After it is splinted and put in a sling, there is not much else you can do to immobilize it. You could have the victim move as little as possible.
The term swathe is sometimes used. This is bandage or wrapping that covers everything.
swath
Swathe
Swathe
Swathe
A splint and sling are what immobilize the extremity.
Swathe
Swathe
Swathe
Swathe
It is called a swath or binder.
Cloth or improvised swathes of fabric. SABC-Swathe
Cloth or improvised swathes of fabric. SABC-Swathe
Cloth or improvised swathes of fabric. SABC-Swathe
Cloth or improvised swathes of fabric. SABC-Swathe
Cloth or improvised swathes of fabric. SABC-Swathe
A splint and sling are what immobilize the extremity.