Avulsion of the profundus insertion occurs most commonly in the ring finger. The exact reason for this predilection is unknown. Clinical observation of patients with this injury reveals that a common finding is that the ring fingertip is usually more prominent or "longer" than any other fingertip during grip. A laboratory investigation shows that during grip the ring fingertip becomes 5 mm more prominent than any other digit in 90% of subjects and that it absorbs more force than any other finger during pull-away testing. These factors contribute to the susceptibility of the ring finger to the profundus avulsion injury.