Obliques - The oblique muscles, consisting of the external and internal obliques (musculus obliquus externus and musculus obliquus internus), run along the sides of the torso. They are essential for rotating the upper body, bending to the side, and assisting in forward flexion. Additionally, they stabilize the torso and help protect the spine.

Lower Back - The erector spinae muscle runs along your spine and helps you extend your back and stand upright.

Side Delts - The lateral part of the deltoid muscle, also known as the lateral shoulder, is located on the outside of the shoulder. It is the main muscle responsible for lifting the arm sideways. The lateral shoulder is particularly active when the arm is extended away from the body, such as during lateral raises or lifting objects to the side. It plays a key role in arm abduction and shoulder stabilization.

Abs - The rectus abdominis, also known as the "abs," runs vertically along the front of the abdomen. It is responsible for bending the torso forward, such as during sit-ups, and lifting the pelvis. This muscle stabilizes the torso, supports the spine, and helps maintain good posture.