The patient, a 28-year-old female who works as an elementary school teacher, presents with a history of bilateral shoulder joint limitations in internal rotation and adduction since childhood without any identifiable cause. Additionally, she reports experiencing popping sounds and scapular elevation when raising her shoulders. Further inquiry with the patient’s parents revealed that she had a frequent history of colds, fevers, and pneumonia during childhood. Consequently, long-term benzylpenicillin injections were administered bilaterally into the gluteal muscles; however, poor absorption in this region resulted in the formation of local nodules and medication leakage from the injection site. Subsequently, injections were switched to both deltoid muscles. At the age of 5, it was noted that her upper limbs exhibited abduction by 20° along with limited internal rotation and adduction movements. This led to stiffness in shoulder joint mobility where both forearms could not be brought close to the trunk. The patient had received a diagnosis of bilateral posterior shoulder dislocation at multiple medical facilities.