A pulled pectoral muscle results in chest pain and discomfort that may prevent full range of motion in the shoulder and arm, often accompanied by heightened sensitivity to touch. The severity of the injury is ranked in three grades, which are based on the number of muscle fibers torn.
A pulled pectoral muscle may also cause mild swelling in the chest muscles and loss of strength in the arm and shoulder. Severe pulled pectorals may lead to permanent damage. Usually, a pulled pectoral muscle can be detected by a simple physiological exam. Most pectoral strains heal within a few weeks.