The musculus rectus abdominis probably is one of the most popular muscles of the human body. Not only is this muscle responsible for the very desirable six pack shape of the stomach. It also plays an important role in protecting our organs and stabilizing the pelvis and spine.
Side trunk stretches increase the mobility of the lumbar spine. Especially, the deep abdominal muscles with the quadratus lumborum will be stretched.
The muscles of the human body are all-rounders. It is fascinating what our musculature is able to do. Besides steering the locomotor system our more than 600 skeletal muscles have a lot of other very important functions.