Regaining functional use of the upper limb after a stroke is a challenging task for the patient, which has a significant impact on the individual's physical, psychological, and emotional well-being. Lack of functional ability in the upper extremities after stroke restricts use and causes asymmetric posture and contracture in daily life, thus exacerbating functional limitations of the upper limb. Also, low upper limb motor function is related to the risk of soft tissue injury during rehabilitation. A patient experienced a stroke may not feel any pain due to subluxation. However, different muscle groups may be vulnerable to overstretching, increased contraction, and premature fatigue. This can decrease the coordination of muscular activity and inhibit the functional use of the upper extremity. The posterior fibers of the deltoid, the supraspinatus, and the infraspinatus are the most important muscles that prevent the subluxation of the glenohumeral joint.