A Fracture, is a type of injury in DayZ Standalone.
Fractures are a part of the bone-status effect (added in v1.10) in the game, this status has a maximum of 100 and a minimum of 0. There are 2 types of bone-status effect for arms and legs, only the legs are currently in the game as of 1.10.
The way it works is quite simple, all damage done to that body part (Example: 50% damage due to a fall on your health, also does 50% damage to this bone-status effect). The lower the bone-stat gets the higher the chance to receive a fracture. The bone-status effect does automatically regenerate if you rest between falls. The surface you fall on does not change the bone-status damage except for water, as this gives you no fall damage at all.
Once you receive a fracture, you'll get a special broken bone symbol in your HUD and you'll be forced to the prone position. If you were to stand up and walk you'll receive shock damage (numbers are not known as of now) and you'll go unconscious in 2-3 steps. You will not regenerate your shock damage while standing or crouching, only when you're prone. You can not do the following actions while having a un-splinted fracture; climbing, swimming. These action will kill the player as you go unconscious in the water and drown or climb a ladder and fall to your death. However, you can still drive a car without a splint and walk (Default; LCtrl on PC and holding the analog stick lightly forward on Console).
You can extend the period of walking however, you can use Codeine Pills or a Morphine Auto-Injector. The Codeine Pills will allow you to take 25% more steps before you go unconscious and the Morphine Auto-Injector allows you to take 50% more steps.
To properly fix your fracture, you have to craft a Splint (4 Rags and 2 Short Sticks). With the Splint applied you can not run or jump, however you can climb over small obstacles like garden fences. You can't get another fracture, as long as the Splint is applied, meaning you can fall from higher places, without receiving a 2nd fracture.
You can also heal the fracture over time, this will take a while. As you need max health, max blood, at least 4000 energy and 2500 hydration. When you reach the minimum requirement to start healing your fracture, you have to wait a minimum of 34 minutes depending on the severity of the fracture. This is with the Splint applied, if you have no Splint applied the recovery will take twice as long.
Attacking the infected is also highly unwise, as you take 20 shock damage for a light attack and 35 shock damage per heavy attack. Every time a infected hits you, you'll be forced to the prone position and you will most likely die. Bear Traps also causes fractures when you step on them, even if you have a Splint applied.