”