The pectoralis minor is a small strap like muscle that is underneath (deep) to the pectoralis major. It originates on the third to fifth rib, near the costal cartilages. It’s insertion is on the coracoid process of the scapula. It acts to draw the scapula forward, downward, and inward at nearly equal angles ( think of rounding or shrugging your shoulders forward). This muscle is very often shortened and tight in people due to the high prevalence of desk jobs. This muscle pulls the shoulder blade forward resulting in the muscles in the back(rhomboid and mid traps) being chronically strained. Trigger points that form in the pec minor primarily refer pain over the anterior chest and shoulder, with spillover down the medial arm. Trigger points in the left side can mimic angina.