Serratus Anterior Muscle: Rib, Arm, Finger, Upper Back Pain
The serratus anterior muscle contributes to pain down the side of the ribs, around the shoulder blade, chest, arm, hand, and fingers.
Side Stitch
Intercostal Muscles: Rib Pain, Breathing Difficulty
The intercostal muscles are found between the ribs. The muscles can contribute to pain in and around the rib cage. They are also a major contributor to pain in the sides and in between the ribs known as a side stitch.
Diaphragm Muscle: Chest Pain, Rib Pain, Difficulty Breathing
The diaphragm is a muscle found under the lower ribs. It can contribute to breathing problems, pain in the chest, ribs, and can cause sharp pain in the side known as side stitches.