Upper extremity dislocation/instability refers to the displacement of the bones in the shoulder, elbow, or wrist joints, which can occur when the joint is forced out of its normal position. Dislocations typically happen due to trauma, such as a fall or a sports injury, and can result in pain, swelling, and immobility in the affected area. Instability, on the other hand, involves a recurrent tendency of the joint to dislocate or sublux (partially dislocate) due to factors like ligament laxity, previous injuries, or overuse. Both conditions can lead to complications if not properly treated and may require physical therapy to strengthen the surrounding muscles, improve stability, and restore function.