First aid is in injury.

These methods are not hard, as everybody can to do this, and these are...
Full rest for the survivor, leg injury for put a horizontal position, as rising slightly, as this allows for blood current to ache side and low hematoma and edema.
Apply hard bandage as for normal circulation of blood in injured extremities, as this manipulation is needed in leg dislocation.
And in on injured leg having skin damage like scratches, thus disinfect theirs and put antibacterial plaster.
Affect on injury with cold compresses or ice, or any plastic bottle with cold water or cooling ointment.
As if hurts feel, thus take the analgetic remedy. And if symptoms are not lowered after first aid, and clinical appearances are visible, thus patient needing at the hospital visiting as maybe on these injuries is hide are fractures.