Some people wear sweatbands or wristbands, but not everyone does.
it is called a "sleeve" its to keep sweat off your shooting arm
All Of your muscles mainly your arm and lg muscles.
to keep there arm muscle warmed up so they shoot consistently through the entire game and because it loooks awesome
Basketball players wear sleeves on the arm they shoot with so it stays warm. In addition it is an extension of the wrist sweat bands from the old days, keeping the sweat from running down their arm and onto their shooting hand. Keeping their shooting hand dry is important for feel on the ball when passing, dribbling and shooting.
Really doesn't matter which arm you put your shooting sleeve on, although some basketball players like to put it on their right hand if they are right-handed, or thier left if they are left-handed. Try it with both and see.
Basketball jerseys are normally sleeveless, because players get hot while playing. It has also become a popular style among players.
I have no idea why
A football players wear a thin white band on the arm to protect the tendons near the elbow. The pressure from the band minimizes pain and injury to that area.
I have no idea why
it should defintly so players can shoot better i wish i envented that
NFL players usually wear a hard cast, if they are able to play with a broken bone. The hardness of the cast protects them from further injury.
you will wear a cast or a brace