Look at any sports today, and you'll find participants and umpires using different hand signals to communicate with each other. Mostly, hand signals are used to regulate the game as well as keep track of the scores. The same rule is applied in badminton, which is termed as badminton hand signals. With the advent of modernization, often it becomes difficult to communicate verbally during the game, basically with the umpires. One of the main reasons behind this phenomenon is the player's attention is too engrossed in the game.

In addition, the players come from different backgrounds and cultures. So, it becomes difficult to communicate with each other. Above all, when the crowds gets excited, it gets difficult to adjust scores and manage the game properly if verbal communication solely is used in the game. To overcome this difficulty hand signals are used in badminton. In the game, other than the players, the referee, the umpire, the service judge and the line judge use badminton hand signals to regulate the game.

The hand signals used by the umpires in the game of badminton include:

Raising right hand straight above his head – If the misconduct of the player is enough to apply the rule 16.8. The umpire would perform this hand signal and call the name of the player, warning for misconduct.
These are some of the hand signals followed by the service judges:

Raise the right arm in front - The service judge would raise his right arm slightly, flex the elbow and keep the palm vertically facing the opposite direction. The service judge performs this signals to indicate that the shaft of the racket when hitting the shuttle was not below the level of the wrist. This signal can also be applied to reveal that while serving the racket and/or the shaft of the racket was not facing downwards when hitting.

Lift the palm horizontally facing downwards – The signal is made below the level of abdomen followed by moving the palm left and right. This signal conveys that the shuttle, was not hit under the level of the waist during serving.

Extend the right leg and pointing the hand towards the foot – This hand signal indicates that either one or both feet were not in the service court till the serve was completed.

Besides, the service judge also perform hand signals like placing the palm of the right hand on right side of the abdomen, keeping the palm facing the left side of the body, with fingers pointing downwards and pointing the fingers of the left hand to the palm of the right hand with the palm of the left hand facing the abdomen. All these hand signals display that the first point of contact with the shuttle was not the base of the shuttle.

These are some of the hand signals followed by the line judges:
To indicate that the shuttle landed outside he extends both his hands horizontally to the sides of his body.
To reveal that the shuttle has fallen inside correctly the line judge would point his hand to the line.
To covey that the he's not sure about the shuttle landing to the umpire, the service judge will close both his eyes with hands.