Shoulder dislocations in those over 40 years of age are usually the result of a fall or a direct blow to the shoulder, whereas in younger patients they often occur as a result of high-impact activities (e.g., sports and motor vehicle collisions).    The injury results from abduction, external rotation, and extension, followed by a posterior-directed force.
DIP and PIP finger dislocations are usually dorsal in direction and associated with axial loading, hyperextension, and ball-catching sports.   MCP finger dislocations are relatively rare and are often associated with accompanying fractures.  
Primary acute patellar dislocations usually occur in young patients engaged in athletic activities. Patients will often state that when the injury occurred the affected leg was planted while they attempted to pivot. Patellar dislocations may also occur following skeletal or muscular dysplasia, which causes patellar laxity as a result of hypermobility or lack of medial restraints. Dysplasia appears to be the most significant contributor to joint instability.    In addition, patellar injuries can occur as a result of external tibial torsion (i.e., tibia rotates outwards). Patella alta refers to an abnormally high patella in relation to the femur. This may also result in dislocation of the patella.
Elbow dislocations usually occur in young patients, and about 50% are sports-related. They are most commonly the result of a fall on an outstretched arm. 
In addition, loose ligaments can appear in a variety of ways and levels of severity. They may be generalised or confined to a few joints. The trait is usually hereditary. Affected patients have joints with a wide range of movement (e.g., "double-jointed" people). Those with loose ligaments may experience sprains or dislocations more frequently. Ehlers-Danlos syndrome is a rare inherited condition characterised by unusually flexible joints, very elastic skin, and fragile tissues. It may be the cause of widespread laxity of connective tissue.