When the ragdoll effects on NPC or protagonist is activated by having them hit by a car, falling, etc., they will not just flap around like a 'lifeless' ragdoll if they are still alive they will brace themselves while getting thrown about. Ragdoll when jumping off a Motorcycle GTA IV. when jumping off a tall building, the subject would land straight then topple over, rather than landing on one foot and immediately falling to the ground).
However, unlike other games that use ragdoll physics, characters in GTA games do not seem to be affected to the fullest extent and still conform to some preset animations, thus assuming a more 'human' posture and not like a dummy being thrown around (eg. Their bodies will conform to any objects realistically and can be moved around by collisions and bullets. Characters no longer lie flat and static on surfaces. The affected model essentially behaves like a 'ragdoll', hence the name. With ragdoll physics, players and NPCs lie on the ground dynamically.
Ragdoll physics is a feature first implemented in Grand Theft Auto IV.
