The shoulder, or pectoral, girdle is composed of the clavicles and the scapulae. Shoulder-girdle weakness refers to lack of strength of the muscles attaching to these bones, that is, lack of strength of the muscles around the shoulders. The phenotype is Shoulder girdle muscle weakness (HP_0003547). Also known as: Muscle weakness, shoulder-girdle, Shoulder girdle weakness, Shoulder weakness, Weak shoulder muscles.