Between the two sections of rectus
abdominis muscle there is a thin tendon called linea alba.
Not exact matches
The fact is that
there are no upper and lower abs — the rectus
abdominis is a single
muscle and you can't really isolate any portion of it independently.
There was no difference in rectus
abdominis muscle activity between the exercises.
Comparing the split squat with the back squat, Andersen et al. (2014) used a 6RM load in resistance - trained males and found that
there was no difference between the exercises in respect of the rectus
abdominis muscle activity but that the split squat displayed greater external obliques
muscle activity than the standard back squat.
There are four main abdominal
muscles to consider: the rectus
abdominis, the external oblique, the internal oblique, and the transverse
abdominis.
The rectus
abdominis and external oblique display moderate levels of
muscle activity in the squat and deadlift but
there is no difference in the levels of
muscle activity between these lifts.
Haggmark et al. (1979) found that the proportion of type I
muscle fiber across the rectus
abdominis, internal and external oblique was 55 — 58 %, although
there was considerable inter-individual variability.
There was a trend towards higher rectus
abdominis muscle activity in the long lever plank with posterior pelvic tilt compared to the long lever plank without posterior pelvic tilt (109 % vs. 90 % of MVIC).
There was no difference in rectus
abdominis muscle activity between conditions.
The rectus
abdominis and external oblique display moderate levels of
muscle activity during squat and deadlift variations, but
there is no difference in
muscle activity of the abdominals between the squat and deadlift.